Gelatin / Sodium Carboxymethylcellulose Hydrogel Microcapsules for Maximum Release of Lidocaine Hydrochloride

Recently, hydrogel drug delivery systems based on natural polymers have received a lot of attention and in this regard, various polymers have been used individually or in combination to achieve more desirable properties. In this study, different concentrations of lidocaine hydrochloride (LidoHCl) with different percentages of gelatin / sodium carboxymethylcellulose were dissolved in water and then dispersed in paraffin medium. Hereby, microcapsules were formed and they were crosslinked with glutaraldehyde finally. Optical and electron microscope images (SEM) showed the formation of spherical microcapsules with slight surface roughness. The formation of crosslinking in the hydrogel and the lack of interaction between the drug and the polymers were investigated and confirmed by infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Evaluation of the effect of independent parameters including glutaraldehyde (GTA), drug and sodiumcarboxymethylcellulose (NaCMC) and their interaction on dependent parameters including swelling percentage, efficiency of drug loading and mean particle size by response surface method (RSM) based on central composite design (CCD) and three replications for the center point was performed. Statistical results showed that the linear effects of independent parameters have the greatest effect on dependent parameters. Based on the statistical analysis, the optimal concentration values for glutaraldehyde 5%, sodium carboxymethylcellulose 10% and drug 40% create the maximum release efficiency of the loaded drug (63.6%). Overall, the results showed that gelatin / carboxymethylcellulose hydrogel microcapsules have the potential to be used as drug carriers.