Hydrogel Based Wound Dressing Material

Abstract

newline Weak mechanical strength of hydrogels in wet condition limits their use for load newlinebearing applications. Their mechanical strength can be raised by grafting them over newlinesome support or by converting them into nanofibrous form. Present thesis is focused on newlinethe preparation of poly (acrylamide-co-acrylic acid) hydrogel grafted over cotton fabric newlineusing two different cross-linkers i.e. PEG and MBAAm for making medicated dressing newlineand nanofibers of hydrogel of poly (acrylamide-co-acrylic acid). FTIR was used to newlineconfirm the insertion of cross-links into the polymer chains. Grafting of uniform newlinehydrogel layer on cotton surface and formation of hydrogel nanofibers were confirmed newlineby using SEM. The average fibre diameter was found to be 275±94.5 nm. newlineSwelling of composite prepared using PEG followed first-order kinetic model newlineat acidic and neutral pH whereas second-order kinetic model at pH 8.5 while that newlineprepared using MBAAm followed second-order kinetic equation at all the pHs studied. newlineThe kinetics of swelling was also governed by Peppas model at all pHs. Release of drug newlinefrom both the composites was studied in phosphate buffers having pH 5.5,7 and 8.5 at newline37±0.1°C and observed that it was fastest in phosphate buffer having pH 7. On fitting newlinedrug release data into different models, it was observed that drug release was diffusion newlinecontrolled and followed Fickian diffusion mechanism in case of composite prepared by newlineusing PEG as cross-linker whereas it was controlled by diffusion as well as chain newlinerelaxation in case of composite prepared by using MBAAm. Mechanical testing using newlineUniversal Testing Machine supported a higher mechanical strength of the hydrogel newlinecomposite as compared to its film. newlinevi newlineSwelling behaviour of Nanofibrous mats was found to be highest at neutral pH newlineand it followed second order kinetics at all pHs. The drug release kinetics was further newlineevaluated and found that it took place by Fickian diffusion (n lt 0.5) and followed newlinesecond order release kinetics.