The objective of the present research was to examine the possible usage of terbinafine loaded hydrogels for vaginal application as part of vaginal candidiasis treatment. Vaginal candidiasis belongs to the most frequent gynecological disorders. Various antifungal drugs are used for its treatment, with Terbinafine being one of them. In this study, new gel formulations were prepared for Terbinafine vaginal delivery. Natural polymers such as chitosan, sodium carboxymethylcellulose, and Carbopol were used for the development of Terbinafine vaginal gels. The developed gels were examined for their viscosity and spreadability, pH and mechanical properties. The most optimal formulations were further evaluated for their in vitro release behavior and antifungal activities. In further, the cytotoxicity and irritation inducing capacity of optimum gel formulations were evaluated. In vitro drug release studies demonstrated that terbinafine release was prolonged whereas anti-candida activity in several species showed the superiority of the gels compared to the marketed product. G-5 and G-8 gels did not cause lysis, hemorrhage and coagulation, therefore, classified as non-irritant. The optimal formulations were also studied for their stability, demonstrating that they were stable for 3 months.

In this study, hydrogels containing azelaic acid were developed using chitosan or HPMC (1-7%) for local treatment of acne vulgaris. Physicochemical properties such as viscosity, pH and mechanical properties were evaluated. In vitro release and ex vivo permeability studies were performed using Franz diffusion cell system. The pH of the hydrogels were highly compatible with the skin pH and varied between 4.38–5.84. The cumulative release percentages of the hydrogels at the end of 6 hours were 65-78%, whereas the marketed product yielded 50% drug release. According to the ex vivo permeability results, azelaic acid accumulated in the skin were found to be 9.38 ± 0.65% (marketed cream), 19.53 ± 1.06% (K3), 10.96 ± 1.91% (H6). The antiacne studies with Cutibacterium acnes revealed that K3 (29.45 ± 0.95) and H6 (32.35 ± 0.15) had higher inhibition zones compared to the marketed cream (24.50 ± 0.90). Additionally, the gels were found to be highly stable as a result of the stability studies for 6 months. Among the hydrogels that were prepared based on experimental findings, K3 (3% Chitosan) and H6 (6% HPMC) represented elevated in vitro release profile, higher permeability and increased antiacne activity. The findings of this research suggest that the developed hydrogels might be an alternative to the marketed product. Graphical Abstract

Nanogels have attracted significant attention in recent years due to their high biocompatibility, controlled release capacity, sensitivity to environmental stimuli, and targeted transport characteristics as drug delivery systems. Chitosan, a natural polysaccharide, is a biopolymer widely used in nanogel formulations due to its positively charged structure, biodegradability, and modifiable functional groups. In this review, the therapeutic applications of chitosan-based nanogels are discussed thoroughly, especially emphasizing in the areas of protein/peptide, antigen, and gene transport. Production methods, chemical modification strategies, transport mechanisms to target cells, and the biological activities of these systems have been evaluated. Chitosan nanogels are promising carrier systems in wide range of areas, including gene therapy, immunotherapy, and the delivery of biological agents, owing to their significant characteristics such as intracellular targeting, endosomal escape, and sustained release. Further studies might enable the translation of these systems into clinical applications.

Modern drug carrier technologies, such as microemulsions with small droplet sizes and high surface areas, improve the ability of low water solubility active ingredients to permeate and localize. The goal of this study was to create microemulsion formulations for wound healing that contained both fusidic acid (FA), an antibacterial agent, and benzocaine (BNZ), a local anesthetic. Studies on characterization were carried out, including viscosity, droplet size, and zeta potential. The drug-loaded microemulsion had a stable structure with –3.014 ± 1.265 mV of zeta potential and 19.388 ± 0.480 nm of droplet size. In both in vitro release and ex vivo permeability studies, the microemulsion was compared with Fucidin cream and oily BNZ solution. According to the drug release studies, BNZ release from the microemulsion and the BNZ solution showed a similar profile (p > 0.05), while FA release from the microemulsion had a higher drug release compared to Fucidin cream (p < 0.001). The microemulsion presented lower drug permeation (p > 0.05) for both active ingredients, on the other hand, provided higher drug accumulation compared to the control preparations. Moreover, according to the results of in vitro wound healing activity, the microemulsion indicated a dose-dependent wound healing potential with the highest wound healing activity at the highest concentrations. To the best of our knowledge, this developed BNZ- and FA-loaded microemulsion would be a promising candidate to create new opportunities for wound healing thanks to present the active ingredients, which have low water solubility, in a single formulation and achieved higher accumulation than control preparations. Graphical Abstract