Influence of carnauba wax on the release profile of ibuprofen implants

Abstract

Pharmaceutical implants are small sterile solid masses usually cylindrical consisting of a highly potent and purified drug intended to be subcutaneously implanted beneath the skin by suitable special injector or by surgical incision for the purpose of providing the continuous release of the active medicament over a prolonged period of time. The purpose of this study was to evaluate the influence of carnauba wax on the release profile of ibuprofen implants. The implants were prepared with gelatin, hydroxypropyl methylcellulose admixture (80:20) and varying amount of carnauba wax (2.5%, 5%, 7.5%) using the solvent casting technique. Another batch of the implant was formulated without the incorporation of carnauba wax. Glycerin was used as the plasticizing agent. The physicochemical properties and the release kinetics of the implants were evaluated. The implant pellets had a similar appearance with minimal batch to batch variation. The mean diameter/thickness of the implants ranged from 2.46±0.10-2.86±0.03 mm, the percentage drug content was ≤96.92±0.12% and the swelling index values were between 2.68±0.01 – 4.87±0.01%. The rate of drug release from the ibuprofen implants was significantly affected by the incorporation of carnauba wax. The higher the amount of carnauba wax incorporated in the formulation, the more retarded the rate of drug release. This can be exploited in the formulation of sustained release ibuprofen implants for the management of chronic diseases such as arthritis.