Development and characterization of a nano-drug delivery system containing vasaka phospholipid complex to improve bioavailability using quality by design approach

Background and purpose: Vasicine is a potential bronchodilator and can be used for the effective management of asthma and bronchitis. It has low absorption in the gastrointestinal tract due to its poor solubility thereby low bioavailability. The objective of this research was to develop a novel drug delivery system of vasaka extract to improve its bioavailability by enhancing the solubility and absorption of vasicine. Experimental approach: Vasaka-loaded phytosomes were developed and optimized by thin-layer hydration technique using systematic quality by design approach. Box-Behnken design (32 factorial design) using Design-Expert software was employed to optimize phytosome wherein phosphatidylcholine concentration (X1), stirring temperature (X2), and stirring time (X3) were selected as independent variables. Yield (%), particle size (nm), and entrapment efficiency (%) were evaluated as responses. The optimized phytosome was characterized by studying the surface morphology such as FE-SEM and TEM analysis, thermal characteristics by thermal gravimetric analysis and spectral and diffraction studies by FTIR and XRD analysis and studying the dissolution behaviour of phytosome by in vitro release study. Findings/Results: The percentage yield, particle size, and entrapment efficiency values of the phytosomes were found in the range of 30.03-97.03%, 231.0-701.4 nm, and 20.02-95.88% w/w, respectively. The optimized phytosome showed the zeta potential of -23.2 mV exhibited good stability and SEM and TEM analysis revealed the spherical shape and smooth particles with the uniform particle size distribution of phytosomes. The comparative in vitro drug release study of vasaka extract and phytosome revealed the sustained release characteristics of phytosome which reached 68.80% at 8 h compared to vasaka extract reached a maximum of 45.08% at 4 h. Conclusion and implication: The results highlighted the importance of optimization of formulation development using quality by design strategy to achieve consistent quality of pharmaceutical products.