Original Article
Mamdouh R.Rezk, Sherif A.Abdel
Abstract
Two methods namely, coupled TLC densitometry and high performance liquid chromatography, were used to determine sitagliptin and simvastatin simultaneously in their pharmaceutical dosage form. A TLC separation with densitometric detection of both drugs was achieved using benzene: n-butanol: triethylamine (9:2:0.5, by volumes] as a developing solvent. Furthermore, a high performance liquid chromatographic procedure with ultraviolet detection at 220 nmwas developed for the separation and determination of the studied drugs using a C18 column. The mobile phase was composed of water: methanol: acetonitrile (1: 2: 2, by volumes). The final pH was adjusted to 4.6 ± 0.1 with O-phosphoric acid. The proposed methods were successfully applied for the determination of the studied drugs in pure forms, their mixtures and in pharmaceutical formulation containing them.