A comparative study of release profiles of Coccinia cordifolia and Catharanthus roseus with standard antidiabetic agent using rat intestine

Abstract

Matured leaves of Coccinia cordifolia and Catharanthus roseus were collected, dried and extracted with 95% ethanol. Solvents were evaporated and suspensions at a concentration of 40 mg/ml were prepared from the residues using phosphate buffer. The aim of the study is to elucidate the release pattern of these extracts in acidic and basic environment. 1 ml suspension of each plant was poured into the intestine fragment prepared from sacrificed rats. The filled pieces of intestine were bound vertically to the paddle of modified dissolution apparatus and rotated at 50 rpm in phosphate buffer incubation medium at pH 3 and pH 7.4. Metformin hydrochloride was used as the standard. Percent releases of Coccinia cordifolia, Catharanthus roseus and metformin hydrochloride were determined by analyzing the UV absorbance data at different time interval and the result obtained at pH 3 was compared with that of pH 7.4. Experimental result with these extracts and drug showed burst release initially followed by gradual release at pH 3.0 and the value of R2 (correlation coefficient of percent release versus time) indicates that the release pattern was better maintained at pH 3.0 for coccinia and catharanths while that was better maintained at pH 7.4 for metformin hydrochloride.