In-vitro and In-vivo Evaluation of Niosomal Gel Containing Aceclofenac for Sustained Drug Delivery

Background: Niosomes are non-ionic stable vesicular system, which can accommodate both hydrophobic and hydrophilic drugs. The aim of the present study was to prepare and characterize niosomal gel formulations for sustained delivery of aceclofenac. Aceclofenac is the most widely used anti-inflammatory agent in the treatment of rheumatoid arthritis. It has narrow therapeutic index and short biological half-life. Methods: Aceclofenac loaded niosomes were prepared using reverse phase evaporation technique. The effects of concentration of non-ionic surfactant, cholesterol and concentration of drug on the encapsulation efficiency were studied. The formulations were characterized using different techniques, such as differential scanning calorimetry (DSC), fourier-transform infrared spectroscopy (FTIR), optical microscope and transmission electron microscope (TEM). Selected formulations of niosomes were incorporated into carbopol 934 (1%w/w), sodium alginate (7%w/w), sodium carboxy methyl cellulose (3% w/w), pluronic F127 (20%w/w) and HPMC (3% w/w) gels. The niosomal gel formulations were evaluated for in-vitro drug release and skin permeation. Optimum niosomal gel formulation was evaluated in-vivo using carrageenen-induced rat paw edema test and compared to gel containing the drug alone. Results: TEM analysis confirmed that niosomal samples were spherical in shape and have a definite internal aqueous space. Niosomes of span60 showed higher percent drug entrapment and larger particle size. In-vitro drug release and skin permeation of different gel preparations showed sustained release and enhanced permeation compared to gel formulations containing free drug. Among the niosomal gel formulations, HPMC gel showed the highest release rate of the drug. The in-vivo anti-inflammatory activity of the selected niosomal gel formulation was significantly higher and more sustained than the corresponding non-niosomal gel formulation containing free drug. Conclusion: These results suggest that the niosome-containing gels are promising formulations for sustained local delivery of aceclofenac.