ABSTRACT A novel pH‐responsive polymeric drug delivery system is developed by covalently binding the active pharmaceutical ingredient paracetamol (PAR) to a synthesized vinyl propionate‐co‐maleic anhydride (VPR‐co‐MA) copolymer. The controlled release of PAR from the resulting VPR‐co‐MA‐PAR conjugate was investigated in vitro at various physiological pH values (2.0, 4.5, 7.4, and 9.0) at 37°C over a 6 h‐period. A fluorimetric method was utilized to quantify the released PAR, with optimal excitation and emission wavelengths determined to be 330 and 433 nm, respectively. The results demonstrated a distinct pH‐dependent release profile. After 6 h, the cumulative drug release was significantly suppressed at acidic gastric pH 2.0 (42.23%), whereas it was substantially higher at neutral and alkaline conditions, reaching 71.29% at pH 7.4 and a maximum of 74.46% at pH 9.0. The pronounced difference in release rates confirms the system's ability to limit premature drug release in the stomach while promoting targeted delivery in the intestinal tract. This VPR‐co‐MA‐PAR conjugate shows significant promise as a carrier for the controlled oral delivery of paracetamol.
Memis et al. (Wed,) studied this question.