A New Approach to Ex Vivo Permeation Studies in In-Situ Film-Forming Systems

Newfangled Topical Film-Forming Solution for Facilitated Antifungal Therapy: Design, Development, Characterization, and In Vitro Evaluation

Luliconazole is a broad-spectrum topical antifungal agent that acts by altering the synthesis of fungi cell membranes. Literature suggests that the recurrence of fungal infection can be avoided by altering the pH of the site of infection. Studies have also suggested that fungi thrive by altering skin pH to be slightly acidic, i.e., pH 3-5. The current study is aimed to design, develop, characterize, and evaluate an alkaline pH-based antifungal spray solution for antifungal effects. Luliconazole was used as an antifungal agent and an alkaline spray was formulated for topical application by using Eudragit RS 100, propylene glycol (PG), water, sodium bicarbonate, and ethanol via solubilization method. Herein, sodium bicarbonate was used as an alkalizing agent. Based on DSC, FTIR, PXRD, scanning electron microscopy (SEM), and rheological analysis outcomes, the drug (luliconazole) and polymer were found to be compatible. F-14 formulation containing 22% Eudragit RS 100 (ERS), 1.5% PG, and 0.25% sodium bicarbonate was optimized by adopting the quality by design approach by using design of experiment software. The viscosity, pH, drying time, volume of solution post spraying, and spray angle were, 14.99 ± 0.21 cp, 8 pH, 60 s, 0.25 mL ± 0.05 mL, and 80 ± 2, respectively. In vitro drug diffusion studies and in vitro antifungal trials against Candida albicans revealed 98.0 ± 0.2% drug diffusion with a zone of inhibition of 9 ± 0.12 mm. The findings of the optimized luliconazole topical film-forming solution were satisfactory, it was compatible with human skin, and depicted sustained drug release that suggests promising applicability in facilitated topical antifungal treatments.

Herpes Labialis: A New Possibility for Topical Treatment with Well-Elucidated Drugs

Mucocutaneous infections caused by Herpes simplex virus (HSV-1 and HSV-2) are characterized by the appearance of vesicles that cause pain and embarrassment to the carrier. The standard treatment is based on the use of antivirals in gels or ointments, however, relapses are common. Local anesthetics decrease the pain caused by the lesion, in addition to showing antiviral properties. Semi-solid form facilitates application and its transformation into a thin film favors the maintenance of the formulation in place, with a more discreet final aspect. The objective of this study was to develop and evaluate formulations containing anesthetics for the treatment of cold sores. For this purpose, two semi-solid film-forming formulations were developed and evaluated, containing HPMC K100, lidocaine (LIDO) and prilocaine (PRILO) combined with adjuvants, in the presence (F1T) or not (F1) of the absorption promoter Transcutol®. The mixture of PRILO and LIDO resulted in the formation of a eutectic mixture (EM), essential for penetration of drugs into the skin. The quantification of drugs was performed by HPLC (High Performance Liquid Chromatography), and Transcutol® did not influence the release of drugs from the formulation. The bioadhesiveness of the formulation was evaluate and the drugs did not impair the adhesive potential of the polymers used. The formulations were evaluated in vivo for skin irritation and did not show any negative sign on macroscopic examination. The in vivo efficacy test proved the anesthetics' ability to decrease the lesions caused by HSV-1. Thus, the proposed formulations proved to be good alternatives to the treatment of oral lesions caused by HSV-1.