本章内容及讲授的改进意见 复习思考题

1. 阿司匹林原料药物与及阿司匹林肠溶片在质量检验方面有哪些不同之处？为何不同？ 2. 阿司匹林肠溶片释放度检查中为什么要更换溶剂？ 教具及教学设备要求

50ml烧杯，10ml离心管，电炉，水浴锅，滴管，滴定管。

Experiment 2 The Analysis of Aspirin and Aspirin

Enteric-coated Tablets

I. Purpose

1. To learn about the procedures and the items for drug analysis. 2. To experiment on the analysis of Aspirin and its Enteric-coated Tablets.

2. Contents and teach time assignment

Description Dissolubility--------------------------------(30min) Identification announcements--------------------------------(1hour)

(1) To about 0.1 g add 10 ml of water， boil and cool. Add 1 drop of ferric chloride TS； a violet colour is produced.

(2) To about 0.5 g add 10 ml of sodium carbonate TS， boil for 2 minutes and cool. Add dilute sulfuric acid in excess； a white precipitate is produced and an odour of acetic acid is perceptible. Examination ------------------------------------------(1hour) Clarity of solution Salicylic acid

Assay -------------------------------------(5.5hour) Material direct titration using sodium hydroxide Tablet

two-step titration.

References

the Volumn 2 of Chinese Pharmacopoeia

Focal point

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The preparation of neutro- alcohol How to operate tow-step titration

Discussion

1. What is the difference between the assay of aspirin and its enteric-coated tablets? 2. Give an explanation of the purpose of the solvent changing during the drug release test

of aspirin enteric-coated tablets.

teaching device

50ml beaker; 10ml centrifuge tube . electric furnace , thermostat-controlled waterbath, volume buret

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实验三 复方磺胺甲噁唑片的质量分析

教学目的

1. 熟悉复方制剂双波长计算分光光度方法含量测定原理； 2. 掌握复方磺胺甲噁唑片实验的操作条件及要点。 本章讲授提纲及学时分配

【性状】本品为白色片。标示量等特性――――（20min）

【鉴别】 (1)取本品的细粉适量（约相当于磺胺甲噁唑50mg），显芳香第一胺的鉴别反应（中国药典2000年版二部附录Ⅲ）。

(2)取本品的细粉适量（约相当于甲氧苄啶50mg），加稀硫酸10ml，微热溶解后，放冷，滤过，滤液加碘试液0.5ml，即生成棕褐色沉淀。――――――化学反应式（1.5hour）

【含量测定】 ―――――――――――（6hour）

磺胺甲噁唑 照分光光度法（中国药典2000年版二部附录Ⅳ A），以257nm为测定波长（λ2），在304nm为参比波长（λ1），要求ΔA＝Aλ2-Aλ1＝0。再在λ2与λ1波长处分别测定供试品溶液的稀释液与对照品溶液(1)的稀释液的吸收度，求出各自的吸收度差值（ΔA），计算，即得。

甲氧苄啶 照分光光度法（中国药典2000年版二部附录Ⅳ A），以239nm为测定波长（λ2），在295nm波长为参比波长（λ1），要求ΔA＝Aλ2－Aλ1＝0，再在λ2与λ1波长处分别测定供试品溶液的稀释液与对照品溶液(2)的稀释液的吸收度，求出各自的吸收度差值（ΔA），计算，即得。 本课程学科的新进展

另有方法测定为HPLC。 教学参考书

中国药典2000年版二部 本章内容的重点 双波长测定法的原理 本章内容的难点 双波长测定法的原理 复习思考题

1. 分别说明本品中磺胺甲噁唑和甲氧苄啶双波长法含量测定时波长选择的依据；

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2. 为何甲氧苄啶含量测定时供试液的稀释倍数与磺胺甲噁唑测定时的要不同？

教具及教学设备要求

50ml烧杯，10ml离心管，研钵，电子天平，100ml容量瓶，50ml容量瓶，紫外分光光度仪，比色皿。

Experiment 3 The Analysis of Compound Sulfamethoxazole

Tablets

I. Purpose

1. To study the spectro-photometric method for the simultaneous determination of drug

components in compound formulation.

2. To experiment on the assay of Compound Sulfamethoxazole Tablets by the

spectro-photometric method.

2. Contents and teach time assignment

Description White tablets --------------------------------(20min) Identification announcements--------------------------------(1.5hour)

(1) Yields the reactions characteristic of primary aromatic amines (Appendix III )， using a quantity of the powdered tablets equivalent to about 50 mg of Sulfamethoxazole.

(2) To a quantity of the powdered tablets equivalent to about 50 mg of trimethoprim add 10 ml of dilute sulfuric acid， heat gently to dissolve， cool and filter. To the filtrate add 0.5 ml of iodine TS， a dark brown precipitate is produced. Assay ----------------------------------------(6hour)

Sulfamethoxazole ?2=257 nm, ?1=304 nm, so that A?2?A?1=0. Measure the absorbance of diluted test solution and that of diluted reference solution (1) at wavelengths ?2 and ?1， calculate the difference in absorbance (?A ) for each solution and the content of C10H11N3O3S.

Trimethoprim ?2=239 nm, ?1=295 nm, so that A?2?A?1=0. Measure the absorbance of diluted test solution and that of diluted reference solution (2) at wavelengths ?2 and ?1， calculate the difference in absorbance (?A) for each solution and the content of C14H18N4O3.

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