Development and manufacture of poly vinyl alcohol and poly methyl vinyl ether alt maleic anhydride hydrogels as wound dressing

Wounds are breaks in the tissue due to physical or thermal damage. An acute wound can take anywhere from 8-12 weeks to fully heal whereas a chronic heal can take considerably longer. Healing occurs through several overlapping stages of haemostasis, inflammation, proliferation and maturation [1]. To aid the healing process and prevent further damage to the area the wound dressings tend to be used. These can be made from a variety of materials like films, foams, hydrogels and hydrocolloids. For a hydrogel to be used as for wound healing it needs to be: • easily removable without causing trauma • produced in a sterile form • physically strong even when wet • biocompatible [2] PVA has been used in repairing and regenerating tissues and organs and has shown good hydrophilicity, biodegradability and biocompatibility [3]. To aid with the thermo-gelling properties and improve mechanical strength and adhesiveness of the hydrogel, GANT will be used. PVA-GANT hydrogels are fully transparent which allows for visual monitoring of the wound without removal [4]. Hydrogels are usually described by their swelling capacity which can be established by how much water and aqueous liquids the gel can imbibe. Although this can be determined by a variety of factors, cross-linking density of the polymers has shown to be the most important parameter. In addition to this, hydrogels for bio-applications are required to have good mechanical properties i.e. high in strength, elasticity and mucoadhesiveness. However, as these parameters contradict each other, a compromise between the hydrophilicity and strength needs to be achieved. Autoclaving can be used to enable cross-linking between the polymers without the need for aids which can be toxic. Hydrogels formulated in this way tend to be sterile, antimicrobial and biocompatible [5] Quality by Design (QbD) is a systematic approach to product development that focuses on risk-based science and gaining process understanding whilst minimise time and resources through exploring predefined objectives [6]. Here, it will be used to assess how the critical quality attributes (CQAs) polymer ratio, total polymer concentration and critical process parameter (CPP) autoclaving time can impact physicochemical properties (swelling degree, and mechanical properties) and pharmaceutical aspects (drug release profile) of the hydrogel produced. Design of Experiment will be used to gain a better understanding of the process through a minimal number of experiments by utilising JMP Pro 13 to propose a Response Surface Design and explore the CQAs and CPP mentioned above. Finally, the pore structures of the hydrogels will be assessed with SEM, the type of water imbibed will be determined by DSC and TGA and the cross-linking density will be determined by FTIR before they are developed in their final dosage forms. References: [1]Kalarikkil, N et al. (2016) Nanomedicine and Tissue Engineering pp. 495 [2] Dhivya, S et al. (2015) Biomedicine (Taipei) 5(4) pp. 24-28 [3] Jiang, S et al. (2011) Mech. Behaviour of Biomed. Materials 4. Pp.1228-1233 [4] Moreno, E et al. (2014) International Journal of Pharmaceutics pp. 1-9 [5] Khutoryanskiy VV et al. (2016) RSC Advances, 6, 55211 [6] Sangshetti, J et al. (2017) Arab Journal of Chemistry 10(2) pp. s3412-s3425