Co-formulation and characterisation of gentamicin-loaded alkyl acrylate cross polymer hydrogel infused with ethanol extract of <i>Tetracarpidium conophorum</i> impregnated on gauze sponge for wound dressing

Margaret O Ilomuanya University of Lagos http://orcid.org/0000-0001-8819-1937
Oluwatobiloba Adeyinka University of Lagos
Chinelo Aghaizu University of Lagos
Ibilola Cardoso-Daodu University of Lagos
Thomas Akhimien University of Lagos
Tolulope Ajayi University of Lagos
Joy Odimegwu University of Lagos

Keywords: hydrogels, wound dressing, Tetracarpidium conophorum, re-epithelisation, antioxidant

Abstract

Background: This study aims to develop a hydrogel containing gentamicin and ethanol extract of Tetracarpidium conophorum (EETC) impregnated gauze to be used as potential wound dressing to promote wound healing via inhibition of growth of microorganisms by gentamicin, and removal of products of inflammation via high radical-scavenging capacity to facilitate wound healing.

Method: A modification of free radical initial polymerisation of the alkyl acrylate polymer was utilised to formulate the gentamicin hydrogel with triethanolamine as the cross linker. The hydrogel membranes were evaluated via Fourier transform infrared and the formulations were assessed for swelling index, skin irritancy and in-vitro release of the gentamicin where kinetics were applied to study drug-release kinetics.

Results: In-vivo wound healing tests and histopathology were performed with Carbopol^® Ultrez 21 exhibiting higher swelling index (97.6–99.6%) due to the availability of more alkyl acrylate polymer chains for cross linking with triethanolamine (TEA), ensuring adequate moisture entrapment in the wound area, thus reducing exudate build up. The presence of EETC enhanced the healing effect in-vivo with 65.7% ± 0.21–73.5% ± 0.10 wound size reduction compared to the control drug which exhibited 63.46% ± 0.37 within fourteen days. Reepithelisation rates were 45–50% and the number of inflammatory cells was 90–300 cell/mm² of field compared to 314 cell/mm² for the control drug.

Conclusion: GH5 hydrogel gauze was found to be most effective in promoting wound healing, exhibiting the highest swelling index, excellent in-vitro drug release and drug content. Transcutol 0.1%w/w, which was present n GH5, increased permeation of gentamicin and EETC. The presence of 0.1% w/w EETC in the hydrogel gauze facilitated the re-epithelisation by 93.7% ± 0.7 and reconstruction of skin tissues on the full-thickness wounds with the thickness of the central region being 2.6–2.9 mm from the epidermis to the dermis thus potentially very useful as a wound dressing.