Arzneimittelforschung 2012; 62(01): 22-26
DOI: 10.1055/s-0031-1295428
Original Article
© Georg Thieme Verlag KG Stuttgart · New York

Bioequivalence and Pharmacokinetic Comparison of 3 Metformin Extended/Sustained Release Tablets in Healthy Indian Male Volunteers

L. S. Batolar
1   Faculty of Pharmaceutical Medicine, Jamia Hamdard, New Delhi, India
M. Iqbal
3   College of Pharmacy, King Saud University, Riyadh, KSA
T. Monif
2   Clinical Pharmacology and Pharmacokinetics, Ranbaxy Research Laboratory, Gurgaon, India
A. Khuroo
2   Clinical Pharmacology and Pharmacokinetics, Ranbaxy Research Laboratory, Gurgaon, India
P. L. Sharma
1   Faculty of Pharmaceutical Medicine, Jamia Hamdard, New Delhi, India
› Author Affiliations
Further Information

Publication History

received 08 October 2011

accepted 02 November 2011

Publication Date:
10 January 2012 (online)


This study was undertaken to compare the bioavailability and pharmacokinetic properties of 3 marketed product of metformin (CAS 1115-70-4) extended/sustained release formulation in Indian male volunteers. Study was designed as an open-label, randomized, 3-treatment, single-dose, crossover, bioavailability study comparing 3 marketed brands of 500 mg metformin extended/sustained release tablets in 18 healthy human male volunteers under fed condition. A single oral dose of 500 mg metformin sustained release products, test A (Glycomet SR), test B (Bigomet SR) and extended release reference product was administered as per computer generated randomization schedule during 3 period of the study having 7 days of washout period. A liquid Chromatography mass spectroscopy method for the determination of metformin in human plasma was developed and validated using metformin-D6 as an internal standard. A noncompartment pharmacokinetic method was employed to determine the pharmacokinetic parameters (Cmax, Tmax, AUC0–t, AUC0–∞ and t½) of metformin using WinNonlin-Node 4.0 software. Cmax, AUC0–t and AUC0–∞ were used to test for bioequivalence after log transformation of plasma data. The predetermined regulatory range of 90% CI for bioequivalence was 0.80 to 1.25. The 90% confidence intervals for log transformed data for Cmax, AUC0–t and AUC0–∞ for test A vs. reference were 82.11–98.91, 86.29–102.17 and 86.34–102.59 respectively whereas for test B vs. reference were 104.39–125.76, 94.78–112.22 and 92.85–110.33 respectively. The results of this study suggest that the test A was bioequivalent to reference product, whereas test B was not as per regulatory defined criteria.

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