Comparison of bioavailability and pharmacokinetics of diclofenac sodium and diclofenac potassium in normal and alloxan-diabetic rabbits

The present study was undertaken to compare the bioavailability and pharmacokinetic parameters of diclofenac sodium and diclofenac potassium in normal and experimentally induced diabetic state in 24 rabbits using a validated reversed phase HPLC method with a washout period of one week. Biochemical and physiological parameters were measured in normal and diabetic rabbits. Primary kinetic parameters i.e. AUC_0-∞, C_max, t_max and other disposition kinetics were determined with non-compartmental procedure. A paired t-test for normal and alloxan treated rabbits revealed a significant decrease in packed cell volume and a significant increase in glucose, total lipids, total proteins, albumin and globulin were observed in diabetic (metabolically altered) rabbits. Plasma concentration of diclofenac (sodium) and diclofenac (potassium) decreased in diabetic condition. Significantly high concentration of diclofenac (potassium) was observed in normal and diabetic conditions as compared to diclofenac (sodium). The variation in bioavailability and disposition of diclofenac sodium and diclofenac potassium in diabetic state will require adjustment of the dosage regimen prescribed for diabetics in clinical setting.