Dual crosslinked pectin–alginate network as sustained release hydrophilic matrix for repaglinide

Repaglinide, an oral antidiabetic agent, has a rapid onset of action and short half–life of approximately 1 h. Developing a controlled and prolonged release delivery system is required to maintain its therapeutic plasma concentration and to eliminate its adverse effects particularly hypoglycemia. The present study aimed to develop controlled release repaglinide loaded beads using sodium alginate and pectin with dual cross–linking for effective control of drug release. The prepared beads were characterized for size, percentage drug entrapment efficiency, in vitro drug release and the morphological examination using scanning electron microscope. For the comparative study, the release profile of a marketed conventional tablet of repaglinide (Prandin® tablets 2 mg, Novo Nordisk) was determined by the same procedure as followed for beads. The particle size of beads was in the range of 698 ± 2.34 to 769 ± 1.43 μm. The drug entrapment efficiency varied between 55.24 ± 4.61 to 82.29 ± 3.42%. The FTIR results suggest that there was no interaction between repaglinide and excipients. The XRD and DSC results suggest partial molecular dispersion and amorphization of the drug throughout the system. These results suggest that repaglinide did not dissolve completely in the polymer composition and seems not to be involved in the cross–linking reaction. The percent drug release was decreased with higher polymer concentrations. In conclusion, the developed beads could enhance drug entrapment efficiency, prolong the drug release and enhance bioavailability for better control of diabetes.