Synthesis and Safety Evaluation of a New Enteric Coating Material
A series of styrene-maleic anhydride (SMA)-ethanol polymers with different degree of esterification (DE) were synthesized, they had different pH-sensitive values and could be used as enteric coating materials. SMA-ethanol (DE50%) was used as the model compound to evaluate the safety as an enteric coating material, the results of acute toxicity tests showed that there was no acute toxicity. The reaction condition such as catalysts, catalyst amount, reaction time and temperature were also evaluated, the results indicated that the triethylamine (TEA) was the optimal catalyst, when methyl ethyl ketone (MEK) was the solvent, the catalyst amount was 15-20%(molar percent), the reaction at 80 OC for 8h could gain the highest conversation.
X. L. Lai et al., "Synthesis and Safety Evaluation of a New Enteric Coating Material", Advanced Materials Research, Vol. 266, pp. 157-160, 2011