Generation of sustained release chitosan nanoparticles for delivery of ketorolac tromethamine: a tubular microreactor approach

In-vitro and in-vivo evaluation of biocompatible polymeric microgels for pH- driven delivery of Ketorolac tromethamine

The aim of the current study was to prepare glutamic acid crosslinked poly(itaconic acid/methacrylic acid) microgels for pH-responsive delivery of ketorolac tromethamine, using aqueous free radical polymerization technique. The polymerization of polymer with monomers was carried out by a crosslinking agent N', N'-methylene bisacrylamide in the presence of initiator ammonium persulfate. The prepared microgels were characterized for structure, surface morphology, thermal stability, and crystallinity. Similarly, studies such as sol-gel analysis, drug loading, and polymer volume fraction were performed for the fabricated microgels. The pH-sensitivity of the developed microgels was investigated at three different pH values i.e., pH 1.2, 4.6, and 7.4 by swelling and in-vitro drug release studies. Maximum swelling and drug release were found at pH 7.4 as compared to pH 1.2 and 4.6, which indicated the pH-sensitive nature of the prepared microgels. The toxicity of the prepared microgels was evaluated by cell line and HET-CAM test, which demonstrated no toxic effect of the prepared microgels. In-vivo study was carried out on rabbits and high plasma concentration was reported for the drug loaded microgels as compared to drug solution and commercial product Keten. Hence, the prepared microgel system could be employed as an excellent carrier for the controlled drug delivery system.

Preparation of pH-Responsive Hydrogels Based on Chondroitin Sulfate/Alginate for Oral Drug Delivery

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.