In vitro Permeability and Bioavailability Enhancement of Curcumin by Nanoemulsion via Pulmonary Administration.

Background: Curcumin has shown considerable pharmacological activity, including anti-inflammatory activity. Nevertheless, the pharmacological effect of curcumin may be limited because of poor water solubility, metabolizing rapidly and systemic elimination. Objective: In the current research, a novel curcumin nanoemulsion (Cur-NE) was developed for improving in vitro permeability and bioavailability via pulmonary administration. Methods: The Cur-NE was prepared by a modified emulsification-evaporation method and its surfac morphology, particles size and distribution, and encapsulation efficiencies of drug in NE were characterized. In vitro transmembrane transport experiment was performed to investigate the transport profile of curcumin across Xenopus alveolar membrane. The pharmacokinetics of Cur-NE in rabbits was evaluated. Results: The average particles size, zeta potential, polydispersity index of Cur-NE were 234.8 +/- 1.08 nm, -19.5 +/- 0.2 mV and 0.10. respectively. Xenopus alveolar membrane was used in the transmembrane transport study, the cumulative amount of curcumin was 6.6% for curcumin suspensions, but nearly 50% for Cur-NE at the time of 8 h (P<0.05). The pharmacokinetic study in rabbits, the absolute bioavailability of curcumin for Cur-NE was 24.11%. Conclusion: Thus, a novel Cur-NE for pulmonary drug delivery was developed for improving in vitro permeability and bioavailability, which can be an alternate to the oral administration.