Determination of Chemical Stability of Two Oral Antidiabetics, Metformin and Repaglinide in the Solid State and Solutions Using LC-UV, LC-MS, and FT-IR Methods.

Firstly, metformin and repaglinide were degraded under high temperature/humidity, UV/VIS light, in different pH and oxidative conditions. Secondly, a new validated LC-UV method was examined, as to whether it validly determined these drugs in the presence of their degradation products and whether it is suitable for estimating degradation kinetics. Finally, the respective LC-MS method was used to identify the degradation products.