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Patel R, Purohit S, Solanki R, Khunt D, Patel C, Patel R, Parikh S. Development and validation of an analytical method for trace-level quantification of genotoxic nitrosamine impurities in losartan and hydrochlorothiazide fixed-dose combination tablets using ultra performance liquid chromatography triple quadrupole mass spectrometry. Rapid Commun Mass Spectrom 2023; 37:e9488. [PMID: 36740827 DOI: 10.1002/rcm.9488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/22/2023] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
RATIONALE Since June 2018, globally large numbers of pharmaceuticals have been recalled due to the unexpected presence of nitrosamines. Beginning with the class of pharmaceuticals known as sartans, subsequent lines of inquiry included antidiabetic medicines, antihistamines, and antibiotics. A critical review of the U.S. Food and Drug Administration database reveals that the highest number of products recall due to the presence of unacceptable levels of nitrosamines were losartan potassium drug products and their coformulations with other drug substances. The problem can be mainly attributed to naively adopted approval revisions and the lack of sufficient current analytical technologies to detect those contaminants in time. In this work, we developed a specific, selective, accurate, precise, and robust ultra-performance liquid chromatography-triple quadrupole-mass spectrometry (UPLC-TQ-MS/MS) method for the estimation of eight genotoxic nitrosamine impurities in losartan and hydrochlorothiazide (HCTZ) tablets, which is the only fixed-dosage combination approved by the USFDA to treat hypertension. METHODS All the nitrosamine impurities along with the drug substances were separated using an Agilent Pursuit XRs Ultra diphenyl column (150 × 2.0 mm, 2.8 μm) with mobile phase A (0.1% formic acid in water) and mobile phase B (0.1% formic acid in methanol) at a flow rate of 0.4 ml/min using the gradient elution program. The proposed method was validated per ICH (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) Q2 (R1) guidelines to ensure the method is suitable for its intended purpose. RESULTS Limit of detection and limit of quantification were obtained in the range of 0.25-0.5 ng/mL, which was very low compared to levels specified by the USFDA, European Medicines Agency (EMA), and other regulatory authorities that ensure the sensitivity of the method in its entire life cycle. CONCLUSIONS The developed method can be incorporated into an official monograph and applied for routine quality control analysis of losartan and HCTZ fixed-dose combination tablets.
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Affiliation(s)
- Ravi Patel
- Department of Quality Assurance, Graduate School of Pharmacy, Gujarat Technological University, Gandhinagar, India
| | - Sanjay Purohit
- Department of Quality Assurance, Graduate School of Pharmacy, Gujarat Technological University, Gandhinagar, India
| | - Ravisinh Solanki
- Department of Quality Assurance, Graduate School of Pharmacy, Gujarat Technological University, Gandhinagar, India
| | - Dignesh Khunt
- Department of Pharmaceutics, Graduate School of Pharmacy, Gujarat Technological University, Gandhinagar, India
| | - Chhaganbhai Patel
- Department of Medicinal Chemistry, Shri Sarvajanik Pharmacy College, Mehsana, India
| | - Rucha Patel
- Regulatory Affairs Division, JAMP INDIA Pharmaceutical Pvt. Ltd., Ahmedabad, India
| | - Shalin Parikh
- Analytical Development Division, Senores Pharmaceuticals, Ahmedabad, India
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Palli V, Leonis G, Zoupanou N, Georgiou N, Chountoulesi M, Naziris N, Tzeli D, Demetzos C, Valsami G, Marousis KD, Spyroulias GA, Mavromoustakos T. Losartan Interactions with 2-Hydroxypropyl-β-CD. Molecules 2022; 27:molecules27082421. [PMID: 35458617 PMCID: PMC9027256 DOI: 10.3390/molecules27082421] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/03/2022] [Accepted: 04/05/2022] [Indexed: 02/05/2023] Open
Abstract
Losartan potassium salt (LSR) is a well-known antihypertensive drug with proven beneficial effects on human health. Its formulation with the non-toxic 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) could improve its pharmacological profile. Thus, its molecular interactions are studied using a combination of Differential Scanning Calorimetry (DSC), Nuclear Magnetic Resonance (NMR) and Molecular Dynamics (MD). First, its complexation is shown through Differential Scanning Calorimetry as lyophilization provided distinct thermal properties in comparison to the mixture. The complexation is further proved by utilizing the chemical shift changes in the complexation and T1 values. Furthermore, the reversible favorable complexation was shown by MD calculations. Such physical chemical properties provide evidence that this formulation must be further explored through biological experiments.
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Affiliation(s)
- Vasiliki Palli
- Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (V.P.); (G.L.); (N.Z.); (N.G.); (D.T.)
| | - Georgios Leonis
- Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (V.P.); (G.L.); (N.Z.); (N.G.); (D.T.)
| | - Nikoletta Zoupanou
- Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (V.P.); (G.L.); (N.Z.); (N.G.); (D.T.)
| | - Nikitas Georgiou
- Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (V.P.); (G.L.); (N.Z.); (N.G.); (D.T.)
| | - Maria Chountoulesi
- Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (M.C.); (N.N.); (C.D.)
| | - Nikolaos Naziris
- Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (M.C.); (N.N.); (C.D.)
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Demeter Tzeli
- Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (V.P.); (G.L.); (N.Z.); (N.G.); (D.T.)
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave., 11635 Athens, Greece
| | - Costas Demetzos
- Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (M.C.); (N.N.); (C.D.)
| | - Georgia Valsami
- Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (M.C.); (N.N.); (C.D.)
- Correspondence: (G.V.); (T.M.)
| | | | | | - Thomas Mavromoustakos
- Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, 15784 Athens, Greece; (V.P.); (G.L.); (N.Z.); (N.G.); (D.T.)
- Correspondence: (G.V.); (T.M.)
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Foley L, Toney J, Barlow JW, O’Connor M, Fitzgerald-Hughes D, Ramtoola Z. Investigation of the Physical, Chemical and Microbiological Stability of Losartan Potassium 5 mg/mL Extemporaneous Oral Liquid Suspension. Molecules 2021; 26:molecules26020301. [PMID: 33435555 PMCID: PMC7827961 DOI: 10.3390/molecules26020301] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 11/16/2022] Open
Abstract
Extemporaneous oral liquid preparations are commonly used when there is no commercially available dosage form for adjustable dosing. In most cases, there is a lack of stability data to allow for an accurately assigned shelf life and storage conditions to give greater confidence of product safety and efficacy over its shelf life. The aim of this study was to evaluate the physical, chemical and microbiological stability of an extemporaneous oral liquid suspension of losartan potassium, 5 mg/mL, used to treat paediatric hypertension in Our Lady’s Children’s Hospital Crumlin, Ireland. The losartan content of extemporaneous oral suspensions, prepared with and without addition of water, was measured by UV and confirmed by HPLC analysis. Suspensions were stored at 4 °C and room temperature (RT) and were monitored for changes in; pH, colour, odour, re-dispersibility, Total Aerobic Microbial Count, Total Yeast and Mould Count and absence of E. coli. Results showed that suspensions prepared by both methods, stored at 4 °C and RT, were physically and microbiologically stable over 28 days. Initial losartan content of all suspensions was lower than expected at 80–81% and did not change significantly over the 28 days. HPLC and NMR did not detect degradation of losartan in the samples. Suspensions prepared in water showed 100% losartan content. The reduced initial losartan content was confirmed by HPLC and was related to the acidic pH of the suspension vehicle. Physiochemical properties of the drug are important factors for consideration in the selection of suspension vehicle for extemporaneous compounding of oral suspensions as they can influence the quality, homogeneity and efficacy of these preparations.
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Affiliation(s)
- Lisa Foley
- School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, 111 St. Stephen’s Green, Dublin 2, Ireland; (L.F.); (J.T.)
| | - Jennifer Toney
- School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, 111 St. Stephen’s Green, Dublin 2, Ireland; (L.F.); (J.T.)
| | - James W. Barlow
- Department of Chemistry, RCSI University of Medicine and Health Sciences, 123 St. Stephen’s Green, Dublin 2, Ireland;
| | - Maura O’Connor
- Pharmacy Department, Children’s Health Ireland (CHI) at Crumlin, Dublin 12, Ireland;
| | - Deirdre Fitzgerald-Hughes
- Department of Clinical Microbiology, Education and Research Centre, Beaumont Hospital, RCSI University of Medicine and Health Sciences, Dublin 9, Ireland;
| | - Zebunnissa Ramtoola
- School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, 111 St. Stephen’s Green, Dublin 2, Ireland; (L.F.); (J.T.)
- Correspondence: ; Tel.: +353-1-402-8626
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Khan KA, Khan GM, Shah KU, Niazi ZR, Khan H, Ahmad A, -Ur-Rehman F, Shah PA, Ullah A, Tahir M, Jan SU. Design, Preparation and evaluation of various parameters of controlled release matrices of losartan potassium using polymers combination. Pak J Pharm Sci 2020; 33:2231-2237. [PMID: 33832895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Controlled release formulations are administered once a day and reduce frequency of dose and ensuring patient's compliance. In the current research controlled release matrices of losartan potassium formulated with polymeric combinations of ethocel grade 7 with carbopol 934P NF using different concentrations of polymers. In some polymeric tablets, Co-excipients like CMC, Starch, HPMC was added by replacing of 10% of filler in formulations at 10:5. Tablets were prepared by direct compression method and evaluated for physicochemical characteristics. USP Method-1 (rotating basket method) was used to carry out dissolution study in phosphate buffer pH 6.8. Drug release kinetics determined and comparison of dissolution patterns was done with reference tablets. The polymeric combinations well retarded drug release and drug was released by anamolous non-fickian diffusion mechanism. Dissolution profiles of tested tablets and reference tablets were found not similar. Drug release rate was increased by co-excipients. It was concluded from this research work that this polymeric combination can be used efficiently in designing of controlled release martices.
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Affiliation(s)
| | - Gul Majid Khan
- Department of Pharmacy, Quaid-i-Azam University, Islamabad, Pakistan
| | | | | | - Haroon Khan
- Faculty of Pharmacy, Gomal University, D.I.Khan, KPK, Pakistan
| | - Ashfaq Ahmad
- Department of Pharmacy, University of Swabi, KPK, Pakistan
| | | | | | - Aziz Ullah
- Faculty of Pharmacy, Gomal University, D.I.Khan, KPK, Pakistan
| | - Muhammad Tahir
- Faculty of Pharmacy, Gomal University, D.I.Khan, KPK, Pakistan
| | - Syed Umer Jan
- Faculty of Pharmacy and Health Sciences, University of Balochistan, Quetta, Pakistan
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Serna-Galvis EA, Isaza-Pineda L, Moncayo-Lasso A, Hernández F, Ibáñez M, Torres-Palma RA. Comparative degradation of two highly consumed antihypertensives in water by sonochemical process. Determination of the reaction zone, primary degradation products and theoretical calculations on the oxidative process. Ultrason Sonochem 2019; 58:104635. [PMID: 31450293 DOI: 10.1016/j.ultsonch.2019.104635] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/28/2019] [Accepted: 06/10/2019] [Indexed: 05/09/2023]
Abstract
This work compares the sonochemical degradation of losartan and valsartan (antihypertensives) in water. Initially, the suitable operational conditions of ultrasonic power density and frequency were established. Under such conditions, losartan was eliminated in a higher percentage than valsartan, which was associated to differences in their hydrophobicities. Additionally, degradations in presence of isopropanol and ferrous ions confirmed that losartan was closer to cavitation bubble than valsartan. The structures of primary products indicated that sonogenerated hydroxyl radical attacked biphenyl tetrazole moiety (common nucleus of both pharmaceuticals). Then, theoretical calculations were applied to the products to estimate the toxicity, degree of oxidation and probable routes of aerobic biodegradation suggesting a beneficial action of sonodegradation. Finally, the sonochemical degradation of the antihypertensives was carried out in two simulated complex matrices (i.e., seawater and hospital wastewater) and an actual wastewater. Interestingly, the losartan and valsartan eliminations in such waters were similar to the observed in distilled water. This fact indicates the high potentiality of ultrasound to degrade losartan or valsartan in waters containing other substances, even at higher concentrations than these pollutants.
