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ABSTRACT: Abstract
Aim: To compare the bioavailability of two Azithromycin tablet formulations 500 mg Azivol® tablets as test
formulation and 500 mg Zithromax® tablets as reference formulation.
Methods: A single-dosed, open-label randomized two-way crossover design under fasting period with two
weeks wash-out period was evaluated in 24 subjects. For the analysis of pharmacokinetic properties, the blood
samples were drawn taken up to 120 hours after dosing. Plasma concentration of Azithromycin was determined
using liquid chromatography – tandem mass spectrometry method with TurboIon Spray mode. Pharmacokinetic
parameters AUC0-t, AUC0-∞ and Cmax were tested for bioequivalence after log-transformation of data and ratios of tmax
were evaluated non-parametrically.
Results: The point estimates and 90% confidence intervals (CI) for AUC0-t, AUC0-∞, and Cmax for Azithromycin
were 94.63% (86.27-103.81%), 95.35% (87.15-104.31%), 94.16% (80.31-110.41%) respectively.
Conclusion: These results indicated that the two formulations of Azithromycin were bioequivalent and thus may
be prescribed interchangeably.
Journal of Bioequivalence & Bioavailability 05/2012; 4(5):048-051.
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ABSTRACT: The bioavailability of two 0.4 mg tamsulosin sustained-release film-coated tablet formulations was compared; using generic tablets (Prostam(®)) as test formulation and the originator product as reference formulation. Twenty-four subjects were included in this single-dose, open-label, randomized two-way crossover design following an overnight fasting. A one-week wash-out period was applied. Blood samples were drawn up to 72 h following drug administration. Plasma concentration of tamsulosin was determined by liquid chromatography-tandem mass spectrometry method with TurboIonSpray mode. Pharmacokinetic parameters AUC(0-t,) AUC(0-∞), C (max) and t (½) were determined and used for bioequivalence evaluation after log-transformation, whereas t (max) ratios were evaluated non-parametrically. The estimated point and 90% confidence intervals (CI) for AUC(0-t,) AUC(0-∞), C (max) and t (½) were 109.55% (96.41-124.49%), 109.94% (96.85-124.81%), 105.87% (92.88-120.67%) and 100.00% (90.56-110.43%), respectively. These results indicated that the two formulations of tamsulosin were bioequivalent; therefore they may be prescribed interchangeably.
European Journal of Drug Metabolism and Pharmacokinetics 03/2011; 36(2):109-13. · 0.36 Impact Factor
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ABSTRACT: The bioavailability of two 300 mg irbesartan (CAS 138402-11-6)/12.5 mg hydrochlorothiazide (CAS 58-93-5) tablet formulations was compared, using Co-Ir-vell tablets as test formulation and the originator product as reference formulation.
Twenty-four subjects were included in this single-dose, open-label, randomized two-way crossover study following an overnight fasting. A two-week wash-out period was applied. Blood samples were drawn up to 48 h following drug administrations. Irbesartan and hydrochlorothiazide plasma concentrations were determined by liquid chromatography-tandem mass spectrometry method with TurboIonSpray mode. Pharmacokinetic parameters AUC(0-t), AUC(0-infinity), Cmax and t were determined and used for bioequivalence evaluation after log-transformation, whereas t max ratios were evaluated non-parametrically.
The estimated point and 90% confidence intervals (CI) for AUC(0-t), AUC(0-infinity), Cmax and t for irbesartan were 97.74% (85.40-111.86%), 96.36% (83.25-111.55%), 103.30% (90.65-117.71%), 92.38% (82.68-103.21%) and for hydrochlorothiazide, 106.30% (97.72-115.63%), 106.28% (98.14-115.10%), 108.01% (95.48-122.18%), 105.52% (96.70-115.14%), respectively.
These results indicated that the two formulations of irbesartan/hydrochlorothiazide were bioequivalent; therefore they may be prescribed interchangeably.
