关于对《中国药典》2020年版盐酸普鲁卡因水解鉴别试验的修订建议

Revision suggestions on the hydrolysis identification test of procaine hydrochloride in the Chinese Pharmacopoeia 2020

目的:针对《中国药典》2020年版盐酸普鲁卡因水解鉴别试验中水解温度、时间及盐酸浓度、用量等未提供参考数据,影响实验快速准确进行和实验现象出现,提出改进方法,为《中国药典》2020年版盐酸普鲁卡因水解鉴别试验的修订提出建议。方法:分别考察水解温度及盐酸(36%)加入量、盐酸浓度(36.0%、10.0%、5.0%、2.5%、0.625%)及用量对实验现象的影响,明确水解温度及时间、盐酸浓度及用量参考值。结果:不同温度下水浴加热,随着水浴温度的升高,热至油状物消失的时间逐渐缩短;以36%盐酸酸化,至出现白色絮状沉淀,消耗盐酸的量为0.1~0.2 mL,即2~4滴;继续加盐酸0.05 mL即1滴后白色絮状沉淀消失,溶液澄清。采用电热套加热(平均加热温度为275℃),各组加热至油状物消失的时间较为接近,约为10 min。随着盐酸浓度的降低,滴加盐酸至白色沉淀现象出现所消耗盐酸的量逐渐增加,继续滴加盐酸至溶液澄清消耗盐酸的量也逐渐增加。但即使盐酸浓度稀释至0.625%,滴加盐酸也会出现白色絮状沉淀现象。结论:从操作便捷省心省力、既保证加热水解完全又避免溶液蒸干,可考虑用水浴。综合考虑白色絮状沉淀(对氨基苯甲酸)的生成,同时避免滴加盐酸过量致使沉淀消失,可以10%盐酸进行酸化。

Objective:In view of the fact that reference data was unavailable for hydrolysis temperature and time,hydrochloric acid concentration and quantity in the hydrolysis identification test of procaine hydrochloride in the Chinese Pharmacopoeia 2020,which affected the rapid and accurate conduct of the experiment and the appearance of experimental phenomena,an improved method was proposed to the revision of the hydrolysis identification test of procaine hydrochloride in the Chinese Pharmacopoeia 2020.Methods:The effects of hydrolysis temperature and the quantity of hydrochloric acid(36%),the concentration of hydrochloric acid(36.0%,10.0%,5.0%,2.5%,0.625%)and its quantity of each concentration on experimental phenomena were investigated to obtain the reference values of hydrolysis temperature and time,hydrochloric acid concentration and quantity.Results:When a water bath was heated to different temperatures,the time from heating to the disappearance of oil was gradually shortened with the increase of water bath temperature;acidification with 36%hydrochloric acid until white flocculent precipitation occurred,the consumed quantity of hydrochloric acid was 0.1-0.2 mL,i.e.,2-4 drops;after 0.05 mL(1 drop)of hydrochloric acid continued to be added,the white flocculent precipitate disappeared and the solutionbecame clear.When heating with electric heating jacket(the average heating temperature was 275℃),the time for each group to heat until disappearance of the oil s was relatively close,about 10 min.With the decrease of hydrochloric acid concentration,the consumed quantity of hydrochloric acid gradually increased until white precipitate appeared,and the consumed quantity of hydrochloric acid also gradually increased until the solution recovered clear.However,even if the concentration of hydrochloric acid was diluted to 0.625%,the white flocculent precipitation appeared after hydrochloric acid was dropped.Conclusion:The water bath can be considered from the viewpoint of convenient operation,saving effort,ensuring complete heating hydrolysis and avoiding evaporation of the solution.Considering the generation of white flocculent precipitate(4-aminobenzoic acid)and avoiding the disappearance of the precipitate by adding too much hydrochloric acid dropwise,10%hydrochloric acid can be used for the acidification.