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Affiliation(s)
- Efraim A Serna-Galvis
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia.
| | - Laura Isaza-Pineda
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Alejandro Moncayo-Lasso
- Grupo de Investigación en Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad Antonio Nariño (UAN), Bogotá D.C., Colombia
| | - Félix Hernández
- Research Institute for Pesticides and Water (IUPA), University Jaume I (UJI), Castellón, Spain
| | - María Ibáñez
- Research Institute for Pesticides and Water (IUPA), University Jaume I (UJI), Castellón, Spain
| | - Ricardo A Torres-Palma
- Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia.
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6
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Al-Dmour NS, Abu-Dahab RMN, Evstigneev MP, Kostjukov VV, El-Sabawi D, Hamdan II. Interaction of pseudoephedrine and azithromycin with losartan: Spectroscopic, dissolution and permeation studies. Spectrochim Acta A Mol Biomol Spectrosc 2019; 221:117194. [PMID: 31170609 DOI: 10.1016/j.saa.2019.117194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/18/2019] [Accepted: 05/26/2019] [Indexed: 06/09/2023]
Abstract
This study aims at investigating the potential effect of selected cationic drugs (azithromycin (AZN) and pseudoephedrine sulfate (PSD) on the dissolution profile and intestinal permeation of losartan potassium (LOS) that might occur due to ion pair salt formation. DSC, FT-IR and 1H NMR indicated the formation of ion pair salts between LOS and each of AZN and PSD. Based on NMR chemical shifts calculations, utilizing specialized software, the most likely structures of the salt were proposed and revealed interesting structural features. The obtained ion pair products were shown to have lower aqueous solubilities (water and phosphate buffer pH 6.8) and higher apparent partition coefficient values compared to the parent compound. Neither of the cations affected the dissolution of LOS tablet (Cozaar® 100 mg) in the studied media (HCl pH 1.2 and phosphate buffer pH 6.8). Interestingly, AZN significantly increased the dissolution of LOS in phosphate buffer pH 4.5 (f2 = 33), and an explanation based on distinguished association pattern between AZN and LOS (CH/π) was offered. Employing permeation test across Caco-2 cells monolayer, the apparent permeability coefficient (Papp) of LOS increased significantly (from 0.9 × 10-5 cm/s to 1.8 × 10-5 cm/s) in the presence of the selected cations. Therefore, while the employed cationic drugs were not shown to form ion pair salts under the in-vitro dissolution conditions, they may still participate in significant in-vivo interaction with LOS.
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Affiliation(s)
| | | | - Maxim P Evstigneev
- Department of Physics, Sevastopol State University, Sevastopol, 299053, Russian Federation
| | - Victor V Kostjukov
- Department of Physics, Sevastopol State University, Sevastopol, 299053, Russian Federation
| | - Dina El-Sabawi
- School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Imad I Hamdan
- School of Pharmacy, The University of Jordan, Amman, Jordan.
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Affiliation(s)
- J Brian Byrd
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, and the University of Michigan Hypertension Center, University of Michigan, Ann Arbor (J.B.B.); and the Division of Nephrology, Department of Medicine, and the Stanford Hypertension Center, Stanford University School of Medicine, Stanford, CA (G.M.C., V.B.)
| | - Glenn M Chertow
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, and the University of Michigan Hypertension Center, University of Michigan, Ann Arbor (J.B.B.); and the Division of Nephrology, Department of Medicine, and the Stanford Hypertension Center, Stanford University School of Medicine, Stanford, CA (G.M.C., V.B.)
| | - Vivek Bhalla
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, and the University of Michigan Hypertension Center, University of Michigan, Ann Arbor (J.B.B.); and the Division of Nephrology, Department of Medicine, and the Stanford Hypertension Center, Stanford University School of Medicine, Stanford, CA (G.M.C., V.B.)
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8
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Martínez-Pachón D, Espinosa-Barrera P, Rincón-Ortíz J, Moncayo-Lasso A. Advanced oxidation of antihypertensives losartan and valsartan by photo-electro-Fenton at near-neutral pH using natural organic acids and a dimensional stable anode-gas diffusion electrode (DSA-GDE) system under light emission diode (LED) lighting. Environ Sci Pollut Res Int 2019; 26:4426-4437. [PMID: 29971747 DOI: 10.1007/s11356-018-2645-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 06/25/2018] [Indexed: 06/08/2023]
Abstract
In this work photo-electro-Fenton (PEF) processes using a dimensionally stable anode-gas diffusion electrode (DSA-GDE) system under light emission diodes (LED)-type radiation were used in the degradation of the angiotensin-II-receptor antagonists (ARA II), valsartan (VAL), and losartan (LOS), which are used in the treatment of hypertension diseases, and are considered among the emerging contaminants (ECs). Organic acids as citric, tartaric, and oxalic acids were used as complexing agents of iron ions in order to maintain the performance of the Fenton reaction at near-neutral pH value. The results show that at 3.42 mA/cm2 after 90 min of electro-Fenton (EF) treatment, degradation of 70% of VAL and 100% of LOS were observed. Total degradation of VAL and LOS was reached with a PEF process at the same time with mineralization of 30%. When citric and tartaric acids were used instead of oxalic acid, similar results were obtained, i.e., total degradation of both compounds, LOS and VAL, after 90 min of treatment. The degradation performance can be attributed to the increase of the initial dissolved iron in the system, facilitating the Fe3+/Fe2+ turnover in the catalytic photo-Fenton reaction and consequently, hydroxyl radical (•OH) production. In addition, the increased photo-activity of the complexes can be associated with their high capability to complex Fe3+ and to promote ligand-to-metal charge transfer, which is of key importance to feed Fe2+ to the Fenton process. The results show that the system evaluated was more efficient to eliminate sartan family compounds using LED lighting in comparison with traditional UV-A lamps used in this kind of work. Moreover, three transformation products of VAL degradation and two transformation products of LOS degradation were identified by high-resolution mass spectrometry (HRMS) using hybrid quadrupole-time-of-flight (QTOF) MS and, at the end of the PEF system, the several organic compounds accumulated and no mineralized were effectively treated in a subsequent aerobic biological system.
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Affiliation(s)
- Diana Martínez-Pachón
- Grupo de Investigación en Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá, D.C., Colombia
| | - Paula Espinosa-Barrera
- Grupo de Investigación en Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá, D.C., Colombia
| | - Javier Rincón-Ortíz
- Grupo de Investigación Fundamental y Aplicada en Materiales, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá, D.C., Colombia
| | - Alejandro Moncayo-Lasso
- Grupo de Investigación en Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá, D.C., Colombia.
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Martínez VR, Aguirre MV, Todaro JS, Piro OE, Echeverría GA, Naso LG, Ferrer EG, Williams PAM. Interaction of Zn with Losartan. Activation of Intrinsic Apoptotic Signaling Pathway in Lung Cancer Cells and Effects on Alkaline and Acid Phosphatases. Biol Trace Elem Res 2018; 186:413-429. [PMID: 29651733 DOI: 10.1007/s12011-018-1334-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/03/2018] [Indexed: 02/03/2023]
Abstract
A new losartan [2-butyl-5-chloro-3-[[4-[2-(2H-tetrazol-5-yl)phenyl]phenyl]methyl]imidazol-4-yl]methanol zinc(II) complex [Zn(Los)Cl], was synthesized and characterized. The crystal structure was determined by x-ray diffraction methods. When aqueous solutions of the ligand and the metal were mixed, the known and more soluble powder [Zn(Los)2].3H2O (ZnLos) complex has been obtained. The interactions with phosphatases showed a concerted mechanism displayed by the Zn ions and ZnLos up to 500 μM concentration: a decrease of the acid phosphatase (AcP) associated with an increase in the alkaline phosphatase (ALP) activities. The complex and ZnSO4 showed a cytotoxic behavior on human lung A549 cancer cell line at concentrations higher than 75 μM with reactive oxygen species (ROS) generation and GSH (and GSH/GSSG ratio) depletion. Apoptotic cells were observed using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) method, a mechanism accompanied by upregulation of BAX protein, downregulation of Bcl-XL and release of caspase-3. The BAX/Bcl-XL ratio was found to be significantly higher in cells exposure to ZnLos than cells treated with ZnSO4, in agreement with the higher apoptotic percentage of cells found for the complex. Cell death was found to be produced by apoptosis and no necrosis has been observed. On the contrary, losartan exerted low effects on phosphatases, produced some reduction of cancer cell viability (concentrations > 250 μM, number of apoptotic cells similar to the basal) with low ROS depletion, without alteration of the GSH/GSSG and low BAX/Bcl-XL ratios. In the MRC-5, normal lung fibroblasts cell line only ZnSO4 at concentrations higher than 200 μM displays cytotoxic effects. Graphical abstract Interaction of Zn with losartan. Activation of intrinsic apoptotic signaling pathway in lung cancer cells and effects on alkaline and acid phosphatases.
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Affiliation(s)
- Valeria R Martínez
- Centro de Química Inorgánica (CEQUINOR-CONICET-CICPBA-UNLP), 120 N° 1465, La Plata, Argentina
| | - María V Aguirre
- Laboratorio de Investigaciones Bioquímicas, Facultad de Medicina, UNNE, Moreno, 1240, Corrientes, Argentina
| | - Juan S Todaro
- Laboratorio de Investigaciones Bioquímicas, Facultad de Medicina, UNNE, Moreno, 1240, Corrientes, Argentina
| | - Oscar E Piro
- Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y IFLP (CONICET, CCT La Plata), C.C. 67, 1900, La Plata, Argentina
| | - Gustavo A Echeverría
- Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y IFLP (CONICET, CCT La Plata), C.C. 67, 1900, La Plata, Argentina
| | - Luciana G Naso
- Centro de Química Inorgánica (CEQUINOR-CONICET-CICPBA-UNLP), 120 N° 1465, La Plata, Argentina
| | - Evelina G Ferrer
- Centro de Química Inorgánica (CEQUINOR-CONICET-CICPBA-UNLP), 120 N° 1465, La Plata, Argentina
| | - Patricia A M Williams
- Centro de Química Inorgánica (CEQUINOR-CONICET-CICPBA-UNLP), 120 N° 1465, La Plata, Argentina.
