Development and Evaluation of Floating Microspheres of Anticonvulsant Drug by 32 Full Factorial Design

Abstract

Objectives: Present study was to develop and evaluate gastroretentive microspheres by the solvent evaporation technique. Materials and Methods: Gabapentin and HPMC K100 were used to develop the formulations. Gastroretentive microspheres were developed by the solvent evaporation technique from the preliminary batches of gabapentin microspheres batch FMG3 were selected for factorial study. Results: Factorial batches showed the mean particle size of the floating microsphere formulations for gabapentin (FFMG1-FFMG9) was in the range of 185.63 ± 0.13 to 510.04 ± 0.09 μm. The percentage yields of formulations FFMG1 to FFMG9 for gabapentin ranged from 53.5 ± 0.95 to 96.64 ± 0.42. The buoyancy percentage was calculated for the formulations and found that all formulations could float on dissolution medium for 12 h. The drug loading in gabapentin microspheres was found 65.29 ± 0.46 to 84.3 ± 0.44. The swelling study was found to be 756.34 ± 1.48 to 890.46 ± 0.78 for gabapentin. Batch FFMG6 and FFMC2 showed better drug release 99.1% and 99.25% respectively. The optimized formulation FFMG6 for gabapentin showed an n value 0.8474 and R2 value 0.9965. Conclusion: Optimized formulation obeys Korsmeyer-Peppas release. Scanning electron microscopy images of microspheres were spherical, discrete, and freely flowing. ANOVA for the given formulations showed p value less than 0.0500. The stability study indicated no significant changes in the microspheres. In radiographic images, floating microspheres were retained in the stomach of rabbits for twelve hours.