Effect of neutralization degree of methacrylic acid on hydrogel swelling and drug release

Abstract

Drug delivery system is an amazing tool which is widely used for drugprotection and its controlled release in order to enhance drug bioavailability,reduce side effects and therefore to improve overall therapy. Hydrogels havebeen attracted great attention as drug carriers due to their great physicochemicalproperties, similarity to the living tissues and biocompatibility. One group ofpH sensitive hydrogels are based on poly(methacrylic acid) (PMAA). Thesenon-toxic hydrogels are used as drug delivery system because they swell asa response to the change in pH of external environment and drug is beingreleased during the process. In present study, in order to improve the control ofdrug release rate, caffeine was encapsulated in liposomes which were furtherembedded into PMC hydrogel (PMCL). It was investigated how the change inneutralization degree of methacrylic acid affect the swelling degree of PMCLhydrogels and caffeine release in two environments at 37 °C for 24 h: 0.1 Mhydrochloride acid (pH 1) and phosphate buffer with pH value of 6.8 (pH 6.8), asa simulation of pH environment in human stomach and intestines, respectively.Obtained results show that PMCL hydrogels have great potential for controlledrelease of poorly water-soluble drugs in human intestines.