Ketoprofen suppository dosage forms: in vitro release and in vivo absorption studies in rabbits

In vitro release of ketoprofen from suppository bases and in vivo absorption in rabbits were studied. Suppositories containing 50 mg of ketoprofen were prepared using theobroma oil, esterified (c10-c18) fatty acids, and polyethylene glycol 1000 bases. The displacement values of the drug were determined and found to be of the order of theobroma oil > esterified (c10-c18) fatty acids and polyethylene glycol 1000 bases. The suppository hardness data revealed that the theobroma oil base produced relatively brittle suppositories. Using the USP dissolution method, the release of ketoprofen was observed to be greatest from polyethylene glycol 1000 suppositories. With the dialysis technique, the maximum release of drug was obtained from theobroma oil suppository containing polysorbate 40 at a 6% level. Selected suppository formulations were evaluated for rectal absorption studies in rabbits. The in vivo data showed that the optimum drug absorption took place from the polyethylene glycol 1000 base and theobroma oil formulation containing 6% polysorbate 40.