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Khan KA, Khan GM, Jan SU, Rehman A, Mehsud S. Formulation and in vitro evaluation of directly compressed controlled release tablets designed from the Co-precipitates. Pak J Pharm Sci 2018; 31:455-461. [PMID: 29618434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Controlled release dosage forms provide sustained therapeutics effects for prolonged period of time and improve patient compliance. In present study, controlled release co-precipitates of Metoprolol Tartrate and Losartan Potassium were prepared by solvent evaporation method using polymers such as Eudragit RL 100 and Carbopol 974PNF and controlled release tablets were directly compressed into tablets. In-vitro dissolution of controlled release co-precipitates were performed by USP Method-II (paddle method) and tablets were evaluated by USP Method-I (rotating basket method) in phosphate buffer (PH 6.8) using pharma test dissolution apparatus. The temperature was maintained constant at 37±1.0°C and the rotation speed of paddle and basket was kept constant at 100rpm. Drug release mechanisms were determined by applying Power Law kinetic model. The difference and similarity of dissolution profiles test formulations with reference standards were also determined by applying difference factor (f1) and similarity factor (f2). The results showed that the controlled release co-precipitates with polymer Eudragit RL 100 of both the drug extended the drug release rates for 10 hours and those having polymer Carbopol 974P NF extended the drug release rates for 12 hours. The controlled release tablets prepared from controlled release co-precipitates extended the drugs release up to 24 hours with both the polymers. The drug was released by all tests anomalous non fickian mechanism except F1 and F5 do not follow Power Law. The f1 and f2 values obtained were not in acceptable limits except F15 whose values were in acceptable limits. It is concluded from the present study that polymers (Eudragit RL 100 and Carbopol 974P NF) can be efficiently used in development of controlled release dosage forms having predictable kinetics.
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Affiliation(s)
- Kamran Ahmad Khan
- Department of Pharmaceutics, Faculty of Pharmacy, Gomal University, DI Khan, KPK, Pakistan
| | - Gul Majid Khan
- Department of Pharmaceutics, Faculty of Pharmacy, Gomal University, DI Khan, KPK, Pakistan / Department of Pharmacy, Quaid-i-Azam University, Islamabad, Pakistan
| | - Syed Umer Jan
- Faculty of Pharmacy and Health Sciences, University of Balochistan, Quetta, Pakistan
| | - Asimur Rehman
- Department of Pharmaceutics, Faculty of Pharmacy, Gomal University, DI Khan, KPK, Pakistan / Department of Pharmacy, Quaid-i-Azam University, Islamabad, Pakistan
| | - Saifullah Mehsud
- Department of Pharmaceutics, Faculty of Pharmacy, Gomal University, DI Khan, KPK, Pakistan / Department of Pharmacy, Hazara University, Havelian Campus, KPK, Pakistan
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11
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Ahmed M, Ali M, Ayatollahi SA, Esfahanizadeh M, Kobarfard F, Hasan A, Khan KM, Haider SM. Short Communication - Synthesis of drug metal complexes and their influence on human platelet aggregation. Pak J Pharm Sci 2018; 31:587-591. [PMID: 29618452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
During the past few decades the emergence of inorganic medicinal chemistry has been developed novel therapeutic agents. Researcher's perseverance in this branch of chemistry has led them to explore further valuable chemical spaces by synthesizing metal complexes already known pharmacological agents for their potential use. However, it is in its early stage, this methodology has demonstrated metal complexes with better bioactivities than the parent ligand molecules. In this study, transition metal complexes of pyrazinamide (PZ), isoniazid (INH), fluconazole (FCZ), metformin (dimethylbiguanide, DMBG) and losartan potassium (LS-K) were selected to evaluate for their possible anti-platelets aggregation in the light of reports on divalent and trivalent cations like calcium, copper, manganese, magnesium, and cadmium may influence the process of thrombocytic activity and aggregation. The required evaluation was carried out on human plasma through an APACT 4004 platelet aggregation analyzer. Arachidonic acid (ADP) was used to gauge any alteration in platelet shape and aggregation process. The parent drugs showed some anti-platelets aggregation, however, their metal complexes demonstrated better efficacy.
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Affiliation(s)
- Mansoor Ahmed
- Department of Pharmaceutical Chemistry,Faculty of Pharmacy and Pharmaceutical Sciences,University of Karachi, Karachi, Pakistan
| | - Mohsin Ali
- Department of Chemistry, University of Karachi, Karachi, Pakistan
| | - Seyed Abdulmajid Ayatollahi
- Phytochemistry Research Center, Shahid Beheshti university of Medical Sciences, Tehran, Iran / Department of Pharmacognosy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Marjan Esfahanizadeh
- Phytochemistry Research Center, Shahid Beheshti university of Medical Sciences, Tehran, Iran
| | - Farzad Kobarfard
- Phytochemistry Research Center, Shahid Beheshti university of Medical Sciences, Tehran, Iran / Department of Medicinal Chemistry, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Iran
| | - Ameer Hasan
- Department of Pharmaceutical Chemistry,Faculty of Pharmacy and Pharmaceutical Sciences,University of Karachi, Karachi, Pakistan
| | - Khalid Mohammed Khan
- HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Pakistan
| | - Syed Moazzam Haider
- HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Pakistan
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Szkudlarek A, Pentak D, Ploch A, Pożycka J, Maciążek-Jurczyk M. In Vitro Investigation of the Interaction of Tolbutamide and Losartan with Human Serum Albumin in Hyperglycemia States. Molecules 2017; 22:molecules22122249. [PMID: 29258218 PMCID: PMC6149683 DOI: 10.3390/molecules22122249] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 12/09/2017] [Accepted: 12/15/2017] [Indexed: 01/08/2023] Open
Abstract
Serum albumin is exposed to numerous structural modifications which affect its stability and activity. Glycation is one of the processes leading to the loss of the original properties of the albumin and physiological function disorder. In terms of long lasting states of the hyperglycemia, Advanced Glycation End-products (AGEs) are formed. AGEs are responsible for cellular and tissue structure damage that cause the appearance of a number of health consequences and premature aging. The aim of the present study was to analyze the conformational changes of serum albumin by glycation—“fructation”—using multiple spectroscopic techniques, such as absorption (UV-Vis), fluorescence (SFM), circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy and evaluate of possible alteration of binding and competition between tolbutamide (TB, a first-generation sulfonylurea oral hypoglycemic drug) and losartan (LOS, an angiotensin II receptor (AT1) blocker used in hypertension (1st line with a coexisting diabetes)) in binding to non-glycated (HSA) and glycated (gHSAFRC) human serum albumin in high-affinity binding sites. The studies allowed us to indicate the structural alterations of human serum albumin as a result of fructose glycation. Changes in binding parameters, such as association (Ka) or Stern-Volmer (KSV) constants suggest that glycation increases the affinity of TB and LOS towards albumin and affects interactions between them. The process of albumin glycation influences the pharmacokinetics of drugs, thus monitored pharmacotherapy is reasonable in the case of diabetes and hypertension polypharmacy. This information may lead to the development of more effective drug treatments based on personalized medicine for patients with diabetes. Our studies suggest the validity of monitored polypharmacy of diabetes and coexisting diseases.
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Affiliation(s)
- Agnieszka Szkudlarek
- School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Chair and Department of Physical Pharmacy, Jagiellońska 4, Medical University of Silesia, 41-200 Sosnowiec, Poland.
| | - Danuta Pentak
- School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Chair and Department of Physical Pharmacy, Jagiellońska 4, Medical University of Silesia, 41-200 Sosnowiec, Poland.
| | - Anna Ploch
- School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Chair and Department of Physical Pharmacy, Jagiellońska 4, Medical University of Silesia, 41-200 Sosnowiec, Poland.
| | - Jadwiga Pożycka
- School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Chair and Department of Physical Pharmacy, Jagiellońska 4, Medical University of Silesia, 41-200 Sosnowiec, Poland.
| | - Małgorzata Maciążek-Jurczyk
- School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Chair and Department of Physical Pharmacy, Jagiellońska 4, Medical University of Silesia, 41-200 Sosnowiec, Poland
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Salazar C, Contreras N, Mansilla HD, Yáñez J, Salazar R. Electrochemical degradation of the antihypertensive losartan in aqueous medium by electro-oxidation with boron-doped diamond electrode. J Hazard Mater 2016; 319:84-92. [PMID: 27180209 DOI: 10.1016/j.jhazmat.2016.04.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 06/05/2023]
Abstract
In this work the electrochemical oxidation of losartan, an emerging pharmaceutical pollutant, was studied. Electrochemical oxidation was carried out in batch mode, in an open and undivided cell of 100cm(3) using a boron-doped diamond (BDD)/stainless steel system. With Cl(-) medium 56% of mineralization was registered, while with the trials containing SO4(2-) as supporting electrolyte a higher mineralization yield of 67% was reached, even obtaining a total removal of losartan potassium at 80mAcm(-2) and 180min of reaction time at pH 7.0. Higher losartan potassium concentrations enhanced the mineralization degree and the efficiency of the electrochemical oxidation process. During the mineralization up to 4 aromatic intermediates were identified by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Moreover, short-linear carboxylic acids, like oxalic, succinic and oxamic were detected and quantified by ion-exclusion HPLC. Finally, the ability of the electrochemical oxidation process to mineralize dissolved commercial tablets containing losartan was achieved, obtaining TOC removal up to 71% under optimized conditions (10mAcm(-2), 0.05M Na2SO4, pH 7.0 and 25°C and 360min of electrolysis).
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Affiliation(s)
- Claudio Salazar
- Laboratorio de Trazas Elementales y Especiación, Departamento de Química Analítica e Inorgánica, Facultad de Ciencias Químicas, Universidad de Concepción, Edmundo Larenas 129, Concepción 4070371, Chile; Laboratorio de Química Orgánica Ambiental, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Concepción, Edmundo Larenas 129, Concepción 4070371, Chile.
| | - Nicole Contreras
- Laboratorio de Electroquímica Medioambiental, LEQMA, Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, PO-Box 40, Correo 33, Santiago, Chile
| | - Héctor D Mansilla
- Laboratorio de Química Orgánica Ambiental, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Concepción, Edmundo Larenas 129, Concepción 4070371, Chile
| | - Jorge Yáñez
- Laboratorio de Trazas Elementales y Especiación, Departamento de Química Analítica e Inorgánica, Facultad de Ciencias Químicas, Universidad de Concepción, Edmundo Larenas 129, Concepción 4070371, Chile
| | - Ricardo Salazar
- Laboratorio de Electroquímica Medioambiental, LEQMA, Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, PO-Box 40, Correo 33, Santiago, Chile.
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Balwierz R, Jankowski A, Jasinska A, Marciniak D, Pluta J. FORMULATION AND EVALUATION OF MICROSPHERES CONTAINING LOSARTAN POTASSIUM BY SPRAY-DRYING TECHNIQUE. Acta Pol Pharm 2016; 73:1275-1286. [PMID: 29638068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Despite numerous applications of microspheres, few works devoted to the preparation of microspheres containing cardiac medications have been published. This study presents the potential of receiving microspheres containing losartan potassium, based on a matrix containing Eudragit L30D55. The study focuses on the possibilities of controlled release of losartan potassium from microspheres in order to reduce the dosage frequency, and also provides information on the effect of the addition of excipients to the quality of the microspheres. Microspheres are monolithic, porous or smooth microparticles ranging from 1 to 500 microns in size. For the preparation of microspheres containing losartan potassium, the spray-drying method was used. The performed study confirmed that the spray-drying technology used to obtain microspheres meets the criteria of size and morphology of the microparticles. The assessment of the kinetics of losartan potassium release from the examined microspheres demonstrated that the release profile followed the first- and/or zero-order kinetics. The use of spray-drying techniques as well as Eudragit L30D55 polymer matrix to obtain the microspheres containing losartan potassium makes it possible to obtain a product with the required particle morphology and particle size ensuring the release of the active substance up to 12 h.
