Background: The use of generic versions of drugs, such as those for glimepiride [Amaryl, Amarel, Solosa (sanofi-aventis, Paris, France)], a third-generation sulfonylurea, can reduce healthcare costs. However, the quality and performance of these generics should be carefully evaluated.
Methods: We compared the quality and behavior of 23 marketed generic forms with Amaryl (all 2 mg) under stressed conditions. Deblistered samples were stored at 60 degrees C for 21 days in order to mimic temperature-stressed conditions. Samples were analyzed at Days 0, 7, and 21 for content of active compound, levels of impurities, levels of residual solvent (Day 0 only), and dissolution profile, and results were compared against Amaryl specifications.
Results: Levels of the degradation product GS [corrected] were < or = 1% in all products at Day 0; however, GS levels [corrected] increased to above Amaryl specifications [corrected] in two generics at Day 7 (Dolcyl and GLA-DM) [corrected] and in four generics at Day 21 [Dolcyl, GLA-DM, glimepiride (Hanni), and glimepirida (Esterlina)] (Fig. 2) [corrected] Total levels of other impurities and levels of residual solvents were above Amaryl specifications (<or=1.0% and >1,400 ppm, respectively) in two generics at Day 0. At Day 0, the dissolution of 12 generics (52%) failed to meet Amaryl specifications (>or=85% dissolved in 15 min); this trend was confirmed at Day 21. Overall, 74% (17 of 23) of the generics were not of equivalent quality or performance compared with Amaryl.
Conclusions: This study indicates that a relevant percentage of glimepiride generics may offer reduced quality and performance when compared with the original drug.