Development and characterization of albendazole-loaded bilosome and liposome formulations, and evaluation of thier solubility and intestinal absorption properites

Albendazole (ABZ), a benzimidazole anthelmintic drug, possesses limited aqueous solubility and low oral bioavailability, limiting its clinical activity. The present study aimed to develop and optimize ABZ-loaded bilosomes (BLZ) and liposomes (LPZ) with comparative evaluation to enhance dissolution and intestinal permeability. Bilosomes were developed by thin-film hydration and optimized by central composite design with phosphatidylcholine (PC), sodium taurocholate (STC), and sonication time as important variables. Liposomes of PC with cholesterol served as a control. BLZ formulation maximized shown favorable physicochemical characteristics, including 204.8 nm particle size, 0.218 PDI, –40.9 mV zeta potential, and good entrapment efficiency (87.46%) favoring stability and efficient drug loading. The liposomes exhibited enlarged size and decreased negative surface charge. DSC and XRD confirmed ABZ amorphization in vesicles, and FTIR established physical encapsulation. Spherical multilamellar vesicles were exhibited by SEM and TEM measurements. In vitro release studies showed improved release of BLZ compared to LPZ and ABZ individually, i.e., BLZ > LPZ > ABZ for both pH 1.2 and pH 7.4. The analytical spectrophotometric method proved accurate and sensitive after validation. Single-pass intestinal perfusion (SPIP) in vivo in rat showed improved permeability for vesicular preparations compared with ABZ but no statistically significant difference between LPZ and BLZ. Overall, bilosomes enabled enhanced dissolution and positive predicted absorption of ABZ, making their application more favorable as an oral drug delivery system for weakly soluble drugs. Keywords: Albendazole; Bilosomes; Liposomes; Oral drug delivery; Solubility enhancement; Intestinal permeability; SPIP; Nanocarriers.