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Mizera M, Lewadowska K, Talaczyńska A, Cielecka-Piontek J. Computational study of influence of diffuse basis functions on geometry optimization and spectroscopic properties of losartan potassium. Spectrochim Acta A Mol Biomol Spectrosc 2015; 137:1029-1038. [PMID: 25286115 DOI: 10.1016/j.saa.2014.09.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 06/03/2023]
Abstract
The work was aimed at investigating the influence of diffusion of basis functions on the geometry optimization of molecule of losartan in acidic and salt form. Spectroscopic properties of losartan potassium were also calculated and compared with experiment. Density functional theory method with various basis sets: 6-31G(d,p) and its diffused variations 6-31G(d,p)+ and 6-31G(d,p)++ was used. Application of diffuse basis functions in geometry optimization resulted in significant change of total molecule energy. Total molecule energy of losartan potassium decreased by 112.91kJ/mol and 114.32kJ/mol for 6-31G(d,p)+ and 6-31G(d,p)++ basis sets, respectively. Almost the same decrease was observed for losartan: 114.99kJ/mol and 117.08kJ/mol respectively for 6-31G(d,p)+ and 6-31G(d,p)++ basis sets. Further investigation showed significant difference within geometries of losartan potassium optimized with investigated basis sets. Application of diffused basis functions resulted in average 1.29Å difference in relative position between corresponding atoms of three obtained geometries. Similar study taken on losartan resulted in only average 0.22Å of dislocation. Extensive analysis of geometry changes in molecules obtained with diffused and non-diffuse basis functions was carried out in order to elucidate observed changes. The analysis was supported by electrostatic potential maps and calculation of natural atomic charges. UV, FT-IR and Raman spectra of losartan potassium were calculated and compared with experimental results. No crucial differences between Raman spectra obtained with different basis sets were observed. However, FT-IR spectra of geometry of losartan potassium optimized with 6-31G(d,p)++ basis set resulted in 40% better correlation with experimental FT-IR spectra than FT-IR calculated with geometry optimized with 6-31G(d,p) basis set. Therefore, it is highly advisable to optimize geometry of molecules with ionic interactions using diffuse basis functions when accuracy of results is a priority.
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Affiliation(s)
- Mikołaj Mizera
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznań, Poland
| | - Kornelia Lewadowska
- Institute of Molecular Physics, Polish Academy of Science, 60-179 Poznań, Poland
| | - Alicja Talaczyńska
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznań, Poland
| | - Judyta Cielecka-Piontek
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznań, Poland.
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16
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Abdel-Fattah L, Abdel-Aziz L, Gaied M. Enhanced spectrophotometric determination of Losartan potassium based on its physicochemical interaction with cationic surfactant. Spectrochim Acta A Mol Biomol Spectrosc 2015; 136 Pt B:178-184. [PMID: 25315864 DOI: 10.1016/j.saa.2014.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 09/06/2014] [Accepted: 09/10/2014] [Indexed: 06/04/2023]
Abstract
In this study, a simple and sensitive spectrophotometric method was developed for determination of Losartan potassium (LST K), an angiotensin-II receptor (type AT1) antagonist, in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB). The physicochemical interaction of LST K with CTAB was investigated. The effect of cationic micelles on the spectroscopic and acid-base properties of LST K was studied at pH 7.4. The binding constant (Kb) and the partition coefficient (Kx) of LST K-CTAB were 1.62×10(5) M(-1) and 1.38×10(5); respectively. The binding of LST K to CTAB micelles implied a shift in drug acidity constant (ΔpKa=0.422). The developed method is linear over the range 0.5-28 μg mL(-1). The accuracy was evaluated and was found to be 99.79±0.509% and the relative standard deviation for intraday and interday precision was 0.821 and 0.963; respectively. The method was successfully applied to determine LST K in pharmaceutical formulations.
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Affiliation(s)
- Laila Abdel-Fattah
- Analytical Chemistry Department, Faculty of Pharmacy, Misr University for Science & Technology, Al-Motamayez District, P.O. Box 77, 6th of October City, Egypt
| | - Lobna Abdel-Aziz
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Egypt.
| | - Mariam Gaied
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Egypt
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17
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Latha B, Gunasekaran S, Srinivasan S, Ramkumaar GR. Computation and interpretation of vibrational spectra on the structure of Losartan using ab initio and Density Functional methods. Spectrochim Acta A Mol Biomol Spectrosc 2014; 132:375-386. [PMID: 24887499 DOI: 10.1016/j.saa.2014.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 05/04/2014] [Accepted: 05/09/2014] [Indexed: 06/03/2023]
Abstract
The solid phase FTIR and FT-Raman spectra of Losartan have been recorded in the region 400-4000 cm(-1). The spectra were interpreted in terms of fundamental modes, combination and overtone bands. The structure of the molecule was optimized and the structural characteristics were determined by Quantum chemical methods. The vibrational frequencies yield good agreement between observed and calculated values. The infrared and Raman spectra were also predicted from the calculated intensities. 1H and 13C NMR spectra were recorded and resonance chemical shifts of the molecule were calculated. UV-Visible spectrum of the compound was recorded in the region 200-600 nm and the electronic properties HOMO and LUMO energies calculated by TD-HF approach. NBO atomic charges of the molecules and second order perturbation theory analysis of Fock matrix also calculated and interpreted. The geometrical parameters, energies, harmonic vibrational frequencies, IR intensities, Raman intensities, and absorption wavelengths were compared with experimental and theoretical data of the molecule.
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Affiliation(s)
- B Latha
- Department of Physics, Dr. M.G.R. Educational & Research Institute University, Chennai 600095, TN, India; Department of Physics, SCSVMV University, Enathur, Kanchipuram 631561, TN, India
| | - S Gunasekaran
- Research and Development, St. Peter's Institute of Higher Education and Research, St. Peter's University, Avadi, Chennai 600054, TN, India
| | - S Srinivasan
- PG and Research Department of Physics, Presidency College, Chennai 600005, TN, India
| | - G R Ramkumaar
- Department of Physics, C. Kandaswami Naidu College for Men in Anna Nagar East, Chennai 600102, TN, India.
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18
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Jankowski A, Balwiarz R, Marciniak D, Lukowiec D, Plita J. Influence of spray drying manufacturing parameters on quality of losartan potassium microspheres. Acta Pol Pharm 2014; 71:833-841. [PMID: 25362812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A general aim of the research was to develop a technology of manufacturing microspheres with losartan potassium as an active substance, and Eudragit L30D55 as a matrix with the use of spray drying technique. During the first step of the study, optimal values of parameters in spray drying process were established (i.e., operating temperature, peristaltic pump performance, aspiration value). Those values have a crucial effect on morphological parameters, and the size and homogeneity of received particles. In the obtained microspheres, the activity of excipients, which modify morphological properties of microspheres, were tested. Additionally, we studied the impact of the type and amount of plasticizer, as well as the amount of an adopted polymer in proportion to dry matter of losartan potassium, on quality of final product. Triethyl citrate and citric acid, plasticizers tested in reported studies, were also verified. A detailed study of the influence of both plasticizers on the qualities of microspheres containing losartan potassium on Eudragit L30D55 matrix indicated a positive influence of triethyl citrate and a negative influence of citric acid on morphological properties, shape and size of particles. The application of optimal parameters of spray drying and triethyl citrate as a plasticizer in the amount of 10 to 15% allows to obtain microspheres from 1.27 to 7.24 μm.
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Taylor L, Vasudevan SR, Jones CI, Gibbins JM, Churchill GC, Campbell RD, Coxon CH. Discovery of novel GPVI receptor antagonists by structure-based repurposing. PLoS One 2014; 9:e101209. [PMID: 24971515 PMCID: PMC4074120 DOI: 10.1371/journal.pone.0101209] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 06/04/2014] [Indexed: 01/30/2023] Open
Abstract
Inappropriate platelet aggregation creates a cardiovascular risk that is largely managed with thienopyridines and aspirin. Although effective, these drugs carry risks of increased bleeding and drug ‘resistance’, underpinning a drive for new antiplatelet agents. To discover such drugs, one strategy is to identify a suitable druggable target and then find small molecules that modulate it. A good and unexploited target is the platelet collagen receptor, GPVI, which promotes thrombus formation. To identify inhibitors of GPVI that are safe and bioavailable, we docked a FDA-approved drug library into the GPVI collagen-binding site in silico. We now report that losartan and cinanserin inhibit GPVI-mediated platelet activation in a selective, competitive and dose-dependent manner. This mechanism of action likely underpins the cardioprotective effects of losartan that could not be ascribed to its antihypertensive effects. We have, therefore, identified small molecule inhibitors of GPVI-mediated platelet activation, and also demonstrated the utility of structure-based repurposing.
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Affiliation(s)
- Lewis Taylor
- Department of Physiology, Anatomy and Genetics, University of Oxford, Le Gros Clark Building, South Parks Road, Oxford, United Kingdom
| | - Sridhar R. Vasudevan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, United Kingdom
| | - Chris I. Jones
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Hopkins Building, Reading, United Kingdom
| | - Jonathan M. Gibbins
- Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Hopkins Building, Reading, United Kingdom
| | - Grant C. Churchill
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, United Kingdom
| | - R. Duncan Campbell
- Department of Physiology, Anatomy and Genetics, University of Oxford, Le Gros Clark Building, South Parks Road, Oxford, United Kingdom
| | - Carmen H. Coxon
- Department of Physiology, Anatomy and Genetics, University of Oxford, Le Gros Clark Building, South Parks Road, Oxford, United Kingdom
- * E-mail:
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Hung SF, Hsieh CM, Chen YC, Wang YC, Ho HO, Sheu MT. Characterizations of plasticized polymeric film coatings for preparing multiple-unit floating drug delivery systems (muFDDSs) with controlled-release characteristics. PLoS One 2014; 9:e100321. [PMID: 24967594 PMCID: PMC4072683 DOI: 10.1371/journal.pone.0100321] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 05/22/2014] [Indexed: 11/19/2022] Open
Abstract
Effervescent multiple-unit floating drug delivery systems (muFDDSs) consisting of drug (lorsartan)- and effervescent (sodium bicarbonate)-containing pellets were characterized in this study. The mechanical properties (stress and strain at rupture, Young's modulus, and toughness) of these plasticized polymeric films of acrylic (Eudragit RS, RL, and NE) and cellulosic materials (ethyl cellulose (EC), and Surelease) were examined by a dynamic mechanical analyzer. Results demonstrated that polymeric films prepared from Surelease and EC were brittle with less elongation compared to acrylic films. Eudragit NE films were very flexible in both the dry and wet states. Because plasticizer leached from polymeric films during exposure to the aqueous medium, plasticization of wet Eudragit RS and RL films with 15% triethyl citrate (TEC) or diethyl phthalate (DEP) resulted in less elongation. DEP might be the plasticizer of choice among the plasticizers examined in this study for Eudragit RL to provide muFDDSs with a short time for all pellets to float (TPF) and a longer period of floating. Eudragit RL and RS at a 1∶1 ratio plasticized with 15% DEP were optimally selected as the coating membrane for the floating system. Although the release of losartan from the pellets was still too fast as a result of losartan being freely soluble in water, muFDDSs coated with Eudragit RL and RS at a 1∶1 ratio might have potential use for the sustained release of water-insoluble or the un-ionized form of drugs from gastroretentive drug delivery systems.
