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Development of a novel ion-pairing UPLC method with cation-exchange solid-phase extraction for determination of free timolol in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1096:228-235. [DOI: 10.1016/j.jchromb.2018.08.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 07/16/2018] [Accepted: 08/19/2018] [Indexed: 01/08/2023]
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2
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Simultaneous determination of timolol maleate in combination with some other anti-glaucoma drugs in rabbit aqueous humor by high performance liquid chromatography–tandem mass spectroscopy. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1022:109-117. [DOI: 10.1016/j.jchromb.2016.04.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 11/22/2022]
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3
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Lotfy HM, Hegazy MA, Rezk MR, Omran YR. Novel spectrophotometric methods for simultaneous determination of timolol and dorzolamide in their binary mixture. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 126:197-207. [PMID: 24607469 DOI: 10.1016/j.saa.2014.02.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/30/2014] [Accepted: 02/02/2014] [Indexed: 06/03/2023]
Abstract
Two smart and novel spectrophotometric methods namely; absorbance subtraction (AS) and amplitude modulation (AM) were developed and validated for the determination of a binary mixture of timolol maleate (TIM) and dorzolamide hydrochloride (DOR) in presence of benzalkonium chloride without prior separation, using unified regression equation. Additionally, simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of the binary mixture namely; simultaneous ratio subtraction (SRS), ratio difference (RD), ratio subtraction (RS) coupled with extended ratio subtraction (EXRS), constant multiplication method (CM) and mean centering of ratio spectra (MCR). The proposed spectrophotometric procedures do not require any separation steps. Accuracy, precision and linearity ranges of the proposed methods were determined and the specificity was assessed by analyzing synthetic mixtures of both drugs. They were applied to their pharmaceutical formulation and the results obtained were statistically compared to that of a reported spectrophotometric method. The statistical comparison showed that there is no significant difference between the proposed methods and the reported one regarding both accuracy and precision.
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Affiliation(s)
- Hayam Mahmoud Lotfy
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt.
| | - Maha A Hegazy
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt
| | - Mamdouh R Rezk
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt
| | - Yasmin Rostom Omran
- Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt
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4
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Ahmed IS, Hassan MA, Kondo T. Effect of lyophilized grapefruit juice on P-glycoprotein-mediated drug transport in-vitro and in-vivo. Drug Dev Ind Pharm 2013; 41:375-81. [PMID: 24303901 DOI: 10.3109/03639045.2013.866141] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The administration of grapefruit juice (GFJ) has been postulated to inhibit the activity of P-glycoprotein (P-gp) transport system and thus can enhance the uptake of substrate drugs. However, for various reasons, the results obtained have been always swaying between confirmation and refutation. This study aims at re-evaluating the effect of lyophilized freshly-prepared grapefruit juice (LGFJ) prepared from the whole peeled fruit on P-gp activity using the model drug doxorubicin (DOX) in-vitro and timolol maleate (TM) in-vivo. Human uterine sarcoma MES-SA/DX5v cells, grown under nanomolar concentration of DOX and highly expressing P-gp, were used as model cells for in-vitro studies whereas white New Zealand male rabbits were used for in-vivo studies. Results showed that the accumulation of DOX in MES-SA/DX5v cells was increased by 18.3 ± 2.0% in presence of LGFJ compared to control experiments. Results from in-vivo absorption studies showed that the relative oral bioavailability of TM ingested with LGFJ was significantly higher by 70% and 43% compared to the oral bioavailability of TM ingested with saline and a commercial GFJ, respectively. This study as such confirms the inhibitory effects of LGFJ on P-gp efflux proteins and highlights the superiority of using lyophilized freshly prepared juices over the commercially available juices in research studies. Also, the results call for further studies to assess the possibility of co-administrating LGFJ with anti-cancer agents to modulate multidrug resistance in their cellular environment or incorporating LGFJ in solid dosage forms to improve oral bioavailability of drugs.
