ABSTRACT
Objective:To evaluate the systemic absorption and safety of multiple doses of topical tazarotene/betamethasone dipropionate cream in healthy subjects and patients with psoriasis.Methods:From September 2008 to April 2009, 12 healthy subjects collected from Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College were randomly and equally divided into tazarotene 0.15%/betamethasone dipropionate 0.15% cream group and tazarotene 0.2%/betamethasone dipropionate 0.2% cream group; these subjects were instructed to apply 0.03 g of the test drug per day on each of the 4 body sites, including the flexor aspects of bilateral forearms, waist and back, for 7 consecutive days, and venous blood samples were obtained before, and 1, 3, 5 and 7 days after the start of drug application. From October 2010 to August 2011, 60 patients with non-cephalic psoriasis collected from the Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College were randomly divided into 3 groups at a ratio of 3∶1∶1, i.e., tazarotene 0.05%/betamethasone dipropionate 0.05% cream group ( n = 36) and tazarotene 0.05% gel group ( n = 12) topically treated with a cream vehicle in the morning and the test drug at night, and betamethasone dipropionate 0.05% cream group ( n = 12) topically treated with the test drug twice a day (once in the morning and again in the evening) ; the treatment lasted 6 consecutive weeks, and venous blood samples were collected before, and 2, 4 and 6 weeks after drug application. Liquid chromatography-tandem mass spectrometry was performed to determine the concentrations of tazarotenic acid and betamethasone in plasma. During the trial, adverse events in the subjects were recorded, routine blood and urine examinations were carried out, and liver and kidney function were evaluated before and after treatment. Results:The plasma concentrations of tazarotenic acid and betamethasone in the 12 healthy subjects were below the lower limit of quantitation (0.04 μg/L) after 1-, 3-, 5- and 7-day treatment. After the consecutive treatment, tazarotenic acid and betamethasone were detected in 2 (5.56%) and 4 (11.11%) patients respectively at week 2, 4 or 6 in the tazarotene 0.05%/betamethasone dipropionate 0.05% cream group, and the highest plasma concentrations of tazarotenic acid and betamethasone were 0.112 and 0.201 μg/L respectively; in the betamethasone dipropionate 0.05% cream group, betamethasone was detected in 2 of 12 patients, and the highest plasma concentration of betamethasone was 0.112 μg/L. No test drug-related systemic adverse reactions or laboratory abnormalities were observed in any of the healthy subjects or patients.Conclusion:Multiple doses of topical tazarotene/betamethasone dipropionate cream has advantages of little systemic absorption, no long-term accumulation and good systemic safety.
ABSTRACT
A simple and rapid method was developed based on high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to determine sivelestat and its metabolite XW-IMP-A in human plasma. After a simple protein precipitation, the samples and internal standards were analyzed on a C18 column by a gradient elution program. The mobile phase consisted of 30% acetonitrile in methanol and 5 mmol · L(-1) ammonium acetate at a flow rate of 0.7 mL · min(-1). The mass spectrometric data was collected in multiple reaction monitoring mode (MRM) in the negative electrospray ionization. The standard curves were linear in the range of 10.0-15,000 ng · mL(-1) for sivelestat, and 2.50-1000 ng · mL(-1) for XW-IMP-A. The low limits of quantitation were identified at 10.0 and 2.50 ng · mL for sivelestat and XW-IMP-A, respectively. The intra- and inter-day precision were within 11.3% and 13.1% for sivelestat and XW-IMP-A, and accuracy was 0.3% and 0.6% for sivelestat and XW-IMP-A, within the acceptable limits across all concentrations. The method was successfully validated in the pharmacokinetic study of sivelestat in healthy Chinese volunteers.
ABSTRACT
A rapid, sensitive and convenient LC-MS/MS method was developed for the determination of γ-aminobutyric acid (GABA) in human plasma. d2-γ-Aminobutyric acid (d2-GABA) was synthesized as internal standard (IS). After extraction from human plasma by protein precipitation with acetonitrile, all analytes were separated on a Luna HILIC column (100 mm x 3.0 mm, 3 μm) using an isocratic mobile phase of water: acetonitrile: formic acid (20 : 80 : 0.12) with a flow rate of 0.5 mL x min(-1). Acquisition of mass spectrometric data was performed in multiple reaction monitoring mode (MRM) in positive electrospray ionization using the transitions of m/z 104 --> 69 for GABA and m/z 106 --> 71 for d2-GABA. The method was linear in the concentration range of 5.00 to 1 000 ng x mL(-1). The intra- and inter-day precisions were within 9.9%, and accuracy ranged from 99.1% to 104%, within the acceptable limit across all concentrations. The method was successfully applied to a pharmacokinetic study of GABA tablets in healthy Chinese volunteers.
ABSTRACT
A simple, sensitive, selective, and reproducible liquid chromatography-tandem mass spectrometric method was developed for the simultaneous determination of repaglinide and metformin in human plasma using d5-repaglinide and d6-metformin as internal standards (ISs). After a simple protein precipitation using acetonitrile as the precipitation solvent, both analytes and ISs were separated on a Venusil ASB C 18 (150 mm x 4.6 mm, 5 microm) via gradient elution using acetonitrile--10 mmol x L(-1) ammonium acetate as the mobile phase. A chromatographic total run time of 7.5 min was achieved. Mass spectrometric detection was conducted with atmospheric pressure chemical ionization under positive-ion and multiple-reaction monitoring modes. The method was linear over the 0.2 to 60.0 ng x mL(-1) concentration range for repaglinide and over the 4 to 1 000 ng x mL(-1) range for metformin. For both analytes, the intra- and inter-accuracies and precisions were within the +/- 15% acceptable limit across all concentrations. The validated method was successfully applied to a clinical bioequivalence study.