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Affiliation(s)
- Sheng-Feng Hung
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Chien-Ming Hsieh
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
- Department of Cosmetic Science, Providence University, Taiwan Boulevard, Shalu, Taichung, Taiwan, ROC
| | - Ying-Chen Chen
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Yu-Chun Wang
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Hsiu-O Ho
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
- * E-mail: (MTS); (HOH)
| | - Ming-Thau Sheu
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
- Clinical Research Center and Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei, Taiwan
- * E-mail: (MTS); (HOH)
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Yamashita F, Ohtani H, Koyabu N, Ushigome F, Satoh H, Murakami H, Uchiumi T, Nakamura T, Kuwano M, Tsujimoto M, Sawada Y. Inhibitory effects of angiotensin II receptor antagonists and leukotriene receptor antagonists on the transport of human organic anion transporter 4. J Pharm Pharmacol 2010; 58:1499-505. [PMID: 17132213 DOI: 10.1211/jpp.58.11.0011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Human organic anion transporter 4 (OAT4) is the only member of the OAT family that is expressed in the placenta and also expressed in kidney. Although OAT4 has been shown to transport certain organic anions as well as other members of the OAT family, fewer numbers of substrates have been identified for OAT4 compared with OAT1 and OAT3, suggesting that the substrate specificity of OAT4 is greater than other OAT members. However, the substrate specificity of OAT4 remains to be investigated in detail. The aim of this study was to examine the effects of various drugs on the OAT4-mediated transport of estrone-3-sulfate, a typical substrate of OAT4, by using human embryonic kidney cells stably transfected with OAT4 (HEK-OAT4). HEK-OAT4 cells exhibited concentration-dependent uptake of estrone-3-sulfate, with a Km value of 20.9 ± 3.53 μM. Dehydroepiandrosterone sulfate and probenecid potently inhibited estrone-3-sulfate uptake. We also searched for the potential inhibitors of OAT4 and identified candesartan, candesartan cilexetil, losartan, losartan carboxyl (EXP3174) and valsartan as inhibitors of OAT4, with Ki values of 88.9, 135.2, 24.8, 13.8 and 19.6 μM, respectively. The above angiotensin II receptor antagonists and leukotriene receptor antagonists share a common structural feature, that is the tetrazole group. Although pranlukast is devoid of anionic motifs other than the tetrazole group, it potently inhibited the OAT4-mediated uptake of estrone-3-sulfate, indicating that a tetrazole group may be one important structural feature in substrate recognition by OAT4.
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Affiliation(s)
- Fumiaki Yamashita
- Department of Medico-Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Fukuoka, Japan
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Xu F, Mao C, Liu Y, Wu L, Xu Z, Zhang L. Losartan chemistry and its effects via AT1 mechanisms in the kidney. Curr Med Chem 2009; 16:3701-15. [PMID: 19747145 PMCID: PMC2819278 DOI: 10.2174/092986709789105000] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Accepted: 07/27/2009] [Indexed: 12/12/2022]
Abstract
Besides the importance of the renin-angiotensin system (RAS) in the circulation and other organs, the local RAS in the kidney has attracted a great attention in research in last decades. The renal RAS plays an important role in the body fluid homeostasis and long-term cardiovascular regulation. All major components and key enzymes for the establishment of a local RAS as well as two important angiotensin II (Ang II) receptor subtypes, AT1 and AT2 receptors, have been confirmed in the kidney. In additional to renal contribution to the systemic RAS, the intrarenal RAS plays a critical role in the regulation of renal function as well as in the development of kidney disease. Notably, kidney AT1 receptors locating at different cells and compartments inside the kidney are important for normal renal physiological functions and abnormal pathophysiological processes. This mini-review focuses on: 1) the local renal RAS and its receptors, particularly the AT1 receptor and its mechanisms in physiological and pathophysiological processes; and 2) the chemistry of the selective AT1 receptor blocker, losartan, and the potential mechanisms for its actions in the renal RAS-mediated disease.
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Affiliation(s)
- Feichao Xu
- Perinatal Biology Center, Soochow University School of Medicine, Suzhou, People's Republic of China
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23
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Etcheverry SB, Ferrer EG, Naso L, Barrio DA, Lezama L, Rojo T, Williams PAM. Losartan and its interaction with copper(II): Biological effects. Bioorg Med Chem 2007; 15:6418-24. [PMID: 17651974 DOI: 10.1016/j.bmc.2007.06.056] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 06/21/2007] [Accepted: 06/26/2007] [Indexed: 11/28/2022]
Abstract
Losartan, the potassium salt of 2-n-butyl-4-chloro-5-hydroxymethyl-1-[(2'-(1H-tetrazol-5-yl)biphenyl-4-yl)methyl]imidazol, is an efficient antihypertensive drug. The vibrational FTIR and Raman spectra of Losartan (its anionic and protonated forms) are discussed. In addition, the copper(II) complex of Losartan was obtained and characterized as a microcrystalline powder. The metal center is bound to the ligand through the nitrogen atoms of the tetrazolate moiety as determined by vibrational spectroscopy. The compound is a dimer with the metal centers in a tetragonal distorted environment but the presence of a monomeric impurity has been determined by EPR spectroscopy. The antioxidant properties of the complex (superoxide dismutase mimetic activity) and its effect on the proliferation and morphology of two osteoblast-like cells in culture are reported. The new compound exerted more toxic effects on tumoral cells than the copper(II) ion and Losartan.
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Affiliation(s)
- Susana B Etcheverry
- Centro de Química Inorgánica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115 (1900) La Plata, Argentina
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24
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Lamanna C, Catalano A, Carocci A, Di Mola A, Franchini C, Tortorella V, Vanderheyden PML, Sinicropi MS, Watson KA, Sciabola S. AT1 Receptor Ligands: Virtual-Screening-Based Design with TOPP Descriptors, Synthesis, and Biological Evaluation of Pyrrolidine Derivatives. ChemMedChem 2007; 2:1298-310. [PMID: 17628868 DOI: 10.1002/cmdc.200700082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
As a continuing effort to establish the structure-activity relationships (SARs) within the series of the angiotensin II antagonists (sartans), a pharmacophoric model was built by using novel TOPP 3D descriptors. Statistical values were satisfactory (PC4: r(2)=0.96, q(2) ((5) (random) (groups))=0.84; SDEP=0.26) and encouraged the synthesis and consequent biological evaluation of a series of new pyrrolidine derivatives. SAR together with a combined 3D quantitative SAR and high-throughput virtual screening showed that the newly synthesized 1-acyl-N-(biphenyl-4-ylmethyl)pyrrolidine-2-carboxamides may represent an interesting starting point for the design of new antihypertensive agents. In particular, biological tests performed on CHO-hAT(1) cells stably expressing the human AT(1) receptor showed that the length of the acyl chain is crucial for the receptor interaction and that the valeric chain is the optimal one.
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Affiliation(s)
- Claudia Lamanna
- Dipartimento Farmaco-Chimico, Università degli Studi di Bari, Via E. Orabona 4, 70125 Bari, Italy
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25
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Shakya AK, Al-Hiari YM, Alhamami OMO. Liquid chromatographic determination of irbesartan in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 848:245-50. [PMID: 17118719 DOI: 10.1016/j.jchromb.2006.10.044] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 10/19/2006] [Accepted: 10/20/2006] [Indexed: 11/29/2022]
Abstract
A simple and sensitive method was developed for determination of irbesartan by liquid chromatography with fluorescence detection. Irbesartan and losartan (I.S.) in human plasma were extracted using diethyl ether:dichloromethane (7:3, v/v) followed by back extraction with 0.05 M sodium hydroxide. Neutralized samples were analyzed using 0.01 M potassium dihydrogen phosphate buffer (containing 0.07% triethylamine as peak modifier, pH was adjusted with orthophosphoric acid to pH 3.0) and acetonitrile (66:34, v/v). Chromatographic separation was achieved on an ODS-C-18 column (100 mm x 4.6 mm i.d., particle size 5 microm) using isocratic elution (at flow rate 1.25 ml/min). The peak was detected using a fluorescence detector set at Ex 259 nm and Em 385 nm, and the total time for a chromatographic separation was approximately 13 min. The validated quantitation ranges of this method were 15-4000 ng/ml with coefficients of variation between 0.75 and 12.53%. Mean recoveries were 73.3-77.1% with coefficients of variation of 3.7-6.3%. The between- and within-batch precision were 0.4-2.2% and 0.9-6.2%, respectively. The between- and within-batch relative errors (bias) were (-5.5) to 0.9% and (-0.6) to 6.9%, respectively. Stability of irbesartan in plasma was >89%, with no evidence of degradation during sample processing and 60 days storage in a deep freezer at -70 degrees C. This validated method is sensitive and simple with between-batch precision of <3% and can be used for pharmacokinetic studies.
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Affiliation(s)
- Ashok K Shakya
- Department of Medicinal and Pharmaceutical Chemistry, Faculty of Pharmacy and Medical Sciences, Amman University, P.O. Box 263, Amman 19328, Jordan.
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26
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Chopra S, Patil GV, Motwani SK. Release modulating hydrophilic matrix systems of losartan potassium: Optimization of formulation using statistical experimental design. Eur J Pharm Biopharm 2007; 66:73-82. [PMID: 17056238 DOI: 10.1016/j.ejpb.2006.09.001] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Revised: 08/16/2006] [Accepted: 09/05/2006] [Indexed: 11/25/2022]
Abstract
The aim of the present research work was to systemically device a model of factors that would yield an optimized sustained release dosage form of an anti-hypertensive agent, losartan potassium, using response surface methodology by employing a 3-factor, 3-level Box-Behnken statistical design. Independent variables studied were the amount of the release retardant polymers - HPMC K15M (X(1)), HPMC K100M (X(2)) and sodium carboxymethyl cellulose (X(3)). The dependent variables were the burst release in 15 min (Y(1)), cumulative percentage release of drug after 60 min (Y(2)) and hardness (Y(3)) of the tablets with constraints on the Y(2)=31-35%. Statistical validity of the polynomials was established. In vitro release and swelling studies were carried out for the optimized formulation and the data were fitted to kinetic equations. The polynomial mathematical relationship obtained Y(2)=32.91-2.30X(1)-5.69X(2)-0.97X(3)-0.41X(1)X(2)+0.21X(1)X(3)-0.92X(1)(2)-1.89X(2)(2) (r(2)=0.9944) explained the main and quadratic effects, and the interactions of factors influencing the drug release from matrix tablets. The adjusted (0.9842) and predicted values (0.9893) of r(2) for Y(2) were in close agreement. Validation of the optimization study indicated high degree of prognostic ability of response surface methodology. Tablets showed an initial burst release preceding a more gradual sustained release phase following a non-fickian diffusion process. The Box-Behnken experimental design facilitated the formulation and optimization of sustained release hydrophilic matrix systems of losartan potassium.
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Affiliation(s)
- Shruti Chopra
- Department of Pharmaceutics, Faculty of Pharmacy, Hamdard Nagar, New Delhi, India.
