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

Medicinal plants are used exclusively to treat and manage different diseases, especially in poor communities. Castor oil was reported to have potent antibacterial, antifungal, and leishmanicidal activity. This study was conducted to assess the physicochemical, antimicrobial, and in vivo wound healing properties of castor oil-loaded nanogels. Castor oil was extracted from powdered castor beans by solvent extraction using hexane. The extracted castor oil (oil phase ) was combined with Tween 80 (surfactant) and polyethylene glycol (cosurfactant) and was mixed with distilled water as the aqueous phase using the titration method to prepare castor oil-loaded nanoemulsion The optimized nanoemulsion, NM2 was used to prepare nanogels using either carbopol or sodium carboxymethylcellulose as gel base. The extracted castor oil, nanoemulsions, and nanogels were assessed for their physicochemical and antimicrobial properties In vivo wound healing and skin irritation studies were conducted using nanogel formulation BF5. The extracted castor oil, nanoemulsions, and nanogels showed good antimicrobial activity against the test organisms. The nanoemulsions have an average droplet size of 78.71 nm (NM1) and 72.30 nm (NM2) and polydispersity index of 0.402 (NM1) and 0.222 (NM2). The nanogels prepared with sodium carboxymethylcellulose gel base have slightly better physicochemical properties, like spreadability and extrudability than those prepared using carbopol gel base however, they were less stable after one-month storage under room temperature. The wound healing activity of the castor oil-loaded nanogel was comparable to the activity of a marketed product, gentamicin ointment but unlike the ointment it will be more acceptable to the patient due to its non-greasy nature.