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Affiliation(s)
- Iman S Ahmed
- Department of Pharmaceutics & Pharmaceutical Technology, College of Pharmacy, University of Sharjah , Sharjah , United Arab Emirates
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5
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Novel transdermal delivery of Timolol maleate using sugar esters: Preclinical and clinical studies. Eur J Pharm Biopharm 2009; 72:239-45. [DOI: 10.1016/j.ejpb.2008.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 11/21/2008] [Accepted: 12/05/2008] [Indexed: 11/17/2022]
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6
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Marini RD, Servais AC, Rozet E, Chiap P, Boulanger B, Rudaz S, Crommen J, Hubert P, Fillet M. Nonaqueous capillary electrophoresis method for the enantiomeric purity determination of S-timolol using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin: validation using the accuracy profile strategy and estimation of uncertainty. J Chromatogr A 2006; 1120:102-11. [PMID: 16643932 DOI: 10.1016/j.chroma.2006.03.104] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2005] [Revised: 03/10/2006] [Accepted: 03/21/2006] [Indexed: 11/23/2022]
Abstract
Nonaqueous capillary electrophoresis (NACE) was successfully applied to the enantiomeric purity determination of S-timolol maleate using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin (HDMS-beta-CD) as chiral selector. With a background electrolyte made up of a methanolic solution of 0.75 M formic acid, 30 mM potassium camphorsulfonate and containing 30 mM HDMS-beta-CD, the determination of 0.1% of R-timolol in S-timolol could be performed with an enantiomeric resolution of 8.5. Pyridoxine was selected as internal standard. The NACE method was then fully validated by applying a novel strategy using accuracy profiles. It is based on beta-expectation tolerance intervals for the total measurement error which includes trueness and intermediate precision. The uncertainty of measurements derived from beta-expectation tolerance intervals was estimated at each concentration level of the validation standards. To confirm the suitability of the developed and validated method, several real samples of S-timolol maleate containing R-timolol maleate at different concentrations were analysed and the results were compared to those obtained by liquid chromatography.
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Affiliation(s)
- Roland Djang'eing'a Marini
- Laboratory of Analytical Chemistry, Bioanalytical Chemistry Research Unit, Institute of Pharmacy, University of Liège, CHU, B36, B-4000 Liège 1, Belgium
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7
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Chromatographic Determination of Drugs and Their Metabolites for Phenotyping Cytochrome P-450 Isoenzymes. Pharm Chem J 2005. [DOI: 10.1007/s11094-005-0095-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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8
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Conjeevaram R, Chaturvedula A, Betageri GV, Sunkara G, Banga AK. Iontophoretic in vivo transdermal delivery of beta-blockers in hairless rats and reduced skin irritation by liposomal formulation. Pharm Res 2004; 20:1496-501. [PMID: 14567646 DOI: 10.1023/a:1025726715063] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To demonstrate the in vivo transdermal delivery and establish the comparative pharmacokinetics of five beta-blockers in hairless rat. METHODS Intravenous dosing was initially done via jugular cannula. For iontophoretic delivery, current (0.1 mA/cm2) was applied for 2 h through a drug reservoir patch containing the beta-blocker (10 mg/ml). Blood samples were collected and analyzed by stereoselective HPLC assays. Any irritation resulting from patch application was quantified by a chromameter. Multilamellar liposomal formulation was prepared by the thin-film hydration method and converted to unilamellar liposomes by extrusion. RESULTS With transdermal iontophoresis, therapeutically relevant amounts of propranolol (83.78 +/- 7.4 ng/ml) were delivered within an hour and lasted for up to 4 h. Cmax (185.1 +/- 56.8 ng/ml) was reached at hour 3. A significantly higher amount (p < 0.05) of sotalol HCl was delivered compared to other beta-blockers. There was no significant difference in the S/R ratio of AUC0-t for enantiomers after both intravenous and transdermal delivery. Skin irritation was significantly reduced (p < 0.05) when a liposomal formulation of the propranolol base was used rather than the base itself. CONCLUSIONS The comparative pharmacokinetics of intravenous and transdermal iontophoretic delivery of five beta-blockers in hairless rats was established. It was shown that there is no stereoselective permeation.
