In vitro and in vivo evaluation of alginate and alginatechitosan beads containing metformin hydrochloride
Purpose: To prepare metformin HCl-loaded alginate (AL) and alginate-chitosan (AL-CS) beads for oral application and to evaluate their in vitro characteristics and in vivo activities.
Methods: AL and AL-CS beads were prepared using ionotropic gelation. The beads were evaluated for particle size, surface morphology, drug encapsulation efficiency (EE) and in vitro drug release. The antidiabetic effects of the beads were evaluated in diabetic Sprague Dawley rats.
Results: The mean particle sizes of AL and AL-CS beads in wet state ranged from 1714 ± 140 to 1850 ± 103 μm. The EE % of AL and AL-CS beads were 33.58 ± 1.56 and 24.11 ± 1.72, respectively, with sustained in vitro drug release of about 93 to 96 % within 8 days in phosphate buffer (PB). Optimized metformin HCl-loaded AL and AL-CS beads showed significant hypoglycaemic effects in diabetic rats over a prolonged period (about 12 h) after oral administration compared to the pure drug (p < 0.05).
Conclusion: Metformin HCl-loaded AL and AL-CS beads for oral application may be useful in prolonging the hypoglycaemic effect of metformin. This is capable of increasing patients’ compliance to the medication.
Keywords: Alginate, Beads, Chitosan, Metformin, Diabetes, In vivo study