Evaluation of the Physicochemical, Antimicrobial and in vivo Wound Healing Properties of Castor Oil-Loaded Nanogels

Abstract

The extent of suppression of certain infections by different essential oils depends on the type of essential oil, its concentration, and the implicated pathogen. 5 Nanoemulsions are clear, thermodynamically stable, oil-water dispersions stabilized by the interfacial coating of surfactant molecules with droplets smaller than 100 nm. 6,7 They are colloidal systems that are made up of an aqueous phase and an oil phase, that are stabilized with surfactants and at times by adding auxiliary surfactants. They have dispersed phase droplets that are very small (20-500 nm), interphase surfaces that are large, as well as, low surface and interfacial tension. 8,9 As a result of these, nanoemulsion enhances the absorption rate and eradicates absorption variability, as well as, assists in solubilizing lipophilic drugs, thereby enhancing their bioavailability. 9 Direct topical application of nanoemulsion is deterred and the skin permeation profile is modified due to its low viscosity. These problems can be solved by incorporating a nanodispersion into the polymer solution to form an in situ nanoemulgel. A hydrophobic drug is incorporated in the oil cores of nanoemulgel, while the hydrogel cross-linked network entraps the droplets of emulsion. 8 Nanoemulgel has enhanced the topical efficacy of many, hitherto poorly permeable drugs. It also solves the problem of hydrophilicity of hydrogels, which limits the applications for the delivery of hydrophobic drugs. 8 Wounds are injuries inflicted on living tissue that distorts its typical anatomical structure and activity. They occur as a result of physical, chemical, thermal, microbial, or immunological injury to the tissue. Irrespective of its cause and kind, wounds can inflict harm on the tissue and distort its surrounding environment. The injury can affect the skin epithelial layer's integrity and can also extend into the subcutaneous tissue disrupting associated structures like tendons, muscles, and nerves.