Biocompatible hydrogels for the controlled delivery of anti-hypertensive agent: development, characterization and in vitro evaluation

Abstract

The aim of the present exploration was to develop novel pH-sensitive cross-linked Gelatin/Polyvinyl pyrrolidone hydrogels using different ratios of both the polymers and to investigate the effect of polymers and degree of crosslinking on dynamic, equilibrium swelling and invitro release pattern of the model drug (captopril). Grafting polymerization technique was used for the preparation of these hydrogels using glutaraldehyde as crosslinking agent. These polymeric materials were then used as model systems to envisage various important characterizations like FTIR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction) and scanning electron microscopy (SEM). Phosphate buffers of pH 1.2, 6.5 and 7.5 were used for swelling and invitro drug release profile investigation. Different parameters like swelling analysis, porosity, sol-gel analysis, average molecular weight between crosslinks (Mc), solvent interaction parameter (χ), volume fraction of polymer (V 2,s) and diffusion coefficient that affects the drug release behavior were also determined. Higher swelling and release was observed at lower pH values. FTIR spectra showed interaction between gelatin and polyvinyl pyrrolidone and successful formation of cross-linked structure. Pulsatile drug release study showed the controlled delivery of model drug. The release of drug occurred through non-fickian diffusion or anomalous mechanism. Aforementioned characterizations reveal successful formation of copolymer. pH sensitive swelling ability and drug release behavior suggest that the rate of polymer chain relaxation and the rate of drug diffusion from these hydrogels are comparable which also predicts their possible use for site specific captopril delivery.

Features of Structure and Properties of pHEMA-gr-PVP Block Copolymers, Obtained in the Presence of Fe2+

“…Hydrogels are characterized by a high sorption capacity for low molecular weight compounds and permeability for liquids and gases, which is a prerequisite for their use in various fields of science and technology [ 3 , 4 , 7 , 9 ]. Those materials have acquired special practical application in medicine and biotechnology [ 9 , 10 , 11 , 12 , 13 ]. Due to their structure, which resembles the structure of living tissues, hydrogels are characterized by good biocompatibility, which allows them to be used in direct contact with a living organism [ 14 , 15 , 16 ].…”

Determination of hydrogel swelling factors by two established and a novel non‐contact continuous method

“…Other medical applications are implantable in vivo expanders, 5 products to improve wound healing processes, 6 and drug delivery systems 7,8 . The good biocompatibility of most hydrogels also minimizes side effects and prevents allergic reactions or immune rejection, 9,10 which also makes the transparent hydrogels interesting as replacement materials for the natural human lens in ophthalmology 11–13 . Furthermore, hydrogels are attractive materials in the contact lens industry 14 .…”

Targeted Delivery of Methotrexate through pH-sensitive Hydrogel: To Treat Colon Pathology

“…The reason could be that the concentration of the PVA polymer is lesser in quantity, so will not affect the drug unloaded hydrogel FTIR spectra [44] and most functional chemical groups occurring in the same peak regions and also have no cross-linker in drug loaded samples (A1-A6), so they may only overlap upon each other. While the FTIR spectra of the drug loaded hydrogel graph 4.34 may also show no any significant variation from the spectra of graph 4.33, because the methotrexate in water insoluble, so may not interact with the water soluble polymers (either gelatin or PVA), these can be correlated with observations of [14].…”

“…The hydrogel in other words are also called as intelligent or smart gel [13]. They are actually three-dimensional structures, which have polymeric networking and are hydrophilic in nature [14].…”