Arzneimittel-Forschung 01/2010; 60(12):749-53. · 0.72 Impact Factor
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ABSTRACT: A simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method employing electronspray ionization was developed and validated for quantification of losartan and its carboxylic acid metabolite in human plasma using irbesartan as internal standard (IS). Following a simple pretreatment procedure, the analytes were separated using a gradient mobile phase on reverse phase C18 column. Selected reaction monitoring was specific for losartan, losartan acid and irbesartan. The method validation demonstrated the specificity, lower limit of quantification, accuracy and precision of measurements. The assay exhibited a linear dynamic range of 2.0-400 ng/mL for losartan and 1.85-370 ng/mL for losartan acid. A run time of 3.5 min for each sample made it possible to analyze more than 200 samples per day. The validated method has been successfully used to analyze human plasma samples for application in bioavailability/bioequivalence studies.
Journal of pharmaceutical and biomedical analysis 02/2009; 49(3):862-7. · 2.45 Impact Factor
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ABSTRACT: To compare the bioavailability of two dexamethasone (CAS 50-02-2) tablet formulations -- 4 mg Dexmethsone tablets as test formulation and 4 mg tablets of the originator product as reference formulation.
The study was conducted according to an open-label, randomized two-way crossover design with a one-week washout period. Twenty-four volunteers received a single dose of two tablets of the two different dexamethasone formulations. Blood samples for pharmacokinetic profiling were taken up to 24 h after drug administration in fasting condition. Plasma concentrations of dexamethasone were determined with a validated HPLC method using an ultraviolet detector. Pharmacokinetic parameters were calculated from observed plasma concentration-time profiles.
The mean AUC0-t, AUC0-infinity, and Cmax were 501.61 ng x h/ml, 518.88 ng x h/ ml and 98.02 ng/ml, respectively for the test formulation and 507.10 ng x h/ml, 525.20 ng x h/ml and 97.82 ng/ml, respectively, for the reference formulation. The median Tmax, for both formulations was 0.75 h. Plasma elimination half-lives (t1/2) were 3.44 h (test) and 3.38 h (reference). The point estimates and 90% confidence intervals (CI) for AUC0-t, AUC0-infinity and Cmax were 98.92% (94.62-103.41%), 98.80% (94.51-103.28%) and 100.20% (91.43-109.81%), respectively, satisfying the bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration guidelines.
These results indicate that the two formulations of dexamethasone are bioequivalent and thus may be prescribed interchangeably.
Arzneimittel-Forschung 02/2009; 59(4):191-4. · 0.72 Impact Factor
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ABSTRACT: To compare the bioavailability of two estazolam (CAS 29975-16-4) tablet formulations (Estalin 2 mg tablets as test formulation and 2 mg tablets of the originator product as reference formulation).
The study was conducted according to an open label, randomized two-way cross-over design with a two-week washout period. Twenty-four subjects received each of the two estazolam formulations. Blood samples for pharmacokinetic profiling were taken up to 72 h after drug administration in fasting condition. Plasma concentrations of estazolam were determined with a validated HPLC method with ultraviolet detection. Pharmacokinetic parameters were calculated from observed plasma concentration-time profiles.
The mean AUC(0-t), AUC(0-infinity) and Cmax were 2581.38 ng x h/mL, 2934.37 ng x h/mL and 95.25 ng/mL, respectively for the test formulation and 2835.75 ng x h/ mL, 3207.73 ng x h/mL and 99.32 ng/mL, respectively, for the reference formulation. The median Tmax for both formulations was 1 h. The point estimates and 90% confidence Intervals for AUC(0-t), AUC(0-infinity) and Cmax were 91.03% (87.48-94.72%), 91.48% (86.67-96.55%) and 95.90% (92.60-99.31%) respectively, satisfying the bloequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration guidelines.
These results indicate that two formulations of estazolam are bioequivalent and, thus, may be prescribed interchangeably.
Arzneimittel-Forschung 02/2008; 58(10):501-4. · 0.72 Impact Factor
