Abstract

Nanoparticles represent a promising drug delivery system of controlled and targeted drug release. They are specially designed to release the drug in the vicinity of target tissue. Nanoparticles made up of natural, hydrophilic carriers like sodium alginate may have the advantage of producing a stearic hindrance in the systemic circulation. Hence, sodium alginate nanospheres containing methotrexate were prepared by controlled gellification method. The average particle size was found to be 452 nm. The carrier capacity of sodium alginate nanospheres with respect to methotrexate was determined by the drug to polymer ratio, and five different batches of drug loaded nanospheres containing various concentrations of drug were subjected to in vitro analysis by dialysis method. The study on the drug to polymer ratio showed a linear relationship between the concentration of drug and percentage drug loading. The effect of different concentration of Brij-35 on the drug loading was also checked through the batch with lowest drug loading capacity. The in vitro release behaviour from all the drug-loaded batch was found to be pseudo zero order. The ideal batch of nanospheres with highest drug loading and satisfactory in vitro release profile was subjected to stability studies for 60 days at 4o. The stability of drug loaded nanospheres was checked in terms of percentage drug leakage into the storage medium. It has been observed that, there was no much drug leakage into the storage media, when the nanospheres were stored for 1 month. The comparative in vitro cytotoxicity study between drug loaded nanospheres and free drug was carried out using HEP-2 cell lines. The drug bound to nanospheres produced a comparatively better cytotoxic effects at all concentration than the free drug.