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27
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Bienert A, Brzezińiski R, Szałek E, Dubai V, Grześkowiak E, Dyderski S, Drobnik L, Wolc A, Olejniczak-Rabinek M. Bioequivalence study of two losartan formulations administered orally in healthy male volunteers. Arzneimittelforschung 2007; 56:723-8. [PMID: 17220048 DOI: 10.1055/s-0031-1296781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The bioavailability of a new losartan preparation (2-butyl-4-chloro-1-[p-(o-1H-tetrazol-5-ylphenyl)benzyl]imidazole-5-methanol monopotassium salt, CAS 114798-26-4) was compared with the reference preparation of the drug in 24 healthy male volunteers, aged between 19 and 32. The open, randomized, single-blind two-sequence, two-period crossover study design was performed. Under fasting conditions, each subject received a single oral dose of 100 mg losartan as a test or reference formulation. The plasma concentrations of losartan and its active metabolite were analyzed by a rapid and sensitive HPLC method with UV detection. The pharmacokinetic parameters included AUC0-36h, AUC0-infinity, Cmax, t1/2, and Ke. Values of AUC0-infinity demonstrate nearly identical bioavailability of losartan from the examined formulations. The AUC0-infinity of losartan was 2019.92+/-1002.90 and 2028.58+/-837.45 ng x h/ml for the test and reference formulation, respectively. The AUC0-infinity of the metabolite was 10851.52+/-4438.66 and 11041.18 +/-5015.81 ng x h/ml for test and reference formulation, respectively. The maximum plasma concentration (Cmax) of losartan was 745.94+/-419.75 ng/ml for the test and 745.74+/-329.99 ng/ml for the reference product and the Cmax of the metabolite was 1805.77+/-765.39 and 1606.22 +/-977.22 ng/ml for the test and reference product, respectively. No statistical differences were observed for Cmax and the area under the plasma concentration-time curve for both losartan and its active metabolite. 90 % confidence limits calculated for Cmax and AUC from zero to infinity (AUC0-infinity) of losartan and its metabolite were included in the bioequivalence range (0.8-1.25 for AUC). This study shows that the test formulation is bioequivalent to the reference formulation for losartan and its main active metabolite.
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Affiliation(s)
- Agnieszka Bienert
- Department of Clinical Pharmacy and Biopharmacy, Faculty of Pharmacy, Karol Marcinkowski University of Medical Sciences, Poland.
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Tuccinardi T, Calderone V, Rapposelli S, Martinelli A. Proposal of a New Binding Orientation for Non-Peptide AT1 Antagonists: Homology Modeling, Docking and Three-Dimensional Quantitative Structure−Activity Relationship Analysis. J Med Chem 2006; 49:4305-16. [PMID: 16821790 DOI: 10.1021/jm060338p] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A three-dimensional model of the AT1 receptor was constructed by means of a homology modeling procedure, using the X-ray structure of bovine rhodopsin as the initial template and taking into account the available site-directed mutagenesis data. The docking of losartan and its active metabolite EXP3174, followed by 1 ns of molecular dynamics (MD) simulation inserted into the phospholipid bilayer, suggested a different binding orientation for these antagonists from those previously proposed. Furthermore, the docking of several non-peptide antagonists was used as an alignment tool for the development of a three-dimensional quantitative structure-activity relationship (3D-QSAR) model, and the good results confirmed our binding hypothesis and the reliability of the model.
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Affiliation(s)
- Tiziano Tuccinardi
- Dipartimento di Scienze Farmaceutiche, Università di Pisa, via Bonanno 6, 56126 Pisa, Italy
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29
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Seburg RA, Ballard JM, Hwang TL, Sullivan CM. Photosensitized degradation of losartan potassium in an extemporaneous suspension formulation. J Pharm Biomed Anal 2006; 42:411-22. [PMID: 16787732 DOI: 10.1016/j.jpba.2006.04.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2006] [Revised: 04/12/2006] [Accepted: 04/14/2006] [Indexed: 11/20/2022]
Abstract
During development of an extemporaneous suspension formulation for losartan potassium, previously unknown degradation products were observed in experimental suspensions prepared in a commercial cherry syrup vehicle. These degradates increased rapidly when analytical solutions prepared from that suspension were exposed to ambient light. The structures of the degradates were determined using a combination of preparative HPLC, LC/MS, (13)C and (1)H NMR (1D and 2D), and mechanistic chemistry. Each degradate results from destruction of the imidazole ring of losartan. Formation of the two major degradates required exposure to light (UV or visible) and the presence of oxygen. Experiments using Rose Bengal (a singlet oxygen photosensitizer) and 1,4-diazabicyclooctane (DABCO; a singlet oxygen quencher) established that the major photodegradates are formed via the intermediacy of singlet oxygen. The identity of the photosensitizer in the formulation was not unequivocally determined; however, the experiments implicated the artificial flavoring in fulfilling this role.
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Affiliation(s)
- Randal A Seburg
- Pharmaceutical Research & Development, Merck Research Laboratories, P.O. Box 4, West Point, PA 19846, USA.
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30
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Abstract
A tetrazole ring is often used in drug discovery as a replacement for the carboxylic acid group. Previous work indicates that compounds containing a tetrazole moiety show asymmetric permeability in Caco-2 cells characteristic of an efflux transporter substrate. The aim of this study is to determine which transporters are responsible for polarization of transport of tetrazole-containing compounds in Caco-2 cells. Results indicate that only select compounds with tetrazole moieties display asymmetric transport. Three compounds (two commercial drug products and one druglike structure) were selected for further studies. Losartan appears to be primarily a P-glycoprotein (P-gp) substrate, as previously reported, but MRP inhibitors such as MK-571 and rifampicin also affect the difference between apical to basolateral and basolateral to apical transport. Pemirolast and phenyltetrazole derivative C are sensitive to P-gp inhibition, but transport seems to be mediated by one or more of the MRP family of transporters. Additionally, lowering the pH from 7.4 to 4.0 eliminates the polarization of permeability in Caco-2 cells. These studies indicate that some tetrazole compounds are susceptible to efflux, therefore caution should be used when choosing an appropriate functional group to replace carboxylic acids when synthesizing a drug candidate.
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Affiliation(s)
- Amber M Young
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas, USA
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31
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Arayne MS, Sultana N, Haroon U, Qureshi F, Ali SA. In vitro availability of atorvastatin in presence of losartan. Pak J Pharm Sci 2006; 19:134-41. [PMID: 16751125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) are a group of cholesterol lowering agents that have become the largest selling drugs in the world. They are of proven clinical benefit in coronary heart disease, at least in those patients who do not have overt chronic heart failure (CHF). Co-administration of statins with angiotensin II receptor blockers (ARBs) is most common, since there is strong synergy between hypertension and hypercholesterolemia in terms of risk factors for the development of cardiovascular diseases. In present paper, we describe the in vitro availability of atorvastatin, a potent HMG-CoA reductase inhibitor, in presence of losartan potassium, which is a non-peptide angiotensin II receptor antagonist. These studies were carried out at 37, 48 and 60 degrees C in different pH environments simulating human body compartments. It was observed that in pH 1, 7.4 and 9 the availability of atorvastatin was very high while losartan was not at all available. However in pH 4 these effects were reversed and atorvastatin was not available at all. At 48 degrees C the availability of atorvastatin was high and that of losartan was depressed at pH 9, whereas the later was not available at pH 1, 4 and 7.4 at all. Likewise at 60 degrees C, the availability of atorvastatin at pH 7.4 and 9 was high, whereas the charge-transfer complex formed between the two drugs was broken at pH 1 at this temperature and the entire drug was available. On the other hand the availability of losartan at pH 4 and 9 was high while it was not available at pH 1 and 7.4. The availability of atorvastatin was maximum in simulated gastric juice as compared to buffer of pH 7.4 and 9. This high availability of one drug in presence of other is attributed to the formation of a charge-transfer complex, which was stable at elevated temperatures, except at 60 degrees C in pH 1.
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Affiliation(s)
- M Saeed Arayne
- Department of Chemistry, University of Karachi, Karachi-75270, Pakistan.
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32
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Zoumpoulakis P, Politi A, Grdadolnik SG, Matsoukas J, Mavromoustakos T. Structure elucidation and conformational study of V8. J Pharm Biomed Anal 2006; 40:1097-104. [PMID: 16260110 DOI: 10.1016/j.jpba.2005.09.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 09/01/2005] [Accepted: 09/05/2005] [Indexed: 10/25/2022]
Abstract
AT(1) antagonists constitute the most recent class of antihypertensive drugs which act through the Renin Angiotensin System (RAS). In an effort to comprehend their stereoelectronic features, a study was initiated to compare the conformational properties of drugs already marketed for the treatment of hypertension with synthetic ones, possessing common structural characteristics. In this study, the synthetic AT(1) antagonist V8 is structurally elucidated and its conformational properties are studied through a combination of NMR spectroscopy and computational analysis. Its conformational properties are compared with those of the structurally similar prototype AT(1) antagonist losartan.
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33
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Dinç E, Ozdemir A. Linear regression analysis and its application to multivariate chromatographic calibration for the quantitative analysis of two-component mixtures. ACTA ACUST UNITED AC 2005; 60:591-7. [PMID: 15922340 DOI: 10.1016/j.farmac.2005.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 03/07/2005] [Accepted: 04/14/2005] [Indexed: 10/25/2022]
Abstract
Multivariate chromatographic calibration technique was developed for the quantitative analysis of binary mixtures enalapril maleate (EA) and hydrochlorothiazide (HCT) in tablets in the presence of losartan potassium (LST). The mathematical algorithm of multivariate chromatographic calibration technique is based on the use of the linear regression equations constructed using relationship between concentration and peak area at the five-wavelength set. The algorithm of this mathematical calibration model having a simple mathematical content was briefly described. This approach is a powerful mathematical tool for an optimum chromatographic multivariate calibration and elimination of fluctuations coming from instrumental and experimental conditions. This multivariate chromatographic calibration contains reduction of multivariate linear regression functions to univariate data set. The validation of model was carried out by analyzing various synthetic binary mixtures and using the standard addition technique. Developed calibration technique was applied to the analysis of the real pharmaceutical tablets containing EA and HCT. The obtained results were compared with those obtained by classical HPLC method. It was observed that the proposed multivariate chromatographic calibration gives better results than classical HPLC.
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Affiliation(s)
- Erdal Dinç
- Department of Analytical Chemistry, Faculty of Pharmacy, University of Ankara, 06100 Tandoğan, Ankara, Turkey.
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Ansari M, Kazemipour M, Khosravi F, Baradaran M. A comparative study of first-derivative spectrophotometry and high-performance liquid chromatography applied to the determination of losartan potassium in tablets. Chem Pharm Bull (Tokyo) 2005; 52:1166-70. [PMID: 15467227 DOI: 10.1248/cpb.52.1166] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Losartan, a highly effective blood pressure-lowering agent, has been widely used for the treatment of hypertension. A fast and reliable method for the determination of losartan was highly desirable to support formulation screening and quality control. A first-derivative UV spectroscopic method and HPLC were developed for the determination of losartan in the tablet dosage form. The first-derivative spectrum recorded between 220 and 320 nm and a zero-crossing technique for first-derivative measurement at 232.5 nm were selected. The selectivity and sensitivity of the method was in desirable range. In comparison with the direct UV method, first-derivative UV spectroscopy has a definite trough without any interference from UV absorbing-excipients. This method is also fast and economical in comparison with the more time-consuming HPLC method regularly used for formulation screening and quality control and can be used routinely by any laboratory possessing a spectrophotometer with a derivative accessory. The linear concentration ranges were 2-50 microg ml(-1), (D(1)=-0.0159C-0.0056, r=0.9994, n=6). Between-days CV of < or =2.9%, within-day CV of < or =2.1%, and analytical recovery close to 98.1% show the suitability of the method for determination in quality control.
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Affiliation(s)
- Mehdi Ansari
- Department of Pharmaceutics, Faculty of Pharmacy, Kerman Medical Sciences University, Kerman, Iran.
