Propacetamol hydrochloride (PRO) is a water-soluble prodrug of paracetamol (PA) which can be parenterally administered as analgesic for the treatment of postoperative pain, acute trauma, and gastric and/or intestinal disorders where oral administration is not possible. In these circumstances, PRO can be administered in physiologic or glucose solutions since it is rapidly and quantitatively hydrolyzed into PA by plasma estearases. We have studied the degradation kinetics of PRO in 5% glucose and 0.9% saline solutions at 4 °C and 25 °C (storage and room temperatures, respectively). The analytic technique used to determine PRO and PA quantitatively was first-derivative spectrophotometry. The degradation process of PRO can be best fitted to a second-order kinetics with independence of the medium used (saline or glucose solution). The hydrolysis kinetics of PRO conversion into PA depends on the temperature but not on the assay medium (saline or glucose solution). The degradation rate constants obtained for PRO were approximately 4.5 times higher at 25 °C than at 4 °C. The values of t90% for PRO were 3.17 h and 3.61 h at 25 °C, and 13.42 h and 12.36 h at 4 °C when the tests were performed in 5% glucose and 0.9% saline solutions, respectively.
盐酸丙帕他莫(PRO)是
对乙酰氨基酚(PA)的一种
水溶性原药,可作为镇痛剂经肠外给药,用于治疗无法口服的术后疼痛、急性创伤以及胃和/或肠道疾病。在这些情况下,PRO 可在生理溶液或
葡萄糖溶液中给药,因为它能被血浆雌
酯酶快速定量
水解为 PA。我们研究了 PRO 在 5%
葡萄糖溶液和 0.9% 生理盐
水溶液中于 4 °C 和 25 °C (分别为储存温度和室温)的降解动力学。用于定量测定 PRO 和 PA 的分析技术是第一衍生分光光度法。PRO 的降解过程最符合二阶动力学,与所用介质(生理盐
水或
葡萄糖溶液)无关。PRO 转化为 PA 的
水解动力学取决于温度,但与检测介质(生理盐
水或
葡萄糖溶液)无关。PRO 的降解速率常数在 25 °C 时比 4 °C 时高约 4.5 倍。在 5%的
葡萄糖溶液和 0.9%的生理盐
水溶液中进行试验时,PRO 的 t90% 值在 25 °C 时分别为 3.17 小时和 3.61 小时,在 4 °C 时分别为 13.42 小时和 12.36 小时。