Nanosuspension enhances dissolution rate and oral bioavailability of Terminalia arjuna bark extract in vivo and in vitro

Abstract

Objective: To enhance the dissolution rate and oral bioavailability of Terminalia arjuna bark extract by formulating its nanosuspension. Methods: Nanoprecipitation approach was used for the formulation of nanosuspension using polysorbate-80 as a stabilizer. The formulated nanosuspension was assessed for particle size, polydispersity index, zeta potential value and for in vitro dissolution study. Oral bioavailability studies were carried out in Wistar male albino rats by administering a single dose (50 mg/kg. b. wt) of the formulated nanosuspension and coarse suspension. The storage stability of the formulated nanosuspension was determined after three months of storage at room temperature and under the refrigerated condition. Mutagenicity assay was carried out to evaluate the toxicity of the formulated nanosuspension using two mutant strains (Salmonella typhimurium TA100 and Salmonella typhimurium TA98). Results: The mean particle size of the formulated nanosuspension was 90.53 nm with polydispersity index and zeta potential values of 0.175 and -15.7 mV, respectively. Terminalia arjuna nanosuspension showed improved dissolution rate and 1.33 fold higher oral bioavailability than its coarse suspension. The formulated nanosuspension also showed better stability under the refrigerated condition and was non-mutagenic against both strains. Conclusions: Our study demonstrates that nanosuspension technology can effectively enhance the dissolution rate and oral bioavailability of Terminalia arjuna bark extract.

Keywords

• terminalia arjuna; nanosuspension; bioavailability; stability; toxicity; polysorbate-80