Rheological characterization of an acetaminophen jelly

The aim of this study was to prepare an inclusion complex of acetaminophen and β-cyclodextrin (molar ratio of 1:1). A jelly with inclusion complexes formed by kneading was prepared. The formation of inclusion complexes was assessed by powder X-ray diffraction patterns and Fourier transform-infrared spectroscopy. Jellies were prepared with xanthan gum, gelatin, and κ-carrageenan. The concentration of each jelling agent was 0.5, 1.0, and 1.5% w/v. Viscoelasticity and dissolution characteristics were determined and osmometry was performed. PGWater(™), a commercial jelly for fluid replacement, served as a reference for viscoelastic characteristics and dissolution. Powder X-ray diffraction measurement revealed a different diffraction pattern for the kneading than for acetaminophen and β-cyclodextrin. Fourier transform-infrared spectroscopy revealed an absorption peak (at around 1655 cm(-1)) due to the carbonyl group and benzene ring (at around 1610 cm(-1)) of acetaminophen. In contrast, the kneaded mixture (1:1) had a shift in the absorption peak due to the carbonyl group (at around 1650 cm(-1)) in acetaminophen's molecular structure, and the formation of an inclusion complex was noted. The viscosity of xanthan gum-1.0, gelatin-1.5, and carrageenan-0.5 resembled the viscoelasticity of PGWater(™). The acetaminophen in gelatin-1.0 and carrageenan-0.5 had dissolution behavior similar to that of commercial acetaminophen preparations. The osmolality of jellies prepared in different concentrations ranged from about 20-50 mOsm/kg. Results suggested that carrageenan-0.5 could serve as a useful jelly vehicle for acetaminophen.