1
|
Hamad AA, Saleh SF, Mahdi WA, Alshehri S, Hamd MAE. Facile Integration of Hanztsch's Switch-Off/On Modeled Fluorogenic Probe for Feasible Tagging and Tracking of the Midodrine Drug in Different Matrices; First Evaluation of the Method's Greenness, Whiteness, Blueness, Quantum Yield, and Tablets' Content Homogeneity. J Fluoresc 2024:10.1007/s10895-024-03839-x. [PMID: 39102112 DOI: 10.1007/s10895-024-03839-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Accepted: 07/03/2024] [Indexed: 08/06/2024]
Abstract
The proposed investigation follows a certain methodology to guarantee that the procedure employed is sustainable and green. It is noteworthy to mention that various tools have been implemented as potential indicators of environmental sustainability (greenness and whiteness). From a novelty viewpoint, a new tool, BAGI, for the method's blueness evaluation was applied to the planned method and showed a high applicability score. Fortunately, the WAC concept, which combines ecological and functional variables using the Green/Red/Blue design (RBG 12 tool), identifies the established analytical approach as white. In the planned study, a new, green, simple, nano-trace-sensitive, original fluorimetric methodology was established to analyze and assess midodrine hydrochloride content in different matrices. Midodrine's primary amine moiety reacts with Diacetylmethane/Oxymethylene reagent in an acetate buffer, which leads to generating a fluorescent dihydrolutidine derivative (Hantzsch-named reaction). Consequently, the signal strength of this compound was quantified at 487 nm, with an excitation wavelength of 426 nm. This analysis indicated that the technique exhibited linearity within the range of 0.05 to 1.1 µg mL-1 concentrations, accompanied by remarkably good sensitivity values (LOD and LOQ). The methodology employed in this examination was subjected to validation following the rules recognized by ICH. From the perspective of pharmacy and chemistry, the method presented in this study was successfully employed to analyze commercially available tablets, oral drops, and human fluids. The outcomes obtained demonstrated satisfactory recovery rates without any interference from excipients. Following the USP recommendations, the intended technique was finally implemented to explore the content homogeneity evaluation.
Collapse
Affiliation(s)
- Ahmed Abdulhafez Hamad
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut, 71524, Egypt.
| | - Safaa F Saleh
- Pharmaceutical Chemistry Department, College of Pharmacy, Jazan University, 45142, Jazan, Saudi Arabia
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Fayoum University, Fayoum, 63514, Egypt
| | - Wael A Mahdi
- Department of Pharmaceutics, College of Pharmacy, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Sultan Alshehri
- Department of Pharmaceutics, College of Pharmacy, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Mohamed A El Hamd
- Department of Pharmaceutical Chemistry, College of Pharmacy, Shaqra University, Shaqra, 11961, Saudi Arabia.
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, South Valley University, Qena, 83523, Egypt.
| |
Collapse
|
2
|
Derayea SM, Abdelgaleel M, Nagi DM, Oraby M, Khashaba PY. Utility of dansyl chloride for the establishment of a sensitive spectrofluorimetric approach for estimating midodrine hydrochloride: application to content uniformity testing. RSC Adv 2023; 13:33453-33458. [PMID: 38025857 PMCID: PMC10644863 DOI: 10.1039/d3ra06268f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
A new, straightforward spectrofluorimetric approach with high sensitivity was established for determining midodrine hydrochloride based on derivatizing this drug through its reaction with 5-(dimethylamino)naphthalene-1-sulfonyl chloride (dansyl chloride). The highly fluorescent product was extracted with methylene chloride, and then its emission was measured at 532 nm after excitation at 339 nm. The reaction was conducted in aqueous medium containing 0.1 M borate buffer (pH 8.2). The results showed that the proposed method is sensitive with high linearity in the range from 0.1 to 3 μg mL-1. The lower limits of detection and quantitation were 29 and 88 ng mL-1, respectively. Furthermore, the proposed approach was analytically assessed by applying the ICH guidelines. The suggested approach was effectively utilized for the estimation of the medicine in its marketable tablet formulations with excellent recovery and without any interfering effect from excipients. Moreover, the presented approach was utilized to test the content uniformity of commercial tablets following the USP guidelines.
