Tenoxicam-loaded polymeric micelles material: Formulation, optimization, and evaluation

Abstract

The objective of the current study was to encapsulate Tenoxicam a poorly soluble drug within self-assembled polymeric micelles created from amphiphilic block copolymer poloxamer 407 to enhance its solubility and thus increasing oral bioavailability. Thin-film hydration technique was adapted in preparation of Tenoxicam loaded polymeric micelles based on different ratios of copolymer poloxamer 407 (ranging from 1:5 up to 1:90), selection of the best micellar formula was based on the values of entrapment efficiency (EE%), particle size (PS), polydispersity index (PDI), and rate of in vitro drug release, then lyophilization was done for selected formula. Prepared micellar solutions (PM1-PM10) were characterized and the best formula PM6 was chosen according to good EE% (84.05%), smaller particle size (33.07 ± 2.23 nm), lower PDI value (0.155), and higher in vitro drug release (81.43% ± 0.048), which further lyophilized and subjected for powder characterization. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) indicated that TNX was encapsulated in polymeric micelle core, due to the disappearance of a characteristic peak of TNX. Saturated solubility of PM6 lyophilized powder showed an increase in aqueous solubility (122 times) compared with pure drug, while transmission electron microscopy (TEM) showed the polymeric micelles in images with a spherical structure, smooth surface, uniform particle size, and homogeneous distribution in an aqueous medium. It was concluded that the prepared amphiphilic copolymer micelles loaded with TNX exhibited significant improvement in drug solubility and consequently may enhance oral bioavailability and suggested to be used to prepare solid oral dosage form as an alternative to the marketed one with lower dose size and reduce drug side effects.