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35
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Lusina M, Cindrić T, Tomaić J, Peko M, Pozaić L, Musulin N. Stability study of losartan/hydrochlorothiazide tablets. Int J Pharm 2004; 291:127-37. [PMID: 15707739 DOI: 10.1016/j.ijpharm.2004.07.050] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2004] [Revised: 06/02/2004] [Accepted: 07/24/2004] [Indexed: 10/26/2022]
Abstract
The purpose of stability testing is to investigate how the quality of a drug product changes with time under the influence of environmental factors, to establish a shelf life for the product and to recommend storage conditions. Stability study of losartan/hydrochlorothiazide tablets is presented in this paper. Losartan (angiotensin II receptor antagonist) and hydrochlorothiazide (diuretic) are successfully used in association in the treatment of hypertension. Stability study of losartan/hydrochlorothiazide tablets consisted of three steps: stress test (forced degradation study), preliminary testing (selection of packaging) and formal stability testing. The results of stress test suggested that losartan/hydrochlorothiazide tablets are sensitive to moisture. It was demonstrated that the developed analytical methods are stability indicating. Additional preliminary testing was performed in order to select appropriate packaging for losartan/hydrochlorothiazide tablets. OPA/Al/PVC//Al blisters were found to provide adequate protection for the product. Based on the first 12 months of the formal stability study, a shelf life of 24 months was proposed. Losartan/hydrochlorothiazide tablets in OPA/Al/PVC//Al blisters are demonstrated to be chemically, physically and microbiologically stable.
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Affiliation(s)
- Maja Lusina
- PLIVA-Research Institute Ltd., Analytics, Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia.
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36
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Mavromoustakos T, Zervou M, Zoumpoulakis P, Kyrikou I, Benetis NP, Polevaya L, Roumelioti P, Giatas N, Zoga A, Minakakis PM, Kolocouris A, Vlahakos D, Grdadolnik SG, Matsoukas J. Conformation and bioactivity. Design and discovery of novel antihypertensive drugs. Curr Top Med Chem 2004; 4:385-401. [PMID: 14965308 DOI: 10.2174/1568026043451302] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peptidomimitism is applied to the medicinal chemistry in order to synthesize drugs that devoid of the disadvantages of peptides. AT1 antagonists constitute a new generation of drugs for the treatment of hypertension designed and synthesized to mimic the C-terminal segment of Angiotensin II and to block its binding action on AT1 receptor. An effort was made to understand the molecular basis of hypertension by studying the conformational analysis of Ang II and its derivatives as well as the AT1 antagonists belonging to SARTANs class of molecules. Such studies offer the possibility to reveal the stereoelectronic factors responsible for bioactivity of AT1 antagonists and to design and synthesize new analogs. An example will be given which proves that drugs with better pharmacological and financial profiles may arise based on this rational design.
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Affiliation(s)
- T Mavromoustakos
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Athens, Greece.
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Mavromoustakos T, Zoumpoulakis P, Kyrikou I, Zoga A, Siapi E, Zervou M, Daliani I, Dimitriou D, Pitsas A, Kamoutsis C, Laggner P. Efforts to understand the molecular basis of hypertension through drug:membrane interactions. Curr Top Med Chem 2004; 4:445-59. [PMID: 14965311 DOI: 10.2174/1568026043451339] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Biological membranes play an essential role in the drug action. They constitute the first barrier for drugs to exert their biological action. AT1 antagonists are amphiphilic molecules and are hypothesized to act on AT1 receptor through incorporation (first step) and lateral diffusion through membrane bilayers (second step). Various biophysical methods along with Molecular Modelling were applied in order to explore the plausible two step proposed mechanism of action for this class of antihypertensive drugs.
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Affiliation(s)
- T Mavromoustakos
- National Hellenic Research Foundation, Institute of Organic and Pharmaceutical Chemistry, Vas. Constantinou 48, 11635 Athens, Greece.
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Zoumpoulakis P, Daliani I, Zervou M, Kyrikou I, Siapi E, Lamprinidis G, Mikros E, Mavromoustakos T. Losartan's molecular basis of interaction with membranes and AT1 receptor. Chem Phys Lipids 2004; 125:13-25. [PMID: 14625072 DOI: 10.1016/s0009-3084(03)00053-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Physicochemical methods were used to study the thermal and dynamic changes caused by losartan in the membrane bilayers. In addition, molecular modeling was implemented to explore its topography both in membranes and AT(1) receptor. Its incorporation resulted in the modification of thermal profile of dipalmitoyl phosphatidylcholine (DPPC) bilayers in a concentration dependent way up to 20mol% as it is depicted from the combination of differential scanning calorimetry (DSC) and MAS data. In particular, the presence of losartan caused lowering of the phase transition temperature and abolishment of the pretransition. T(1) experiments revealed the location of the drug into the membrane bilayers. The use of a combination of biophysical methods along with docking experiments brought out a possible two-step mechanism which involves incorporation of losartan at the interface of membrane bilayers and diffusion in the upper parts of AT(1) receptor helices IV-VII.
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Affiliation(s)
- P Zoumpoulakis
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635, Athens, Greece
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39
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Abstract
Angiotensin II was initially described as a hormone of peripheral origin, the active end product of the Renin-Angiotensin System. The subsequent discovery that Angiotensin II was locally formed and selectively regulated in most organs indicated that tissue Angiotensin II systems might play additional important roles. After initial controversy, the presence of an Angiotensin II system in the brain is now universally accepted. Brain Angiotensin II is probably involved in the regulation of many brain functions. Angiotensin II AT1 receptors are localized not only in areas related to the regulation of autonomic and endocrine control, but also in many other areas of the brain involved in emotional, sensory and motor functions. Angiotensin II AT2 receptors are more abundant in brain areas related to sensory and motor control. The roles of brain Angiotensin II appear to be multiple and complex. In addition to a regulatory role in the control of the autonomic and hormone systems, the peptide participates in brain development, sensory processes, cognition and in the regulation of cerebrovascular flow. Recent developments indicate that blockade of the brain Angiotensin II AT1 receptors not only contributes to a significant blood pressure decrease in hypertension, but that simultaneous antagonism of peripheral and brain AT1 receptors reduces the sympathoadrenal and hormonal responses to stress and prevents stress-induced gastric injury. A novel role emerges for the use of peripheral and centrally acting AT1 receptor antagonists as therapeutically advantageous for the treatment of stress-related disorders.
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Affiliation(s)
- Ines Armando
- Section on Pharmacology, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892-1514, USA.
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40
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Zoumpoulakis P, Zoga A, Roumelioti P, Giatas N, Grdadolnik SG, Iliodromitis E, Vlahakos D, Kremastinos D, Matsoukas JM, Mavromoustakos T. Conformational and biological studies for a pair of novel synthetic AT1 antagonists: stereoelectronic requirements for antihypertensive efficacy. J Pharm Biomed Anal 2003; 31:833-44. [PMID: 12684096 DOI: 10.1016/s0731-7085(02)00655-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
One of the major systems which interferes with the disease of hypertension, is the Renin Angiotensin Aldosterone System (RAS). The octapeptide hormone angiotensin II is the active product of RAS which causes vasoconstriction when binds to the AT(1) receptor. In the last years, there has been a development of drugs which block the Angiotensin II from binding the AT(1) receptor and are called AT(1) antagonists. In an effort to comprehend their stereoelectronic features, a study has been initiated to compare the conformational properties of drugs already marketed for the treatment of hypertension and others which are designed and synthesized in our laboratory possessing structural characteristics necessary for antihypertensive activity. In this study, two synthetic non-peptide AT(1) antagonists, are structurally elucidated and their conformational properties and bioactivity are compared to the prototype and first approved drug of this category in the market; losartan (trade name: COZAAR).
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Affiliation(s)
- P Zoumpoulakis
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas Constantinou 48, 11635, Athens, Greece
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41
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Abstract
Chemical feature based pharmacophore models were elaborated for angiotensin II receptor subtype 1 (AT(1)) antagonists using both a quantitative and a qualitative approach (Catalyst HypoGen and HipHop algorithms, respectively). The training sets for quantitative model generation consisted of 25 selective AT(1) antagonists exhibiting IC(50) values ranging from 1.3 nM to 150 microM. Additionally, a qualitative pharmacophore hypothesis was derived from multiconformational structure models of the two highly active AT(1) antagonists 4u (IC(50) = 0.2 nM) and 3k (IC(50) = 0.7 nM). In the case of the quantitative model, the best pharmacophore hypothesis consisted of a five-features model (Hypo1: seven points, one hydrophobic aromatic, one hydrophobic aliphatic, a hydrogen bond acceptor, a negative ionizable function, and an aromatic plane function). The best qualitative model consisted of seven features (Hypo2: 11 points, two aromatic rings, two hydrogen bond acceptors, a negative ionizable function, and two hydrophobic functions). The obtained pharmacophore models were validated on a wide set of test molecules. They were shown to be able to identify a range of highly potent AT(1) antagonists, among those a number of recently launched drugs and some candidates presently undergoing clinical tests and/or development phases. The results of our study provide confidence for the utility of the selected chemical feature based pharmacophore models to retrieve structurally diverse compounds with desired biological activity by virtual screening.
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Affiliation(s)
- Eva M Krovat
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria.
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42
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Abstract
[reaction: see text] Chemoselective alcohol oxidations using catalytic TEMPO and stoichiometric iodine as the terminal oxidant were studied. Iodine was compared to other positive halogens as the terminal oxidant and shown to be superior in cases of electron-rich and heteroaromatic rings. The new conditions were successfully applied to an important intermediate (2) in the synthesis of Losartan.
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Affiliation(s)
- Ross A Miller
- Merck Research Laboratories, PO Box 2000, Rahway, New Jersey 07065, USA.
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43
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Hertzog DL, McCafferty JF, Fang X, Tyrrell RJ, Reed RA. Development and validation of a stability-indicating HPLC method for the simultaneous determination of losartan potassium, hydrochlorothiazide, and their degradation products. J Pharm Biomed Anal 2002; 30:747-60. [PMID: 12367701 DOI: 10.1016/s0731-7085(02)00385-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Losartan potassium was the first in a new class of potent angiotensin II receptor antagonists which are well-tolerated in the treatment of hypertension. Losartan potassium is the active ingredient in tablets COZAAR and is combined with diuretic co-active hydrochlorothiazide (HCTZ) in tablets HYZAAR for increased efficacy. Losartan potassium has one main impurity and two primary degradates. HCTZ has one major degradate as well as two common process impurities. Historically, separate methods have been used for the analysis of each active and their respective impurities and degradates. The ultimate goal of this work was to develop and validate a single high-performance liquid chromatography method selective for the eight main components of tablets HYZAAR. A single method was developed to afford simultaneous quantitation of actives and degradates for each of the two existing formulations. Each method is presented herein and demonstrated to be suitable for quantitation to 0.1% levels of all relevant degradates, as well as 100% levels of respective drug substances.
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Affiliation(s)
- Deanne L Hertzog
- North American Stability Unit, Merck & Co, Inc, WP 38B-3, West Point, PA 19486, USA.
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44
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Fernández D, Vega D, Ellena JA, Echeverría G. Losartan potassium, a non-peptide agent for the treatment of arterial hypertension. Acta Crystallogr C 2002; 58:m418-20. [PMID: 12094046 DOI: 10.1107/s0108270102009745] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2002] [Accepted: 05/30/2002] [Indexed: 11/10/2022] Open
Abstract
In the title compound, potassium 2-butyl-4-chloro-1-[[2'-(5-tetrazolido)biphenyl-4-yl]methyl]-1H-imidazol-5-ylmethanol, K(+) x C(22)H(22)ClN(6)O(-), the imidazole and tetrazole rings are at angles of 85.0 (2) and 51.8 (1) degrees, respectively, to the phenyl rings to which they are attached, while the dihedral angle between the latter two rings is 46.7 (1) degrees. The coordination sphere of the metal cation consists of six tetrazoyl N atoms, the methanol O atom and the pi cloud of one of the phenyl rings. These interactions determine the formation of columns of molecular anions that lie parallel to the b axis, while hydrogen bonding contributes to intercolumnar cohesion. Far from the centre of the columns, the hydrocarbon chain is immersed in a hydrophobic environment.
