Development of pH sensitive nanoparticles for intestinal drug delivery using chemically modified guar gum co-polymer

ABSTRACT

The aim of the research work was to chemically modify guar gum[GG] as a pH sensitive co-polymer and formulating intestinal targeting ESO nanoparticles [NPs] using the synthesized co-polymer. Poly acrylamide-grafted-guar gum [PAAm-g-GG] co-polymer was synthesized by free radical polymerization. Chemical modification of PAAm-g-GG by alkaline hydrolysis results in formation of a pH-sensitive co-polymer. The effect of GG and acryl amide [AAm] on grafting was studied. Esomeprazole magnesium [ESO] loaded pH sensitive NPs were prepared by nano-emulsification polymer crosslinking method and characterized. Sixteen formulations were prepared and the concentration of process variables was varied to obtain nanoparticles of 200-600nm. The NPs were found to be homogenous in size distribution. The encapsulation efficiency and drug loading ranged from 33.2% to 50.1% and 12.2% to 17.2% respectively. Particle size, encapsulation efficiency and drug loading increased along with co-polymer concentration. In-vitro release studies at pH 1.2 for 2 h, followed by pH 6.8 showed that environment pH significantly affected the drug release. SEM has shown that NPs are spherical with smooth surface. The pH sensitive PAAm-g-GGNPs resisted the initial release of the drug from the drug loaded NPs in acidic pH and delayed the release process to a longer period in alkaline environment