The study purposes to evaluate nanocrystalline biopolymeric nanoparticles encapsulating methotrexate and dexamethasone with high biocompatibility, enhanced therapeutic efficacy and reduced toxicity.
Chitosan nanoparticles were prepared by ionic gelation, and Methotrexate (MTX) and Dexamethasone (DEX) were loaded during the preparation and screened for their in vitro efficacy in HEK and RAW264.7 cells, ex vivo and in vivo efficacy.
FTIR confirmed the involvement of phosphoric group of sTPP with amine groups of chitosan and also role of hydrogen bonding involved in the preparation of MTXCHNP and DEXCHNP. Controlled release patterns coupled with diffusion of drug were observed in two different buffers (PBS) at pH 7.4 and pH 5.8. The IC50 for MTXCHNP for HEK was 26.1 μg/ml and 7.7 μg/ml for RAW 264.7 cells. In DEXCHNP, the IC50 was 20.12 μg/ml for HEK and 7.37 μg/ml for RAW264.7 cells. Enhanced uptake of FITC-CHNP by RAW cells indicated internalization of nanoparticles by phagocytosis. The enhanced release of drug at lower pH justified increased cytotoxicity. Negligible ex-vivo hemolysis indicated the higher biocompatibility of the nanoparticles. 
The nanocrystalline biopolymeric nanoparticles were stable, biocompatible and have potential to be administered through i.p. route with minimal toxicity and high efficacy.