RESUMEN
In recent years azo functionalized polymeric hydrogels are very interesting; it is due to their promising applications in various fields especially in the colon drug delivery. 4-Hydroxyphenylazo-3-N-(4-hydroxyphenyl) maleimide (HPM) was synthesized and used for development of hydrogels by free radical polymerization with acrylamide (Am) and N,N-methylene bis acrylamide. Synthesized poly(Am-co-HPM) (PAH) hydrogels were used for encapsulation of 5-fluorouracil (5-FU) an anticancer drug. Structural, thermal, morphological and drug distribution of PAH hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction techniques, respectively. Maximum percentage of encapsulation efficiency i.e. 78.25±1.3 was observed for AZ1 PAH hydrogels. 5-FU release studies were performed by in vitro method in simulated gastro intestinal fluids (pH 1.2 & 7.4). To support the 5-FU release mechanism from PAH hydrogels, swelling and deswelling kinetics were studied in doubly distilled water.
RESUMEN
Biodegradable sodium alginate-g-poly (vinyl caprolactam) synthesized by graft copolymerization of N-vinyl caprolactam (VCL) on to sodium alginate (NaAlg) via free radical initiation mechanism using a redox initiation system. Grafting (%), efficiency (%), and conversion (%) were all found to depend on the content of potassium persulfate (KPS), VCL reaction temperature and time. The maximum % of grafting was ascertained to be 251 at the optimum conditions of 65 oC reaction temperature, 180 min of reaction time, 1.1098X10-3 mol of KPS and 7.1844X10-3 mol of VCL. Evidence of graft copolymerization was obtained by fouriertransform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Further, graft copolymer was used for preparation of microgels (MGs) using Ca+2 as a crosslinking agent. SEM results showed that the MGs are spherical in structure with smooth surface. The effects of pH and temperature on the swelling behaviour of MGs were studied and ascertained that they were sensitive to both pH and temperature. 5-FU drug was successfully loaded in to these MGs and encapsulation efficiency was found 84%. The release of 5-FU was systematically investigated as a function of temperature, pH, amount of crosslinker and % of drug loading concentration. The results indicate that the responsive MGs have the potential to be used as an effective pH and temperature controlled delivery of 5-FU for more than 12 h.
RESUMEN
Interpenetrating polymer network [IPN] microspheres of acrylamide (AAm) grafted on Carboxymethyl cellulose (CMC) and Sodium alginate (NaAlg) microspheres were prepared by water-in-oil (W/O) emulsion method. These microspheres were loaded with Triprolidine hydrochloride monohydrate (TPH) and cross-linked with glutaraldehyde. The prepared microspheres were characterized by Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM) and Laser particle size analyzer. DSC thermo grams of TPH loaded AAmg- CMC/NaAlg IPN microspheres confirmed the molecular level distribution in the polymer matrix. SEM of the microspheres suggested the formation of spherical particles. Swelling experiments on the microspheres provided important information on drug diffusion properties. Release data have been analyzed using an empirical equation to understand the nature of transport of drug containing solution through the polymeric matrices. The controlled release characteristic of the matrices for TPH was investigated in pH 7.4 media. Particle size and size distribution of the microspheres was studied by laser light diffraction particle size analyzer. Drug was released in a controlled manner upto 12 h.