FORMULATION AND EVALUATION OF INDOMETHACIN LOADED NANOSPONGES FOR ORAL DELIVERY

Nanosponges (NS) loaded sustained release tablet formulations of a non-steroidal anti-inflammatory drug; Indomethacin was successfully developed and evaluated for their pharmaceutical properties. Twelve nanosponge formulations were fabricated by solvent diffusion method by using different ratios of drug and polymers (ethyl cellulose and polyvinyl alcohol). Particle size of all the formulations was in the nano range of 221 to 625 nm and it was found dependent on the polymer concentration. Drug loading and entrapment efficiency were ranged from in 32.2 to 59.4% and 30.1 to 64.8%, respectively. Formulations with an equal proportion of drug and polymer resulted in higher values of drug loading and entrapment efficiency. Percent yield was also found dependent on the relative drug-polymer ratio with the highest value of 51% was achieved for the formulation having the same drug to polymer ratio. SEM results confirmed the formation of spherical and porous structures. Structural analysis by Fourier transform infrared spectroscopy (FTIR), powder x-ray diffraction (PXRD) showed the absence of any interaction between drug and polymer. In comparison to the pure drug, NS formulations showed a linear intrinsic dissolution rate (IDR) profile depicting a controlled release profile. Diffusion studies of NS formulations performed by Franz diffusion cell and dialysis bag methods showed comparable results in terms of precision and linearity of diffusion profile. Tablets prepared from the drug-loaded NS showed acceptable values for hardness, friability and drug content. Release of drug from NS tablets was confirmed as sustained release behavior.