Abstract

Stephen Olaribigbe Majekodunmi* and Lori Eyituoyo

ABSTRACT

Drugs are often required to be administered over a prolonged period which may necessitate high frequency of administration for those with short half-lives. Controlled drug delivery systems allow therapeutic agents to be delivered at predefined rates, locally or systemically, for a specified period. Microspheres have been developed as carriers for delivering therapeutic agents to their target sites in a controlled release manner. Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), has a short half-life (1–3 hours) and is typically administered 3-4 times daily with subsequent adverse side effects. In the present study, batches of muco-adhesives microspheres of ibuprofen consisting of various combinations of sodium alginate, hydroxypropymethylcellulose and chitosan were prepared by orifice ionic gelation method. Calcium chloride was used as cross-linker and the drug–polymer ratios were varied. Compatibility study between drug and polymer was done by FTIR. Wash off test was carried out to assess muco-adhesive properties. The prepared microspheres were evaluated for particle size, angle of repose, Carr’s index, microencapsulation efficiency, percent drug content, drug release, kinetics and mechanism of drug release. The compatibility study showed no interaction between the drug and polymer. The microspheres were discrete, spherical, free flowing with particle size in the range of 736±0.3 - 797±0.4?m. The encapsulation efficiency was found in the range of 56 ± 0.4 – 70 ± 0.7%. All the microspheres showed good muco-adhesive properties, gave prolonged release which followed first order kinetics with non-fickian release mechanism that was dependent on nature and concentration of polymers. The present study demonstrated that ibuprofen can be considered for mucoadhesive drug delivery containing HPMC and chitosan as mucoadhesive polymers for controlled release of the drug over a period of minimum of 10 hours to maximum of over 12 hours which is however dependent on the concentration and nature of polymers for the gradual reduction of pains and fever.