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Affiliation(s)
- Rajkumar Conjeevaram
- Department of Pharmaceutical Sciences, School of Pharmacy, Mercer University, Atlanta, Georgia 30341-4155, USA
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9
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Djang'eing'a Marini R, Chiap P, Boulanger B, Dewe W, Hubert P, Crommen J. LC method for the simultaneous determination ofR-timolol and other closely related impurities inS-timolol maleate: Optimization by use of an experimental design. J Sep Sci 2003. [DOI: 10.1002/jssc.200301367] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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Erk N. Simultaneous determination of dorzolamide HCL and timolol maleate in eye drops by two different spectroscopic methods. J Pharm Biomed Anal 2002; 28:391-7. [PMID: 11929684 DOI: 10.1016/s0731-7085(01)00627-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two-component mixtures of dorzolamide hydrochloride and timolol maleate were assayed by first derivative and ratio derivative spectrophotometric methods. The first method, derivative spectrophotometry, by the zero-crossing measurements, was used due to the drugs closely overlapping absorption spectra. Linear calibration graphs of first derivative values at 250.3 nm for dorzolamide hydrochloride and 315.8 nm for timolol maleate. The second method, is based on ratio first derivative spectrophotometry, the amplitudes in the first derivative of the ratio spectra at 242.9 and at 223.5 nm were selected to determine dorzolamide and timolol maleate in the binary mixture. Calibration graphs were established for 8.0-30.0 microg ml(-1) for dorzolamide hydrochloride and 3.0-24.6 microg ml(-1) for timolol maleate in binary mixture. Good linearity, precision and selectivity were found, and the proposed methods were applied successfully to the pharmaceutical dosage from containing the above-mentioned drug combination without any interference by the excipients. Vierordt's method was also developed for a comparison method.
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Affiliation(s)
- Nevin Erk
- Department of Analytical Chemistry, Faculty of Pharmacy, University of Ankara, 06100 Ankara, Turkey.
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Kulkarni SP, Amin PD. Stability indicating HPTLC determination of timolol maleate as bulk drug and in pharmaceutical preparations. J Pharm Biomed Anal 2000; 23:983-7. [PMID: 11095299 DOI: 10.1016/s0731-7085(00)00389-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Timolol was the first beta blocker to be used as an anti-glaucoma agent and to date remains as the standard because none of the newer beta blockers were found to be more effective. The high performance thin layer chromatographic method of analysis of timolol maleate is reported. The mobile phase selected was ethyl acetate-methanol-isopropyl alcohol-ammonia (25%) (80:20:2:1, v/v/v/v). The calibration curve of the drug was linear in the range of 100-600 ng. The spectrodensitometric analysis was carried out at 294 nm. The mean (+/- RSD) values of slope, correlation coefficient and intercept were 2487.5 (+/- 0.9), 0.996 (+/- 0.081) and 90463 (+/- 1.1), respectively. The system precision and the method precision were excellent with an RSD of 2.8 and 1.004, respectively. The limits of detection and quantitation were 10 and 40 ng, respectively. The mean percent recovery was found to be 98.6. Timolol maleate was degraded by exposing the drug to heat, acid and base. The degraded products were found to be well separated from the pure drug with significantly different Rf values suggesting a stability indicating analysis method for quantification of timolol maleate in pharmaceutical preparations and as bulk drug. The method was utilized to analyze timolol maleate from conventional eye drops and novel sustained release solid polymeric ocular inserts and oral preparations. The reported method is simple, selective, precise, accurate, time saving and economic as compared to reported HPLC methods.
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Affiliation(s)
- S P Kulkarni
- University Department of Chemical Technology (Autonomous), University of Mumbai, Matunga, India
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12
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He H, Edeki TI, Wood AJ. Determination of low plasma timolol concentrations following topical application of timolol eye drops in humans by high-performance liquid chromatography with electrochemical detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1994; 661:351-6. [PMID: 7894678 DOI: 10.1016/0378-4347(94)00357-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A simple and sensitive high-performance liquid chromatographic assay was developed for determination of timolol in human plasma following administration of two drops of a 5% timolol ophthalmic solution. A 4% butyl alcohol-hexane extract of an alkalized sample of plasma was chromatographed on a reversed-phase column and the components in the column effluent were monitored by coulometric detection. The extraction efficiency of timolol was 69.02 +/- 4.16% (mean +/- S.D.) and its detection limit was 107.2 pg/ml. The effect of mobile phase pH, buffer concentration and the working potential of the detector on column performance and the electrochemical response are described.