Collapse
Affiliation(s)
- Sayed M Derayea
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University Minia Egypt
| | - Mahmoud Abdelgaleel
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Deraya University New Mina City Minia Egypt
| | - Dalia M Nagi
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University Minia Egypt
| | - Mohamed Oraby
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Sohag University Sohag Egypt
| | - Pakinaz Y Khashaba
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Sphinx University New Assiut City Assiut Egypt
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Assiut University Assiut Egypt
| |
Collapse
|
3
|
Nagi DM, Abdelgaleel M, Derayea SM, Khashaba PY. Studying the kinetic of midodrine degradations using TLC Stability approach: Application to dosage form and human plasma. J Pharm Biomed Anal 2023; 229:115322. [PMID: 37001276 DOI: 10.1016/j.jpba.2023.115322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/21/2023] [Accepted: 02/28/2023] [Indexed: 03/07/2023]
Abstract
A simple, rapid and selective thin layer chromatographic method has been developed for estimation of the antihypotension drug, midodrine hydrochloride, in pure form, tablet, spiked plasma and artificially degraded samples. Separation was carried out using silica gel 60-F254 as a stationary and mobile phase consisting of methanol: methylene chloride: ammonia in ratio of 8:2:0.2. The detection was carried out at wavelength of 290 nm. The retardation factor was found to be 0.7 and 0.49 for midodrine and its main degradation product desglymidodrine. The method showed linearity for midodrine over a concentration range of 50-1500 ng/spot with good correlation and determination coefficient. The method was applied successfully for analysis of commercial tablets and oral drops with good recovery and without interference of excipients. The method also was applied for studying the stability of the cited drug under different stress conditions including acidic, alkaline, hydrolytic, oxidative and photo- degradations. Furthermore, the kinetic of acidic and alkaline degradations was investigated and the rate constants were found to be 0.620 and 0.074 K h-1 while half life time (t1/2) values were 1.12 and 9.32 h, respectively.
Collapse
Affiliation(s)
- Dalia M Nagi
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| | - Mahmoud Abdelgaleel
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt; Department of Pharmaceutical Analytical Chemistry, Deraya University, Faculty of Pharmacy, New Mina City, Minia, Egypt.
| | - Sayed M Derayea
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| | - Pakinaz Y Khashaba
- Department of Pharmaceutical Analytical Chemistry, Assiut University, Faculty of Pharmacy, Assiut, Egypt; Department of Pharmaceutical Chemistry, Sphinx university, Faculty of Pharmacy, New Assiut City, Assiut, Egypt
| |
Collapse
|
4
|
Khashaba PY, Abdelgaleel M, Derayea SM, Nagy DM. Development of a simple validated spectrofluorometric method for the assay of midodrine in tablets dosage form; Application to content uniformity testing. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 273:121046. [PMID: 35240554 DOI: 10.1016/j.saa.2022.121046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 06/14/2023]
Abstract
A new sensitive spectrofluorimetric technique has been established for the estimation of midodrine hydrochloride. This method depends on the condensation reaction of ortho-phthalaldehyde with the primary aliphatic amine of midodrine in the presence of 2-mercapto-ethanol. The pH of the medium was adjusted to 9.0 using 0.1 M borate buffer. The fluorescence of the product was measured at wavelength of 451 nm after excitation at 334 nm. The method was rectilinear over a concentrations range of 0.1 to 1.5 µg mL-1. The lower detection and quantitation limits were 31 and 94 ng mL-1, respectively. The method was investigated following the guidelines of the International Council of Harmonization. Analysis of commercial tablet dosage form was carried out successfully by the current method with excellent recovery percentages and with no influence from coexisted pharmaceutical additives .This method was used to evaluate the uniformity of the contents of commercial tablets according to the United States Pharmacopoeia.
