The Development and Evaluation of Linalool-loaded Liposomal Gel for Oral Candida Infections: Characterization, Skin Permeation, Dermal Retention, and In Vitro Anti-microbial Studies

Abstract

Background: Linalool is a known anti-fungal molecule. It could be a good candidate against oropharyngeal candidiasis if its retention in deeper skin layers, specifically at body tempera-ture, can be extended for a long duration. Aim: We aimed to develop and evaluate a linalool liposome-based mucoadhesive gel. Objective: The objective of this study is to improvise localization in oral mucosa by achieving sus-tained release, ensuring less volatility of linalool and less permeability into the systemic circulation through the mucosa. Methods: The liposomes were prepared by film formation and hydration method and characterized for particle size, polydispersity index, encapsulation efficiency, and morphological characteristics. The lipid carriers were dispersed into the gel matrix of carbopol 934 and HPMC. Results: The gel was characterized and evaluated for in vitro drug release, ex vivo drug permeation through the goat mucosa and ex vivo dermal retention studies. The particle size and entrapment effi-ciency were 201 nm and 79.8%, respectively, with 0.300 PDI. Transmission Electron Microscopy revealed the spherical shape of the particles with a well-identified surface. The gel pH (6.8) was close to oral mucosal pH and had desired adhesiveness and rheological properties. The latter portrayed a slow linalool release (74.75% in 12 hours), low permeation (28.80% in 24 hours) through the mucosa and high retention (45%) compared to simple linalool gel, ensuring its improvised anti-microbial effectiveness against candida. Conclusion: A mucoadhesive liposomal gel offers a suitable medium for ensuring modified release, improved mucosal retention, and the ability to achieve the desired therapeutic effectiveness locally in mucosa for other drugs of volatile nature.