Formulation and Release Characterisation of Polymer- Blended Alginate Microspheres for an Antidiabetic Drug

Abstract

Alginate microspheres for a highly water soluble antidiabetic drug Metformin hydrochloride was prepared by ionic gelation method and investigated for its various physicochemical and release properties. To prevent a rapid drug release from alginate microspheres in simulated gastro-intestinal media, alginate microspheres were blended with polymers, hydroxy propyl methylcellulose, methylcellulose, chitin and chitosan and evaluated as additive polymers for controlling the drug release. Results indicated that quantity of polymer; gelating agent and time of cross-linking affected the shape, size and release characteristics from the prepared dosage forms. Use of polymers to retard the release of drug was effective. Drug release from the microspheres followed swelling and erosion. The selected batches sustained the release of the drug for more than 8 h. and showed drug entrapment efficiency up to 85%. As the polymer concentration in the formulation increased, the drug release generally decreased. HPMC-blended microspheres swelled but withstood the disintegration, showing an ideal linear release profiles. The zero order release was shown by all the formulations except when chitosan was incorporated. In comparison with chitosan-blended microspheres, HPMC-blended and MC blended alginate microspheres can be easily made and used for controlled drug delivery systems due to convenient process and better controlled drug release.

The Impact of Natural and Synthetic Polymers in Formulating Micro and Nanoparticles for Anti-Diabetic Drugs

“…The prepared microparticles had 85% entrapment efficiency and controlled metformin release for more than 8 hours. Microspheres of alginates blended with hydroxy propyl methylcellulose showed ideal release profile compared to other batches [60].…”