In vivo anti-psoriatic activity, biodistribution, sub-acute and sub-chronic toxicity studies of orally administered methotrexate loaded chitin nanogel in comparison with methotrexate tablet.

The anti-psoriatic efficacy of orally administered methotrexate loaded chitin nanogel (MCNG) was evaluated (two doses- 2.715 mg/kg and 5.143 mg/kg) and compared against orally administered methotrexate tablet MTX (5.143 mg/kg). MCNG at both dose levels of 2.715 mg/kg and 5.143 mg/kg exhibited significant anti-psoriatic activity which is very much comparable with MTX, caused normalization of histological features and inflammatory score associated with induced psoriasis. Biodistribution studies revealed the presence of drug in serum and in vital organs at all the three cases with highest amount in MCNG at 5.143 mg/kg dose, followed by MTX tablet and are lowest in MCNG at 2.715 mg/kg dose. MCNG at the highest dose of 5.143 mg/kg caused liver, lung and kidney toxicities on sub acute toxicity studies and MTX tablet was found to be toxic on liver and lung on sub chronic toxicity studies. MCNG 2.715 mg/kg was found to be safe on both sub acute and sub chronic administrations, suggesting that it can provide sufficient serum and tissue level of methotrexate necessary to clear psoriatic lesions, without inducing systemic toxicity and expected to be a better alternative for orally administered conventional methotrexate tablet for patients who need systemic medications for psoriasis.