Polyoxyethylene Lauryl Ether (Brij-35) and Poloxamer 407–Based Non-ionic Surfactant Vesicles for Dissolution Enhancement of Tacrolimus.

Purpose: This study aimed to develop niosomes using polyoxyethylene lauryl ether (Brij-35) and poloxamer 407 surfactants for dissolution enhancement of tacrolimus, a poorly water-soluble drug for improving oral bioavailability. Methods: Niosomes were prepared using surfactants polyoxyethylene lauryl ether (Brij-35) (Group I), poloxamer 407 (Group II), and hybrid niosomes including both Brij-35 and poloxamer 407 (Group III). A thin film hydration technique was employed for the development of niosomes. Drug-surfactant interactions were examined using FTIR. The entrapment efficiency of niosomes was determined using ultra-centrifugation technique. Vesicle size, PDI, and zeta potential were measured by DLS experiments. Morphological evaluation of vesicles was carried out using SEM microscopy. DSC technique was used to evaluate the thermal behavior of niosomes. In vitro dissolution study of optimized niosomes (F₁-Br35, F₁-PL407, and F₁-BrPL) was performed by dialysis bag method. Results: FTIR studies revealed the compatibility of tacrolimus with used surfactants. Percent entrapment efficiency values were in the range of 88.65 ± 3.13 to 93.67 ± 1.57% for Brij-35-based formulations, 87.83 ± 6.24 to 89.01 ± 5.83% for poloxamer 407, and 90.08 ± 1.12 to 92.81 ± 0.31% for hybrid niosomes. The vesicle size of niosomes was in the range of 282.5 to 622.5 nm. SEM analysis showed an almost spherical shape of optimized formulations (F₁-Br35, F₁-PL407, and F₁-BrPL). DSC analysis demonstrated amorphous form of tacrolimus indicating improved dissolution of tacrolimus. In vitro dissolution of optimized formulations F₁-Br35, F₁-PL407, and F₁-BrPL at pH 7.4 indicated an improved dissolution profile of tacrolimus compared to pure drug aqueous dispersion. Conclusion: Overall, the results of the study concluded that newly developed niosomes could act as a promising approach for enhancing the dissolution profile of tacrolimus and can act as alternate oral carriers. [ABSTRACT FROM AUTHOR]