Development and evaluation of ultradeformable vesicles loaded transdermal film of boswellic acid

Abstract Background Boswellic acid (BA), a phytoconstituent obtained from Boswellia serrata, suffers from several limitations after oral administration such as poor systemic absorption, high first-pass metabolism and high frequency of dose requirement, which creates a need to develop an alternative route for drug administration via novel drug delivery formulation. The present research work aims at developing ultradeformable vesicular carriers (transferosomes) for transdermal delivery of boswellic acid to effectively deliver the drug into deeper layers of the skin reaching the target site and thus improving its systemic bioavailability. Ultradeformable vesicles were prepared by thin-film hydration technique, and the formulation was optimized using 32 full factorial design where the amount of lecithin (mg) and concentration of surfactant (%) were considered as independent variables. The formulated boswellic acid-loaded vesicles were incorporated into transdermal film via solvent evaporation technique using the blend of polymers such as starch and HPMC K4M. Results The BA-loaded transferosomes were optimized based on vesicle size (nm) and drug entrapment efficiency (%EE), and the results were found to be 205.4 ± 1.215 nm and 86.39 ± 0.019%, respectively. Transmission electron microscopy (TEM) of optimized batch showed spherical shape of vesicles with identified lamellarity, surface charge of vesicles with high negative value − 15.2 mV that suggests electrostatic repulsion between vesicles, while the formulation showed good deformability index of 11.31 ± 0.032% due to use of Tween 80 as surfactant. In vitro permeation study demonstrated sustained release pattern of 96.53 ± 0.023% up to 24 h. Also, the in vitro drug diffusion study was carried out for transfersomal transdermal film which exhibited enhanced permeation and sustained retention of drug up to 94.71 ± 0.019% for 24 h. Conclusion Accordingly, the research work suggested that the transferosomes provided an efficient nanosized carriers for enhanced permeation of boswellic acid into deeper layers of skin and could successfully exhibit its therapeutic effect.