Targeted delivery of ursolic acid and oleanolic acid to lungs in the form of an inhaler for the management of tuberculosis: Pharmacokinetic and toxicity assessment

INTRODUCTION: Ursolic acid (UA) and oleanolic acid (OA) are triterpenoids. They are used to treat numerous diseases, including tuberculosis. Combinations of these drugs provide new insight into the management of tuberculosis. The major obstacle is the effective delivery of these drugs to the lungs, which are mainly affected due to M. tuberculosis. A metered-dose inhaler (MDI) was developed to address this issue containing UA and OA, followed by in-vitro and in-vivo evaluation. METHODS: In the present study, MDI formulation was prepared by incorporating UA and OA at the dose level of 120 μg/ml in each actuation. In-vitro evaluation of this MDI formulation was performed to ensure its suitability to deliver UA and OA preciously. With prior approval of IAEC, a pharmacokinetic and acute inhalation toxicity study was conducted using MDI on Wistar rats. RESULTS: The pharmacokinetic study showed an increased biological half-life of UA (9.23±0.104 h) and OA (8.93±0.166 h) in combination therapy. In-vivo toxicity study demonstrated no adverse effects on body weight and vital organs in the treatment group compared with the control group. Histopathology examination of these essential organs showed no abnormalities. Mild alternation in the biochemical and hematological parameters was observed. However, these alterations did not affect the overall health of the animals. CONCLUSION: The present study documents a detailed study for the safety and pharmacokinetics of UA and OA in-vivo for their advanced application in tuberculosis disease.