Design of an emulgel and patch based on Opuntia ficus-indica (prickly pear) fruit extract with wound-healing effects

Abstract

The skin is the body's largest organ, serving a vital protective function. Its healing mechanism is divided into four distinct phases: Haemostasis, inflammation, proliferation, and regeneration. This process can be augmented by scar-healing products, particularly those containing polyphenolic compounds such as those found in Opuntia ficus-indica fruit (prickly pear/tuna). In clinical practice, the use of bioactive compounds, such as gelatin patches, is essential for the management of chronic wounds and burns, with treatment selection being dependent on the type of injury and the patient. Emulgels offer a useful cosmeceutical alternative due to their excellent tolerance, moisturising capacity, and accessibility ease of application. Therefore, this project sought to evaluate the wound-healing effect of Opuntia ficus-indica extract incorporated into two distinct matrices: an emulgel and a soft gelatin patch. The methodology employed for extract preparation was as follows: the prickly pear pulp was processed, and the resulting mash was divided into three fractions, each subjected to maceration for seven days using different solvents—Fraction I: mash plus 96% ethanol (1:2 ratio); Fraction II: mash plus water (1:2 ratio) and a mixture of methyl and propyl parabens at 0.1% as a preservative; and Fraction III: mash plus preservative (sodium benzoate at 0.5%). The extracts were initially assessed for efficacy using a coagulation model, and Extracts I and III were subsequently selected for incorporation into the emulgel and patch formulations at a concentration of 20% v/v. These formulations were then subjected to sensory, stability, sensitivity, and wound-healing tests in animal models. Based on the coagulation assay results, the optimal concentration for the emulgel and patch development was determined (Extract Concentration 20% v/v); these final formulations underwent physicochemical and organoleptic testing to assure quality. Subsequently, their efficacy and safety were determined using a dermal sensitivity model in New Zealand white rabbits (adhering to the 12th edition guidelines of the United Mexican States Pharmacopoeia) and a wound-healing model in Wistar rats, and in both models, the formulations proved to be safe and efficacious.