This study investigates pH-sensitive hydrogels based on biocompatible, biodegradable polysaccharides and natural polymers such as chondroitin sulfate and alginate in combination with synthetic monomer such as acrylic acid, as controlled drug carriers. Investigations were conducted for chondroitin sulfate/alginate-graft-poly(acrylic acid) hydrogel in various mixing ratios of chondroitin sulfate, alginate and acrylic acid in the presence of ammonium persulfate and N′,N′-Methylene bisacrylamide. Crosslinking and loading of drug were confirmed by Fourier transform infrared spectroscopy. Thermal stability of both polymers was enhanced after crosslinking as indicated by thermogravimetric analysis and differential scanning calorimeter thermogram of developed hydrogel. Similarly, surface morphology was evaluated by scanning electron microscopy, whereas crystallinity of the polymers and developed hydrogel was investigated by powder X-ray diffraction. Furthermore, swelling and drug-release studies were investigated in acidic and basic medium of pH 1.2 and 7.4 at 37 °C, respectively. Maximum swelling and drug release were detected at pH 7.4 as compared to pH 1.2. Increased incorporation of hydrogel contents led to an increase in porosity, drug loading, and gel fraction while a reduction in sol fraction was seen. The polymer volume fraction was found to be low at pH 7.4 compared to pH 1.2, indicating a prominent and greater swelling of the prepared hydrogels at pH 7.4. Likewise, a biodegradation study revealed a slow degradation rate of the developed hydrogel. Hence, we can conclude from the results that a fabricated system of hydrogel could be used as a suitable carrier for the controlled delivery of ketorolac tromethamine.

Smart and intelligent xanthan gum/pluronic F-127 hydrogels were fabricated for the controlled delivery of atomoxetine HCl. Different parameters such as DSC, TGA, FTIR, XRD, SEM, drug loading, porosity, swelling index, drug release, and kinetics modeling were appraised for the prepared matrices of hydrogels. FTIR confirmed the successful synthesis of the hydrogel, while TGA and DSC analysis indicated that the thermal stability of the reagents was improved after the polymerization technique. SEM revealed the hard surface of the hydrogel, while XRD indicated a reduction in crystallinity of the reagents. High gel fraction was achieved with high incorporated contents of the polymers and the monomer. An increase in porosity, drug loading, swelling, and drug release was observed with the increase in the concentrations of xanthan gum and acrylic acid, whereas Pluronic F-127 showed the opposite effect. A negligible swelling index was shown at pH 1.2 and 4.6 while greater swelling was observed at pH 7.4, indicating a pH-responsive nature of the designed hydrogels. Furthermore, a higher drug release was found at pH 7.4 compared to pH 1.2 and 4.6, respectively. The first kinetics order was followed by the prepared hydrogel formulations. Thus, it is signified from the discussion that smart xanthan gum/pluronic F-127 hydrogels have the potential to control the release of the atomoxetine HCl in the colon for an extended period of time.

The current study aimed to develop pH-responsive hydrogel beads based on sodium alginate (SA) and acrylic acid (Aa), crosslinked in the presence of calcium chloride, for the controlled delivery of ketorolac tromethamine. The hydrogel beads were fabricated using the ionic gelation technique and subsequently characterized for their structural properties, surface morphology, and thermal stability. Additional investigations, including sol-gel analysis, drug loading efficiency, and drug quantification, were conducted to evaluate the physicochemical attributes of the prepared beads. Furthermore, Monte Carlo simulations using the adsorption locator module in Materials Studio were conducted to investigate the adsorption behavior of ketorolac on the SA/Aa hydrogel beads. The negative adsorption energy obtained from the simulations suggested that the interaction between the drug and polymer was both spontaneous and exothermic, indicating a thermodynamically favorable binding mechanism. The pH responsiveness of the beads was evaluated through swelling and drug release studies under different pH conditions (pH 1.2 and 7.4). The results indicated markedly significant swelling and drug release at pH 7.4 as compared to 1.2, thereby confirming the pH-responsive behavior of the formulated beads. The toxicity of the hydrogel beads was evaluated using the Hen's Egg Test on Chorioallantoic Membrane (HET-CAM), which revealed no signs of irritation or toxicity. An in vivo pharmacokinetic study in rabbits further demonstrated that the drug-loaded hydrogel beads achieved higher plasma concentrations of ketorolac tromethamine compared to the drug solution, supporting their potential for improved bioavailability. Hence, the developed SA/Aa-based hydrogel beads exhibited favorable physicochemical, biocompatibility, and pharmacokinetic profiles, making them promising candidates for controlled drug delivery systems.