Influence of Tamarind Pulp on pharmacodynamics and pharmacokinetics of Gliclazide in Rats/Rabbits

Abstract

The study was hypothesized to evaluate the safety of gliclazide therapy in the presence of Tamarind pulp (TP) in rats and rabbits. Studies in rats and rabbits were conducted with oral doses of gliclazide, Tamarind and their combination. Blood samples were analyzed for blood glucose by GOD/POD method and serum gliclazide levels by HPLC method. TP alone reduced blood glucose levels in rats/rabbits and has slightly altered the hypoglycaemic effect of gliclazide when administered together. The serum gliclazide levels were reduced significantly and pharmacokinetic parameters of gliclazide were altered significantly in presence of TP, but did not result in the significant change in blood glucose levels, indicating the reduction in the absorption of TP itself along with absorption of gliclazide. The decrease in the pharmacokinetic parameters like AUC, Cmax, Ka, Cl and increase in the T1/2 indicate the decrease in the absorption and elimination of gliclazide, which might be due to laxative property of TP. The increase in Vd might be due to presence of salt in the TP as preservative. The decrease in the elimination of gliclazide might be due to decreased serum levels, resulted from decreased absorption and increased distribution. The decrease in the serum levels of gliclazide did not result in decreased activity of gliclazide, since TP itself found to produce hypoglycaemia. In conclusion, the combination might be safe with respect to its hypoglycaemic effect, but care should be taken when gliclazide is administered with multiple doses of TP in a clinical situation.