The structural, morphological and thermal properties of grafted pH-sensitive interpenetrating highly porous polymeric composites of sodium alginate/acrylic acid copolymers for controlled delivery of diclofenac potassium

Abstract

In present investigation new formulations of Sodium Alginate/Acrylic acid hydrogels with high porous structure were synthesized by free radical polymerization technique for the controlled drug delivery of analgesic agent to colon. Many structural parameters like molecular weight between crosslinks (M c), crosslink density (M r), volume interaction parameter (v 2,s), Flory Huggins water interaction parameter and diffusion coefficient (Q) were calculated. Water uptake studies was conducted in different USP phosphate buffer solutions. All samples showed higher swelling ratio with increasing pH values because of ionization of carboxylic groups at higher pH values. Porosity and gel fraction of all the samples were calculated. New selected samples were loaded with the model drug (diclofenac potassium).The amount of drug loaded and released was determined and it was found that all the samples showed higher release of drug at higher pH values. Release of diclofenac potassium was found to be dependent on the ratio of sodium alginate/acrylic acid, EGDMA and pH of the medium. Experimental data was fitted to various model equations and corresponding parameters were calculated to study the release mechanism. The Structural, Morphological and Thermal Properties of interpenetrating hydrogels were studied by FTIR, XRD, DSC, and SEM.

Development andIn-VitroEvaluation of pH Responsive Polymeric Nano Hydrogel Carrier System for Gastro-Protective Delivery of Naproxen Sodium

“…is reduction in gel fraction was observed because of the fact that when the concentration of the polymer increased, less cross linking took place that resulted in increase in un-reacted contents. Similar ndings were reported in a study of Jalil et al [30] where they synthesized the copolymer of sodium alginate and acrylic acid through free radical polymerization technique. ey also reported the reduction in gel fraction with increase in concentration of polymer.…”

“…A er the speci ed time, slices of hydrogel were taken o from the water and subjected to drying for 72 hrs at 50°C. By using the Equations (5) and (6), Sol fraction and gel fraction was calculated [30], where = initial mass, = mass a er extraction,…”

The Structural, Crystallinity and Thermal Properties of pH responsive Interpenetrating Gelatin/Sodium Alginate Based Polymeric Composites for the Controlled Delivery of Cetirizine HCl

“…DC is dependent on the amount and nature of chemicals in the polymer. The following equation was used for the determination of DC: 20 (3)…”

“…The gel fraction was measured by taking into consideration the initial dry weight (W o ) and extracted dry gel (W i ) weight using the following equation. 20,26…”

“…Three methods were used to measure the amount of CTZ HCl loaded in the Ge/SA hydrogels. 20 The equation used to determine the amount of cetirizine loaded by weight method is shown belowr:…”