Collapse
Affiliation(s)
- Pakinaz Y Khashaba
- Department of Pharmaceutical Analytical Chemistry, Assiut University, Faculty of Pharmacy, Assiut, Egypt; Department of Pharmaceutical Chemistry, Sphinx University, Faculty of Pharmacy, New Assiut City, Assiut, Egypt.
| | - Mahmoud Abdelgaleel
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt; Department of Pharmaceutical Analytical Chemistry, Deraya University, Faculty of Pharmacy, New Mina City, Minia, Egypt
| | - Sayed M Derayea
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| | - Dalia M Nagy
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| |
Collapse
|
5
|
Alharthi S, Batakoushy HA, Alharthy SA, Abd El-Magied MO, Salem WM. Electro-analytical sensing of anti-hypotensive agents: application to dosage forms and human urine. Toxicol Res (Camb) 2022; 11:245-254. [PMID: 35237429 PMCID: PMC8882789 DOI: 10.1093/toxres/tfac004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 01/10/2022] [Accepted: 01/13/2022] [Indexed: 11/12/2022] Open
Abstract
A new and valid method was developed for the quantitative voltammetric analysis of midodrine hydrochloride (MID) in pharmaceutical tablets (Midodrine) and biological samples. The method is based on electro-oxidation of MID supported by both disposable pencil electrode (PE) and glassy carbon electrode (GCE). The analysis was carried out using cyclic voltammetry, differential pulse voltammetry (DPV), and square wave voltammetry (SWV) techniques. The proposed analytical method was validated according to ICH guidelines. MID was successively assayed at concentration ranges of 1.15-6.55 and 0.58-3.05 μg mL-1 at PE. Also, MID was successively assayed at concentration ranges of 1.15-5.28 and 2.86-27.6 μg mL-1 at GCE for DPV and SWV methods, respectively. The proposed method was successfully used for the analysis of MID in its dosage form and human urine with good recoveries of 99.66 ± 0.33, 99.8 ± 0.45 at PE and 99.8 ± 0.25, 98.7 ± 1.27 at GCE for the DPV and SWV methods, respectively. The suggested method could be applied to the studied drug in the quality control lab as well as in its pharmacokinetic studies.
Collapse
Affiliation(s)
- Sarah Alharthi
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Hany A Batakoushy
- Pharmaceutical Analysis Department, Faculty of Pharmacy, Menoufia University, Shebin El-Kom, Menoufia 32511, Egypt
| | - Saif A Alharthy
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Mahmoud O Abd El-Magied
- Research Sector, Nuclear Materials Authority, P.O. Box 530, El Maadi, Cairo 11936, Egypt,Corresponding author: (MOA)
| | - Waheed M Salem
- Medical Laboratories Department, Faculty of Applied Health Sciences Technology, Menoufia University, Shebin El-Kom, Menoufia 32511, Egypt
| |
Collapse
|
6
|
Omar MA, Nagy DM, Halim ME. Simple ultrasensitive spectrofluorimetric method for determination of midodrine in its tablet form: Application to content uniformity testing. LUMINESCENCE 2019; 34:854-858. [PMID: 31338979 DOI: 10.1002/bio.3682] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 05/23/2019] [Accepted: 06/12/2019] [Indexed: 11/07/2022]
Abstract
A novel, simple, sensitive method was developed for determining midodrine spectrofluorimetrically in both its raw pure form and its tablet form. This study is based on the native fluorescence of midodrine and discusses the optimum solvent used and the wavelength range. The presented method was then validated with respect to linearity, accuracy, precision, and limits of detection and quantitation. The constructed calibration curve showed a linear range of 0.1-2.0 μg/ml. The limit of detection and limit of quantitation values were 0.03 and 0.10 μg/ml respectively. Finally, content uniformity testing was applied according to the United States Pharmacopoeia by adapting the presented method.
