Associating chitosan and microemulsion as a topical vehicle for the administration of herbal medicines

• Published in: Carbohydrate polymers 2021-03, Vol.255, p.117482-117482, Article 117482
• Main Authors: Oliveira, Denise A.J., Amaral, Juliano G., Garcia, Laryana B., dos Santos, Milena S., Silva, Lorena A.O., Almeida, Maiara P., Gomes, Angélica F., Barros, Danielle R.P., Lopes, Norberto P., Pereira, Gislaine R., dos Santos, Orlando D.H., Ruela, André L.M.
• Format: Article
• Language: English
• Subjects: Adhesiveness; Candida albicans - drug effects; Candida albicans - growth & development; Catechin - chemistry; Catechin - isolation & purification; Catechin - pharmacology; Chitosan; Chitosan - chemistry; Emulsions; Fabaceae - chemistry; Flavonoids - chemistry; Flavonoids - isolation & purification; Flavonoids - pharmacology; Liquid crystal; Liquid Crystals - chemistry; Melaleuca - chemistry; Microbial Sensitivity Tests; Microemulsion; Molecular networking; Molecular Weight; Myristates - chemistry; Plant Extracts - chemistry; Polyethylene Glycols - chemistry; Polysorbates - chemistry; Proanthocyanidins - chemistry; Proanthocyanidins - isolation & purification; Proanthocyanidins - pharmacology; Rheology; Tea Tree Oil - chemistry; Tea Tree Oil - pharmacology; Water - chemistry
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2020.117482

[Display omitted] •Low viscosity chitosan solution (5% w/w) was associated with a microemulsion.•The vehicle with chitosan undergoes a phase transition after water absorption in situ.•The vehicle with chitosan showed improved mechanical properties, as adhesiveness.•The topical formulation incorporated herbal medicines with antifungal activity.•Molecular networking studies indicated expressive amounts of proanthocyanidins. A viscous solution of low molecular weight chitosan (CH) at 5% w/v (10.2 kDa, 75 % deacetylated, 1451 cP at 25 °C) was associated with a microemulsion (ME) that undergoes a phase transition after water absorption in situ (≈28 % w/w), forming a more viscous liquid crystal, which was potentially evaluated as a topical vehicle. The ME was selected from a phase diagram, selecting a composition based on Tween® 80 (52 %), myristate isopropyl (28 %), and the aqueous phase (water and polyethylene glycol 400, 60:40 w/w) (20 %), which was after replaced by CH and herbal medicines (HM). HM are alternatives to treat candidiasis, and Stryphnodendron adstringens shell extract, characterized by molecular networking, and Melaleuca alternifolia Chell essential oil (46 % of terpinen-4-ol), showed in vitro activity against Candida albicans. Associating CH in ME improved the mechanical properties of the topical formulation, as adhesiveness, which is an advantageous feature for the topical treatment of vulvovaginal candidiasis.