Formulation and evaluation of mucoadhesive microspheres of simvastatin using a 23 full factorial approach

Abstract

The objective of the current investigation was to optimize and formulate mucoadhesive microspheres loaded with simvastatin utilizing guar gum as the mucoadhesive polymer and stabilizing the particles with magnesium stearate so that the formulation could control the release of the drug thereby reducing its dosing frequency and improving the bioavailability. The microspheres were prepared using emulsion coacervation method and the micromeritic features were evaluated. The yield of all the batches of microspheres was found to be reasonably good ranging from 52.96 % to 75.48 %. The drug loading was found to be 70.46 ± 0.130 to 74.63 ± 0.535 % while the size of microspheres ranged from 13.34 ± 0.092 µm to 17.73 ± 0.217 µm. Swelling study was performed on all the formulation for 24 h and swelling index ranged from 2.95 to 4.27. The particles size of the formulation was found to be 14.04 µm with polydispersity index of 0.701. The mucoadhesion time of the formulation was obtained to be 6 h 19 min. The in vitro release of simvastatin was studied for 12 h and it was found that the microsphere formulation was able to sustain the release of the drug for more than 12 h with 73.2 % drug released at the end of the 12th hour.