Collapse
Affiliation(s)
- Mahmoud A Omar
- Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Medinah, Saudi Arabia
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| | - Dalia M Nagy
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| | - Monica E Halim
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| |
Collapse
|
7
|
Omar MA, Nagy DM, Halim ME. Design and strategy approach for spectrofluorimetric determination of midodrine in tablets: Application to content uniformity testing. Microchem J 2019. [DOI: 10.1016/j.microc.2019.01.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
8
|
Omar MA, Nagy DM, Halim ME. The convenient use of fluorescamine for spectrofluorimetric determination of midodrine hydrochloride in pure form and its tablets formulation: Application to content uniformity testing. LUMINESCENCE 2018; 34:84-89. [PMID: 30536965 DOI: 10.1002/bio.3582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/23/2018] [Accepted: 11/07/2018] [Indexed: 11/06/2022]
Abstract
A novel sensitive and simple spectrofluorimetric method was developed then validated for determination of midodrine in both its authentic pure form and its tablets. This method is based on the reaction between midodrine's aliphatic primary amine moiety with fluorescamine reagent, using borate buffer at pH 7.8 and yielding a highly fluorescent product whose fluorescence intensity was measured at 462 nm after excitation at 388 nm. This method represents the first attempt for determination of midodrine spectrofluorimetrically. A calibration curve was constructed showing that the linear range was 0.2-3.0 μg/ml. The limit of detection and limit of quantitation values were 0.06 and 0.19 μg/ml respectively. The correlation coefficient (r) and the determination coefficient (r2 ) values were 0.9992 and 0.9984 respectively. The proposed method was validated according to ICH guidelines and successfully applied for determination of midodrine in its tablets with an overall % recovery of 99.56 ± 0.95. Finally, the presented method was adapted to study the content uniformity test according to United States Pharmacopeia guidelines.
Collapse
Affiliation(s)
- Mahmoud A Omar
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| | - Dalia M Nagy
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| | - Monica E Halim
- Analytical Chemistry Department, Faculty of Pharmacy, Minia University, Minia, Egypt
| |
Collapse
|
9
|
Patel DP, Nair S, Suhagia BN, Patel BM. A novel, sensitive and selective method of UPLC/MS-MS for rapid simultaneous determination of midodrine and its active metabolite desglymidodrine in human plasma: Application to support bioequivalence study in healthy human volunteers. J Pharm Biomed Anal 2016; 131:355-363. [PMID: 27639073 DOI: 10.1016/j.jpba.2016.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 11/19/2022]
Abstract
A specific, rapid, sensitive and selective ultra-performance liquid chromatography - tandem mass spectrometry has been developed for the simultaneous determination of midodrine and desglymidodrine in human plasma. The analytes and its deuterated analogs were quantitatively extracted from 100μL of human plasma by solid phase extraction technique. Separation of analytes was achieved on the Waters Acquity UPLC BEH C18 (50×2.1mm, 1.7μm) column using acetonitrile-4.0mM ammonium formate, pH 2.5(90:10, v/v) as mobile phase. The protonated analytes were quantified by selected reaction monitoring in the positive ionization mode by triple quadrupole mass spectrometer. The calibration plots were linear over the concentration range of 0.050-50.0ng/mL. The intra-batch and inter-batch precision (%CV) across quality control levels was <4.0 and the% mean relative recovery was ≥96%. Various other parameters like stability in different conditions; matrix effect and reproducibility of the method were performed in accordance with the guidelines specified by the USFDA for bioanalytical method development and validation. The developed method was successfully administered to the pharmacokinetics study of 5 mg midodrine tablet in 12 healthy subjects. Reproducibility of assay was proved by reanalysis of 48 incurred samples.
