Formulation and Evaluation of Mucoadhesive Microspheres for Intra -nasal Delivery

Intranasal administration is an ideal alternative to the parenteral route for systemic drug delivery. Various conventional dosage forms have been employed for this purpose but they lack to provide the desired bioavailability of the drug due to poor residence time and faster clearance in the nasal cavity. Formulating multiparticulate system with mucoadhesive polymers may provide a significant increase in the nasal residence time. Neostigmine bromide, a cholinesterase inhibitor is conventionally given by oral and i.v. route for the treatment of myasthenia gravis. The aim of the present approach was to overcome the drawbacks of the conventional dosage forms by formulating intranasal microspheres of Neostigmine Bromide with Carbopol 974P NF and HPMC K15 M along with film forming polymer ethyl cellulose by emulsion-solvent evaporation method. The prepared microspheres were characterized for encapsulation efficiency, drug loading, particle size, and surface morphology, degree of swelling, in-vitro mucoadhesion, drug release, in-vivo studies and stability studies. Formulations FN1 and FN5 displayed the best results for carbopol and HPMC based microspheres respectively. Entrapment efficiency was 75.74±0.50 and 70.27±0.61; mucoadhesion was 98.5 and 85.3; and drug release up to 8 h was 87.86 and 84.5 for FN1 and FN5 respectively. In-vitro studies conclude that carbopol based microspheres are Jayapal Reddy Gangadi * et al /International Journal Of Pharmacy & Technology IJPT | Dec-2010 | Vol. 2 | Issue No.4 | 1158-1198 Page 1159 better than HPMC based microspheres for the delivery of neostigmine Bromide. Stability studies indicated that the formulations were most stable at 4°C. In-vivo studies revealed that the formulations FN1 and FN5 showed good bioavailability compared to oral drug administration.