Whole whey stabilized oleanolic acid nanosuspension: Formulation and evaluation study

Oleanolic acid (OA), an important natural product, bears variety of pharmacological actions of interest; but its use in the modern therapy is limited due to low water solubility and dissolution rate. The main objective of this study was to develop the lyophilized oleanolic acid nanosuspension (OA-NS) using whole whey. The prepared OA-NS was evaluated by using FTIR, TLC, DLS, SEM, TEM, AFM, DSC, PXRD, dissolution and stability study. To determine the efficacy of OA-NS over free OA in terms of dissolution rate, the in vivo antidiarrheal study was carried out in male Wistar albino rats. The prepared OA-NS particles revealed its nearly spherical shape with mean particle size less than 100 nm. In compatibility study, no possible irreversible molecular interactions were found. The dissolution rate of OA in the form of OA-NS was found to be better as compared to free OA possibly due to transformation of crystalline state to amorphous also supported by in vivo antidiarrheal study. The results demonstrated that the whole whey stabilized OA-NS provides novel approach to increase the dissolution rate along with long term stability to OA which can also be potentially useful for the other poorly water soluble drugs.