Optimization, characterization, and follicular targeting assessment of tretinoin and bicalutamide loaded niosomes.

Acne vulgaris, a prevalent skin disorder among teenagers and young adults, can have numerous psychological consequences. Topical treatment of acne would be advantageous by reducing the risk of systemic adverse drug reactions. However, the major challenge would be skin penetration through the stratum corneum. Therefore, during this study, tretinoin (TRT) and bicalutamide (BCT) loaded niosomes with follicular targeting potential were fabricated through the thin film hydration technique. Formulation optimization was performed using the Design-Expert software and optimum formulation was characterized in terms of particle size, zeta potential, transmission electron microscopy, drug loading, and differential scanning calorimetry. In vivo follicular targeting was assessed using rhodamine B-loaded niosomes to follow the skin penetration pathways. The results showed that, the optimum formulation was spherical in shape and had an average diameter of 319.20 ± 18.50 nm and a zeta potential of - 29.70 ± 0.36 mV. Furthermore, entrapment efficiencies were 94.63 ± 0.50% and > 99% and loading capacities were 1.40 ± 0.01% and 1.48 ± 0.00% for BCT and TRT, respectively. According to the animal study results, the prepared niosomes with an average diameter of about 300 nm showed significant accumulation in hair follicles. It seems that the designed niosomal BCT-TRT co-delivery system would be promising in acne management with follicular targeting potential.

Nanostructure L-asparaginase-fatty acid bioconjugate: synthesis, preformulation study and biological assessment.

The present study aims to develop a novel L-asparaginase fatty acid bioconjugates and characterize their applicability for intravenous delivery of L-asparaginase. These bioconjugates were achieved by covalent linkage of fatty acids having different chain lengths (C12, C16 and C22) to the native enzyme. To determine the optimum conditions of bioconjugation, the effect of lipid:protein ratios, reaction time and medium composition on enzyme activity and conjugation degree were evaluated. The native and bioconjugates have been characterized by activity, conjugation degree, particle size, and zeta potential. The results showed that bioconjugated L-asparaginase were more resistant to proteolysis, more stable at different pH, and had prolonged plasma half-life, compared to the native form. From partition coefficient study, the modified enzymes showed approximately 15-fold increase in hydrophobicity. Secondary structure analysis using circular dichroism revealed alteration after lipid conjugation. In addition, the Michaelis constant of the native enzyme was 3.38 mM, while the bioconjugates showed the higher affinity to the substrate L-asparagine. These findings indicate that new lipid bioconjugation could be a very useful strategy for intravenous delivery of L-asparaginase.