Collapse
Affiliation(s)
- Daxesh P Patel
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, United States
| | - Sneha Nair
- Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad 380009, India
| | | | - Bhargav M Patel
- Department of Chemistry, St. Xavier's College, Navrangpura, Ahmedabad 380009, India.
| |
Collapse
|
10
|
Ali AA, Al-Ghobashy MA, Farid SF, Kassem MA. Development and validation of LC–MS/MS assay for the determination of the prodrug Midodrine and its active metabolite Desglymidodrine in plasma of ascitic patients: Application to individualized therapy and comparative pharmacokinetics. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 991:34-40. [DOI: 10.1016/j.jchromb.2015.03.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/25/2015] [Accepted: 03/31/2015] [Indexed: 02/03/2023]
|
11
|
Barth T, Aleu J, Pupo MT, Bonato PS, Collado IG. HPLC Analysis of Midodrine and Desglymidodrine in Culture Medium: Evaluation of Static and Shaken Conditions on the Biotransformation by Fungi. J Chromatogr Sci 2012; 51:460-7. [DOI: 10.1093/chromsci/bms163] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
12
|
Raj SR, Faris PD, McRae M, Sheldon RS. Rationale for the prevention of syncope trial IV: assessment of midodrine. Clin Auton Res 2012; 22:275-80. [PMID: 22610268 DOI: 10.1007/s10286-012-0167-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 04/25/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND Vasovagal syncope is a common problem associated with a poor quality of life, which improves when the frequency of syncope is reduced. Effective pharmacological therapies for vasovagal syncope have been elusive. Midodrine is a pro-drug whose primary metabolite is an alpha-1 adrenoreceptor agonist. A few studies have suggested that it may be beneficial in syncope, but all have had significant methodological limitations. A placebo-controlled clinical trial of midodrine for the prevention of vasovagal syncope is needed. STRUCTURE OF STUDY The prevention of syncope trial IV (POST 4) is a multicenter, international, randomized, placebo-controlled study of midodrine in the prevention of vasovagal syncope. The primary end point is the time to first recurrence of syncope. Patients will be randomized 1:1 to receive midodrine 10-30 mg/day or matching placebo, and followed for 1 year. Secondary end points include syncope frequency, presyncope, and quality of life. Primary analysis will be performed with an intention-to-treat approach, with a secondary on-treatment analysis. POWER CALCULATIONS A total sample size of 112, split equally between the two groups, achieves 85 % power to detect a 50 % relative risk reduction when the event rates are 55 and 27.5 % in the placebo and midodrine arms. Allowing for 20 % dropout, we propose to enroll 140 patients. REGISTRATION POST 4 is registered with http://www.clinicaltrials.gov (NCT01456481). IMPLICATIONS This study will be the first adequately powered trial to determine whether midodrine is effective in preventing vasovagal syncope. If it is effective, then midodrine may become the first-line pharmacological therapy for this condition.
Collapse
Affiliation(s)
- Satish R Raj
- Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University, Nashville, TN 37232-2195, USA.
| | | | | | | |
Collapse
|
13
|
Akimoto M, Iida I, Itoga H, Miyata A, Kawahara S, Kohno Y. Thein vitro metabolism of desglymidodrine, an active metabolite of prodrug midodrine by human liver microsomes. Eur J Drug Metab Pharmacokinet 2004; 29:179-86. [PMID: 15537169 DOI: 10.1007/bf03190595] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The human cytochrome P450 (CYP) isoforms catalyzing the oxidation metabolism of desglymidodrine (DMAE), an active metabolite of midodrine, were studied. Recombinant human CYP2D6, 1A2 and 2C19 exhibited appreciable catalytic activity with respect to the 5'-O-demethylation of DMAE. The O-demethylase activity by the recombinant CYP2D6 was much higher than that of other CYP isoforms. Quinidine (a selective inhibitor of CYP2D6) inhibited the O-demethylation of DMAE in pooled human microsomes by 86%, while selective inhibitors for other forms of CYP did not show any appreciable effect. Although the activity of CYP2D6 was almost negligible in the PM microsomes, the O-demethylase activity of DMAE was found to be maintained by about 25% of the pooled microsomes. Furafylline (a selective inhibitor of CYP1A2) inhibited the M-2 formation in the PM microsomes by 57%. The treatment of pooled microsomes with an antibody against CYP2D6 inhibited the formation of M-2 by about 75%, whereas that of the PM microsomes did not show drastic inhibition. In contrast, the antibody against CYP1A2 suppressed the activity by 40 to 50% in the PM microsomes. These findings suggest that CYP2D6 have the highest catalytic activity of DMAE 5'-O-demethylation in human liver microsomes, followed by CYP1A2 to a small extent.