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Affiliation(s)
- H He
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232-6620
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13
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Kubota K, Yamada T, Kikuchi K, Koyama E, Ishizaki T. Pharmacokinetics and beta-blocking effects of transdermal timolol. Eur J Clin Pharmacol 1993; 44:493-5. [PMID: 8359190 DOI: 10.1007/bf00315551] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The pharmacokinetic profiles of transdermal timolol 6 and 24 mg (as 5 and 20% w/v patches) was studied in four healthy young volunteers. To assess its bioavailability, the pharmacokinetics of an IV infusion of timolol maleate 5 mg was also determined in the same subjects. When the 20% (w/v) timolol patch was applied, the mean bioavailability was 74.4%. Plasma timolol concentrations were below the detection limit when a 5% patch was applied to the same skin area in all four subjects, except for one in whom the bioavailability was 23.6%. Weak erythema developed at the application site in all of the volunteers after application of the 20% (w/v) patch. However, erythema did not develop in any volunteer when the 5% patch was applied. The beta-blocking effect was determined by exercise testing. Similar plasma levels generated similar changes in exercise-induced heart rate after the transdermal and intravenous administration of timolol.
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Affiliation(s)
- K Kubota
- Division of Clinical Pharmacology, National Medical Centre, Tokyo, Japan
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14
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Olah TV, Gilbert JD, Barrish A. Determination of the beta-adrenergic blocker timolol in plasma by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. J Pharm Biomed Anal 1993; 11:157-63. [PMID: 8504187 DOI: 10.1016/0731-7085(93)80136-o] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A method based on LC-MS-MS has been developed for the determination of timolol in plasma using the (CD3)3-labelled species as the internal standard. Timolol is isolated from plasma by a simple solid-phase extraction and converted to its oxazolidin-2-one prior to analysis on a 50 x 4.6 mm reversed-phase high-performance liquid chromatography column packed with SynChropak, C18, 5 microns. The column eluate is passed by means of a heated nebulizer interface into a corona discharge atmospheric pressure chemical ionization source where the analyte and its internal standard are detected using multiple reaction monitoring (MRM). The very high specificity of this technique permits chromatographic run times of less than 2 min. The method has a lower quantifiable limit of 0.5 ng ml-1, with intra- and inter-day relative standard deviations less than 10%, and enables the determination of timolol in plasma after ocular administration to volunteers.
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Affiliation(s)
- T V Olah
- Merck Research Laboratories, West Point, PA 19486
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15
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Sutton BM, Richardson RA. Assay of timolol in human plasma using gas chromatography with electron-capture detection. JOURNAL OF CHROMATOGRAPHY 1992; 581:277-80. [PMID: 1452619 DOI: 10.1016/0378-4347(92)80282-u] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A simple and sensitive gas chromatographic method has been developed for the determination of timolol in plasma using electron-capture detection and propranolol as internal standard. Timolol was extracted using butyl chloride and derivatized using trifluoroacetic anhydride in butyl acetate. The lower detection limit for the assay was found to be 1 ng/ml from 1 ml of plasma. Extracted standards gave within-day precision of 12.55, 9.68 and 3.78% for 1, 20 and 100 ng/ml plasma samples, respectively. A recovery of at least 80% of timolol was found using the extraction method described. The assay was used in a randomized cross-over bioequivalence trial using an oral administration of 20 mg of timolol. Pharmacokinetic parameters compare favourably with other literature values.
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Affiliation(s)
- B M Sutton
- Pharmaceuticals and Toxicology Section, DSIR Chemistry, Petone, New Zealand
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