Determination of Rate of Release of Dye from the Hydrogels using Spectrophotometer Studies

Abstract

Introduction: The main aim of the research was to determine the rate of release of dye from the hydrogels using
spectrophotometer studies. Materials and Methods: The gelatin (GE)-polyethylene glycol (PEG) composite
hydrogels were prepared by the simultaneous method. Several combinations of GE-PEG composite hydrogels
were prepared with methylene blue (MB) dye in it. The components were thoroughly mixed by stirring the
solution during preparation to make them homogeneous. Results and Discussion: The effects of glutaraldehyde,
GE, and PEG variation on dye release with different hydrogel composition samples investigated. The results
showed that as the concentration of cross-linking agent increases from 5 ml to 15 ml, absorbance of the sample
decreased from 0.43 to 0.42 in demineralized water and 0.47 to 0.42 in 0.1M HCl due to decrease in the pore
diameter of the sample, and with increased GE composition from 2.0 g to 4.0 g, absorbance of the sample also
increased. Conclusion: The increased amount of GE decreased the intactness of the matrix, allowing the greater
release of MB. The hydrophilic nature of PEG increases the interaction with the solvent which causes swelling of
the microvoids, thus resulting in the high release of MB.