In vitro investigation of wound dynamics using Absorbatox® containing organic acid(s)

MSc (Pharmaceutics), North-West University, Potchefstroom CampusThe skin provides an essential protective barrier between the internal tissues and the environment. A wound is defined as a defect or a break in the skin barrier as a result of physical or thermal damage. Wounds may also result due to an underlying medical or physiological condition, which compromises the tissue integrity. Spontaneous wound healing generally occurs due to a defined wound healing process. Modern wound healing treatments are aimed at enhancing the understanding of the various interactions between the cells and mediators, such as cytokines, growth factors and lipid derivatives. Disruption of the normal wound healing cascade results in altered healing ability; creating abnormal, difficult to treat wounds. Normal wound treatment usually involves a specialised wound dressing, which is designed with the aim of improving the ability to maintain a sterile (free of bacterial contamination) environment, as well as eliminating the excess exudate. The development of unique, new treatments for wounds such as burns and abrasions, acne and exuding wounds (typically lower leg ulcers) is in high demand, simply because current available treatments do not address all the issues in wound healing and often a “healed wound” is compromised with poor tissue quality or scarring. The wound healing process involves several different cell types, as well as different soluble mediators where the pH value on and within the wound both directly and indirectly influences the healing process. The pH on the surface of the wound plays an important role in infection control, anti-microbial action, oxygen release, angiogenesis, protease activity, as well as bacterial toxicity. Decreasing wound surface pH with topical applications containing organic acids will provide an environment unfavourable for microbial infestation and growth. Hence, the aim of this study was to formulate three different types of safe and effective wound dressings, which all include a unique combination of Absorbatox® bound to bound to an organic acid (fulvic acid, malic acid and citric acid) to promote an optimal wound healing environment, which optimises moisture control and ensures protection from the risks of maceration, as well as microbial contamination were formulated. Initially, pre-formulation studies were performed determining the compatibility of the Absorbatox® with the different organic acids (fulvic acid, malic acid and citric acid separately) by means of differential scanning calorimetry (DSC), thermal activity monitoring (TAM) and Fourier-transform infrared spectroscopy (FTIR). Thereafter the optimised formula was utilised to formulate a silicone-based gel, hydrogel-based patch and a dry/sachet dressing. Assessment of the cytotoxicity of the active ingredients (separately) and the combination thereof used in the different formulations was performed using in vitro cell cultures, specifically human immortalised keratinocyte (HaCaT) cells. The enhanced fibroblast activity and architecture was also assessed when wound dressings were applied to human skin fibroblast (84BR) cells. The potential cell cytotoxicity was determined by means of methylthiazol tetrazolium (MTT) assay to determine if the active ingredients could be considered safe for the application on human skin and essentially on wounds. Assessment of the wound healing potential of the active ingredients (separately) and the combination thereof used in the different formulations was performed using a cell migration assay, as well as a scratch wound healing assay. Evaluation of the prepared wound dressings with regards to API identification, pH, viscosity, mass loss, particle size, visual appearance and free swelling capacity was performed to determine the stability of the formulations.Master