Development and characterization of pH-responsive polyethylene glycol-co-poly(methacrylic acid) polymeric network system for colon target delivery of oxaliplatin: Its acute oral toxicity study

An oral route of administration is a most acceptable route for a patient, so we designed chemically cross-linked polyethylene glycol-co-poly(methacrylic acid) oral hydrogels (PEGMA 4000) by free radical polymerization method for pH-responsive colon target delivery of oxaliplatin (OXP). Polyethylene glycol (PEG 4000) was cross-linked chemically with methacrylic acid (MAA) in distilled water. Ammonium peroxodisulfate (APS) and N, N-methylene bisacrylamide (MBA) were used as initiator and cross-linker respectively. OXP was loaded in prepared hydrogels. FTIR, DSC, TGA, SEM, and XRD were conducted for characterization of developed hydrogels which endorsed the formation of new polymeric network. The pH-sensitive behavior of hydrogels was observed by swelling dynamics and equilibrium swelling ratio at low (1.2) and higher pH (7.4). Toxicity study was also conducted on rabbits to evaluate toxicity and biocompatibility of developed carrier system to biological system. Hydrogels with higher PEG 4000 concentration showed maximum swelling and higher drug loading at 7.4 pH. Toxicity study confirmed the developed hydrogels as non-toxic and biocompatible for biological system. Resultantly, these hydrogels can become an excellent candidates for colon targeting of OXP to treat colorectal cancer with no toxicity.