Formulation and Characterization of Mucoadhesive Microspheres of Aceclofenac

Aceclofenac is an effective analgesic and anti-inflammatory agent with a good tolerability profile through its analgesic and anti-inflammatory properties relief in a variety of painful conditions. The objective of the present study was to prepare the mucoadhesive microspheres of aceclofenac. These were developed to reduce the side effects like gastric irritation and to increase the drug bioavailability, to reduce the frequency of dosing and to enhance patient compliance. The microspheres were prepared by orifice-ionotropic gelation method using polymers such as HPMC (K 15 M, K 100 M, 100 cps), Carbopol 940, Sodium CMC, Guar gum, Sodium Alginate, Ethyl Cellulose, Methyl Cellulose and 10% Calcium Chloride solution. Totally 16 different formulations of aceclofenac were prepared by using the above polymers in 1:1 and 9:1 ratios. Finally, the microspheres were evaluated for various characteristics like drug content, encapsulation efficiency, percent mucoadhesive strength and the in vitro release was evaluated for 10 hrs. The Microspheres were institute to be detached, spherical, free-flowing, and of the monolithic matrix type. The microspheres were uniform in size, with a mean size of 73.21 to 98.35µm. The microencapsulation efficiency was in the range of 68% to 86%. Microspheres with a coat consisting of sodium alginate and a mucoadhesive polymer exhibited good mucoadhesive properties in the Ex Vivo wash-off test. Aceclofenac release from the microspheres was slow and depended on the composition of the coat. Release followed zero-order kinetics (R2 =0.971). The order of decreasing release rate observed with various microspheres was F9 > F7 > F1 > F2 > F3 > F10 > F11 > F4 > F12 > F14 > F13 > F5 > F8> F6 > F16 > F15. The differences in the drug release characteristics of various microspheres are due to the differences in the porosity of the coat formed and its solubility in the dissolution fluid.