Stability study of enalapril maleate in tablet form using high performance liquid chromatography techniques

Abstract

This paper demonstrates the stability studies of Enalapril Maleate. The results observed from the stability during the storage of Enalapril Maleate tablets give better result with alkali compounds e.g. sodium bicarbonate. The influence of various parameters such as heat, moisture was investigated. The degradation of Enalapril Maleate has been followed by using an HPLC. Enalapril Maleate is much stable when it is prepared in form of Enalapril sodium salt. Enalapril Maleate alone showed high stability for temperature under dry and humid conditions, however it became unstable when mixed with the drug-matrix in its tablet formulations and exposed to the same conditions. The pathway of degradation of Enalapril Maleate was found to be pH dependent. The Enalapril Maleate show better stability in pH range 2.00-7.00. Enalapril Maleate shows the incompatibilities with various excipients silicon dioxide, lactose, microcrystalline cellulose & magnesium stearate.