Formulation and evaluation of mucoadhesive microspheres of ranitidine hydrochloride using chitosan and sodium carboxy methyl cellulose as polymers

The aim of the present research is to develop gastro retentive mucoadhesive microspheres of ranitidine hydrochloride employing chitosan and sodium carboxy methyl cellulose as polymers by simple emulsification phase separation technique. Different batches of mucoadhesive microspheres (MMR-1 to MMR-10) were prepared by varying the polymer ratios and concentration of cross linking agent (glutaraldehyde). The best formulations were selected based on the percentage yield, drug loading and entrapment efficiency. With the increase in concentration of glutaraldehyde, drug loading and entrapment efficiency were increased which may be due to stabilizing effect of the cross linking agent on the droplet, thereby preventing the drug loss during preparation. The formulation MMR-6 was selected as an ideal formulation based on mucoadhesion and in vitro drug release tests. In vitro drug release was carried out in simulated gastric fluid (50mL of 0.1N HCl) for 14h by dialysis technique. The shape of microspheres demonstrated by light microscope was spherical. The drug release from the ideal formulation (MMR-6) followed Higuchi model than the zero order and first order kinetic models. Korsmeyer- Peppas model analysis indicated that the drug release followed non-Fickian transport mechanism.