Application of DSC, IST, and FTIR study in the compatibility testing of nateglinide with different pharmaceutical excipients

Experiments were done to assess the compatibility of nateglinide (NTG) with selected excipients in the development of immediate release tablets of NTG by thermal and isothermal stress testing (IST) techniques. To evaluate the drug excipient compatibility, different techniques such as differential scanning calorimetric (DSC) study, infrared (IR) spectrophotometric study, and IST were adopted. The results of DSC study showed that magnesium stearate exhibited some interaction with NTG. However, the results of IR and IST studies showed that all the excipients used in the formula were compatible with NTG. The optimized formulation developed using the compatible excipients were found to be stable after 3 months of accelerated stability studies (40 +/- 2 degrees C and 75 +/- 5% RH). Overall, compatibility of excipients with NTG was successfully evaluated using the combination of thermal and IST methods and the formulations developed using the compatible excipients was found to be stable.