Tacrolimus-loaded nanostructured lipid carriers for oral delivery-in vivo bioavailability enhancement.

The aim of the present study was to assess the Tacrolimus (TL) loaded nanostructured lipid carrier for enhancement in solubilisation potential, pharmacokinetic parameters and lymphatic distribution profile. The solubilisation potential of TL-NLC was determined via application of dynamic lipolysis models, which simulate the GIT environment and the intestinal conditions. The in vitro lipolysis studies revealed significantly high solubilisation (***p<0.001) of TL-NLCs in aqueous phase (69.3%) in contrast to TL suspension (1.6%) and the results were very well corroborated with in vivo AUC values of the corresponding formulations (R(2)>0.99). The in vivo, lymphatic and organ distribution studies were performed in albino wistar rats. There was marked increase of 7.2 folds in relative bioavailability of TL-NLC in comparison to TL suspension. Furthermore, study findings demonstrated that the lymphatic distribution of TL-NLC was enhanced by 19.25 folds in comparison to TL suspension. The results of dynamic lipolysis, bioavailability, lymphatic and other organ distribution studies confirmed that incorporation of TL in hybrid of lipids with different fatty acid chain length could substantially improve its in vivo prospect.