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Affiliation(s)
- Daniel Fernández
- Escuela de Ciencia y Tecnología, Universidad Nacional de General San Martín, Calle 91 3391, 1653 Villa Ballester, Buenos Aires, Argentina.
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Krämer C, Sunkomat J, Witte J, Luchtefeld M, Walden M, Schmidt B, Tsikas D, Böger RH, Forssmann WG, Drexler H, Schieffer B. Angiotensin II receptor-independent antiinflammatory and antiaggregatory properties of losartan: role of the active metabolite EXP3179. Circ Res 2002; 90:770-6. [PMID: 11964369 DOI: 10.1161/01.res.0000014434.48463.35] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiotensin II (Ang II) type 1 receptor (AT(1)) antagonists such as losartan (LOS) are widely used for the treatment of hypertension and elicit antiinflammatory and antiaggregatory in vitro and in patients, although the underlying mechanism are unclear. Following computer-based molecule similarity, we proposed that on cytochrome-P450 degradation, the LOS metabolite EXP3179 is generated, which shows molecule homology to indomethacin, a cyclooxygenase inhibitor with antiinflammatory and antiaggregatory properties. Subsequently, serum-levels of EXP3179 were determined for 8 hours in patients receiving a single oral dose of 100 mg LOS. High-performance liquid chromatography followed by liquid chromatography-mass spectrometry (GC-MS) [corrected] from serum samples revealed a maximum of 10(-7) mol/L for EXP3179 peaking between 3 to 4 hours. The increase in serum-EXP3179 levels was associated with a significant reduction in platelet aggregation in vivo (-35+/-4%, P<0.001 versus control). EXP3179 generation was investigated in a chemical reaction mimicking the liver cytochrome-P450-dependent LOS-degradation and human endothelial cells were exposed to Ang II or lipopolysaccharides (LPS) in the presence of EXP3179 (10(-7) mol/L). LPS- and Ang II-induced COX-2 transcription was abolished by EXP3179. Moreover, EXP3179 significantly reduced Ang II- and LPS-induced formation of prostaglandin F2alpha as determined by GC-MS [corrected]. Thus, antiinflammatory properties of LOS are mediated via its EXP3179 metabolite by abolishing COX-2 mRNA upregulation and COX-dependent TXA2 and PGF2alpha generation. Serum levels of EXP3179 are detectable in patients in concentrations that exhibit antiinflammatory and antiaggregatory properties in vitro.
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Affiliation(s)
- Christine Krämer
- Department of Cardiology, Medizinische Hochschule Hannover, Germany
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46
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Polevaya L, Mavromoustakos T, Zoumboulakis P, Golic Grdadolnik S, Roumelioti P, Giatas N, Mutule I, Keivish T, Vlahakos DV, Iliodromitis EK, Kremastinos DT, Matsoukas J. Synthesis and study of a cyclic angiotensin II antagonist analogue reveals the role of pi*--pi* interactions in the C-terminal aromatic residue for agonist activity and its structure resemblance with AT(1) non-peptide antagonists. Bioorg Med Chem 2001; 9:1639-47. [PMID: 11408184 DOI: 10.1016/s0968-0896(01)00059-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The novel amide linked Angiotensin II (ANG II) cyclic analogue cyclo(3, 5) -[Sar(1)-Lys(3)-Glu(5)-Ile(8)] ANG II (18) has been designed, synthesized and bioassayed in anesthetized rabbits. The constrained cyclic analogue with a lactam amide bridge linking a Lys-Glu pair at positions 3 and 5 and possessing Ile at position 8, was synthesized by solution procedure using the maximum protection strategy. This analogue was found to be inhibitor of Angiotensin II. NMR spectroscopy coupled with computational analysis showed clustering between the side chains of the key aminoacids Tyr(4)-His(6)-Ile(8) similar to that observed with ANG II. The obtained data show that only pi*--pi* interactions observed in ANG II or its superagonist Sar(1) [ANG II] are missing. Therefore, it can be concluded that these interactions are essential for agonist activity. Conformational analysis comparisons between AT(1) antagonists losartan, eprosartan and irbesartan with C-terminal segment of cyclic compound 18 revealed structural similarities.
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Affiliation(s)
- L Polevaya
- Laboratory of Peptide Chemistry, Latvian Institute of Organic Synthesis, Riga, LV-1006, Latvia
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47
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Bravo R, Somoza B, Ruiz-Gayo M, González C, Ruilope LM, Fernández-Alfonso MS. Differential Effect of Chronic Antihypertensive Treatment on Vascular Smooth Muscle Cell Phenotype in Spontaneously Hypertensive Rats. Hypertension 2001; 37:E4-E10. [PMID: 11358952 DOI: 10.1161/01.hyp.37.5.e4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
—The aim of this study was to investigate the effect of chronic losartan or captopril on vascular smooth muscle cell (VSMC) phenotype and vascular function in spontaneously hypertensive rats. Male 12-week-old rats were treated for 16 weeks with losartan (15 mg/kg per day) or captopril (60 mg/kg per day) in their drinking water. Systolic blood pressure, measured by the tail-cuff method, was reduced ≈40 mm Hg in both treatment groups compared with a nontreated control group. Cell structure and proliferation studies were performed in VSMCs obtained from rat carotid arteries. Cells from the losartan-treated group showed a significant reduction in size, total protein content, and nucleus number, as well as proliferation after stimulation with 10% fetal calf serum and an increased percentage of cells in the G
1
phase compared with the control and captopril-treated groups. Functional studies were performed in isolated carotid arteries from these groups. Contractions elicited by 75 mmol/L KCl or 10
−
7
mol/L norepinephrine and relaxations elicited by acetylcholine were similar in all groups. Concentration-response curves to angiotensin I or angiotensin II (10
−
10
to 3×10
−
7
mol/L) were almost abolished in the losartan-treated group and were not modified by preincubation with the angiotensin type 2 receptor antagonist PD 123,319. These results suggest that long-term losartan treatment significantly changes VSMC phenotype and proliferative status, apparently unrelated to blood pressure lowering or to endothelial function improvements.
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Affiliation(s)
- R Bravo
- Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense de Madrid
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48
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Yeung PK, Jamieson A, Smith GJ, Fice D, Pollak PT. Determination of plasma concentrations of losartan in patients by HPLC using solid phase extraction and UV detection. Int J Pharm 2000; 204:17-22. [PMID: 11011981 DOI: 10.1016/s0378-5173(00)00453-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To establish a HPLC assay for plasma losartan and its active metabolite EXP3174 to facilitate clinical pharmacokinetic studies. METHODS the HPLC system consisted of a 250 x 2 mm i.d. C18 reversed phase column preceded by a 4 x 4 mm guard column, a UV detector set at 254 nm, and an integrator. The mobile phase was a mixture of 0.01 M ammonium phosphate: acetonitrile: methanol (6:3:1) containing 0.02 % sodium azide and 0.04% TEA, with pH adjusted to 3.2. The system was operated isocratically at ambient temperature at a flow rate of 0.3 ml/min. Losartan and its active metabolite EXP3174 were extracted from plasma using C2 bonded silica gel standard solid phase extraction. RESULTS recoveries of losartan and EXP3174 from plasma were greater than 70%. Using 0.5 ml of plasma sample, standard curves were linear from 10 to 300 ng/ml (r2 = 0.996 and 0.997 for losartan and EXP 3174, respectively). Sensitivity of the assay was < 10 ng/ml. Intra-and inter-assay variations were < 10 and 15%. respectively. The assay has been successfully applied to measuring plasma concentrations of losartan and EXP3174 in patients receiving a daily dose of losartan (50-100 mg). CONCLUSION The HPLC assay has adequate sensitivity, reproducibility, and specificity for clinical pharmacokinetic studies.
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Affiliation(s)
- P K Yeung
- Pharmacokinetics and Metabolism Laboratory, College of Pharmacy, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada.
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Abstract
Several angiotensin II receptor blockers (ARB) are currently available for the treatment of hypertension. These drugs share a common mechanism of action-antagonism of angiotensin II AT1 receptors; however, their receptor binding kinetics differ. Candesartan has a higher affinity for the AT1 receptor than all the other ARB. In addition, candesartan and irbesartan block the AT1 receptor with insurmountable antagonism, whereas losartan, valsartan, and eprosartan are competitive antagonists. The pharmacokinetics of these ARB also differ in terms of oral bioavailability, rate of absorption, metabolism, and route and rate of elimination. Both losartan potassium and candesartan cilexetil are prodrugs; however, losartan is partially converted into EXP3174 in the liver, whereas candesartan cilexetil is converted completely into candesartan during gastrointestinal absorption. On the basis of elimination half-lives, losartan, valsartan, and eprosartan may be classified as shorter acting and candesartan cilexetil and irbesartan as longer acting. Each drug effectively lowers blood pressure during once daily administration to patients with mild to moderate hypertension, with candesartan cilexetil requiring the lowest dosage and providing dose-dependent efficacy. Initial comparative clinical trials suggest that both candesartan cilexetil and irbesartan in the doses used are significantly more effective than losartan in lowering trough sitting diastolic blood pressure. It remains to be determined, however, whether the observed pharmacologic and pharmacokinetic differences among the members of the ARB class will have a clinically significant impact on long-term cardiovascular outcomes and reductions of cardiovascular mortality.
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Affiliation(s)
- S Oparil
- University of Alabama at Birmingham, USA
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50
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Theodoropoulou E, Marsh D. Interactions of angiotensin II non-peptide AT(1) antagonist losartan with phospholipid membranes studied by combined use of differential scanning calorimetry and electron spin resonance spectroscopy. Biochim Biophys Acta 1999; 1461:135-46. [PMID: 10556495 DOI: 10.1016/s0005-2736(99)00155-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We used differential scanning calorimetry (DSC) and electron spin resonance (ESR) spectroscopy to investigate the interactions of Losartan, a potent, orally active Angiotensin II AT(1) receptor antagonist with phospholipid membranes. DSC results showed that Losartan sensitively affected the chain-melting behavior of dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC) bilayer membranes. ESR spectroscopy showed that phosphatidylcholines spin-labeled at the 5-position of the sn-2 acyl chain (n-PCSL with n=5), incorporated either in DMPC or DPPC bilayers containing Losartan, were restricted in motion both in the gel and in the liquid-crystalline membrane phases, indicating a location of the antagonist close to the interfacial region of the phosphatidylcholine bilayer. At high drug concentrations (mole fraction >/= x=0.60), the decrease in chain mobility registered by 5-PCSL in fluid-phase membranes is smaller than that found at lower concentrations, whereas that registered by 14-PCSL is further increased. This indicates a different mode of interaction with Losartan at high concentrations, possibly arising from a location deeper within the bilayer. Additionally, Losartan reduced the spin-spin broadening of 12-PCSL spin labels in the gel-phase of DMPC and DPPC bilayers. As a conclusion, our study has shown that Losartan interacts with phospholipid membranes by affecting both their thermotropic behavior and molecular mobility.
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Affiliation(s)
- E Theodoropoulou
- Abteilung Spektroskopie und Photochemische Kinetik, Max-Planck Institut für Biophysikalische Chemie, Am Fassberg 11, D-37077, Göttingen, Germany.
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