Collapse
Affiliation(s)
- Masayuki Akimoto
- Research Center, Taisho Pharmaceutical Co, Ltd, Kita-ku, Saitama-shi, Saitama, Japan
| | | | | | | | | | | |
Collapse
|
14
|
Yoshida H, Ohno Y, Yoshikuni K, Todoroki K, Nohta H, Yamaguchi M. Determination of midodrine in human plasma by high-performance liquid chromatography with fluorescence detection. ANAL SCI 2003; 19:317-9. [PMID: 12608767 DOI: 10.2116/analsci.19.317] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A simple and sensitive fluorometric high-performance liquid chromatographic method was developed for the determination of midodrine in human plasma. After liquid-liquid extraction from plasma, the drug and 2-phenylglycinol (internal standard) were convened into the corresponding fluorescent derivatives by reaction with 3,4-dihydro-6,7-dimethoxy-4-methyl-3-oxoquinoxaline-2-carbonyl chloride, a fluorescence derivatization reagent for amines. The derivatives were separated within 30 min on a reversed-phase column using isocratic elution with acetonitrile-methanol-water (10:30:60, v/v) and were detected spectrofluorometrically at 485 nm with excitation at 400 nm. The detection limit for midodrine was 0.3 pmol (76 pg) per mL plasma at a signal-to-noise ratio of 3.
Collapse
Affiliation(s)
- Hideyuki Yoshida
- Faculty of Pharmaceutical Sciences, Fukuoka University, Nanakuma, Johnan, Fukuoka 814-0180, Japan
| | | | | | | | | | | |
Collapse
|
15
|
Stalcup AM, Faulkner JR, Tang Y, Armstrong DW, Levy LW, Regalado E. Determination of the enantiomeric purity of scopolamine isolated from plant extract using achiral/chiral coupled column chromatography. Biomed Chromatogr 1991; 5:3-7. [PMID: 2032020 DOI: 10.1002/bmc.1130050103] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The optical purity of scopolamine derived from Datura sanguinea was determined using coupled column chromatography. A C18 column was used to separate scopolamine from the additional alkaloids and other biological material present in the vegetal extract. The C18 column was coupled through a six-port switching valve to two beta-cyclodextrin columns in series which were used to resolve the scopolamine enantiomers. A single acetylated beta-cyclodextrin column gives equivalent results to the native cyclodextrin columns because of slightly higher enantioselectivity for scopolamine. A multistep extraction procedure is used to isolate scopolamine from the vegetal material. 4-6% of the scopolamine in the final extract was found to be the d enantiomer. Sample extracts as well as commercial scopolamine hydrobromide were treated under various conditions commonly encountered during typical commercial extraction procedures and analyzed in order to determine if the d enantiomer was present in the original material or if it was produced during the extraction process and, if so, determine which step and conditions contribute to racemization. Both the salt and the extract were found to be susceptible to racemization under basic conditions (greater than or equal to pH 9) although the extract appeared to be more susceptible than the salt. Tropic acid formed from the hydrolysis of scopolamine seemed to be completely racemized even though the remaining scopolamine was only partially racemized. Within experimental error, no d enantiomer was found in the original fresh plant material.
Collapse
Affiliation(s)
- A M Stalcup
- Department of Chemistry, University of Missouri-Rolla 65401
| | | | | | | | | | | |
Collapse
|