Effect of glycerol and dibutyl phthalate on modified natural rubber latex based drug delivery systems.

The work highlights the impact of the incorporation of two pharmaceutical plasticizers viz.; glycerol (GLY; hydrophilic) and dibutyl phthalate (DBP; hydrophobic) on the controlled drug release features of a deproteinised natural rubber latex (DNRL) -based matrix. The effects of the plasticizers on the mechanical properties, glass transition temperature (Tg), water absorption behaviour and porosity of DNRL have been initially investigated. The plasticized membranes have been found to show a hemolysis percentage (HP) of <5 %; confirming its compatibility with human blood. The potential of the modified DNRL membranes to function as drug carriers have been examined with metformin hydrochloride (MET) as a model drug.

Deproteinised natural rubber latex grafted poly(dimethylaminoethyl methacrylate) - poly(vinyl alcohol) blend membranes: Synthesis, properties and application.

Natural rubber latex was initially deproteinised (DNRL) and then subjected to physicochemical modifications to make high functional membranes for drug delivery applications. Initially, DNRL was prepared by incubating with urea, sodiumdodecylsulphate and acetone followed by centrifugation. The deproteinisation was confirmed by CHN analysis. The DNRL was then chemically modified by grafting (dimethylaminoethyl methacrylate) onto NR particles by using a redox initiator system viz; cumene hydroperoxide/tetraethylenepentamine, followed by dialysis for purification. The grafting was confirmed by dynamic light scattering, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The grafted system was blended with a hydrophilic adhesive polymer PVA and casted into membranes. The membranes after blending showed enhanced mechanical properties with a threshold concentration of PVA. The moisture uptake, swelling and water contact angle experiments indicated an increased hydrophilicity with an increased PVA content in the blend membranes. The grafted DNRL possessed significant antibacterial property which has been found to be retained in the blended form. A notable decrease in cytotoxicity was observed for the modified DNRL membranes than the bare DNRL membranes. The in-vitro drug release studies using rhodamine B as a model drug, confirmed the utility of the prepared membranes to function as a drug delivery matrix.