《美国药典》

(THE UNITED STATES PHARMACOPEIA,USP)

24版，25版收录辣椒碱资料原文

Capsaicin

    C18H27NO3 305.41

    6-Nonenamide, (E)-N-[(4-Hydroxy-3-methoxy-phenyl)methyl]-8-methyl.

    (E)-8-Methyl-N-vanillyl-6-nonenamide  [404-86-4].

    Capsaicin contains not less than 90.0 percent and not more than 110.0 percent of the labeled percentage of total capsaicinoids.The content of capsaicin (C18H27NO3) is not less than 55 percent, and the sum of the contents of capsaicin and dihydrocapsaicin (C18H29NO3) is not less than 75 percent, and the content of other capsaicinoids is not more than 15 percent, all calculated on the dried basis.

Caution——Handle Capsaicin with care. Prevent inhalation of particles of it and prevent its contact with any part of the body.

    Packaging and storage——Preserve in tight containers, protected from light, and store in a cool place.

    Labeling——Label it to state the percentage content of total capsaicinoids.

    USP Reference standards〈11〉——USP Capsaicin RS. USP Dihydrocapsaicin RS.

    Identification——Prepare a test solution of Capsaicin in methanol containing l mg per mL. Prepare a Standard solution of USP Capsaicin RS in methanol containing l mg per mL. Separately apply 10 -礚 portions of the test solution and the Standard solution to a thin-layer chromatographic plate(see Chromatography 〈21〉)coated with a 0.25-mm layer of chromatographic silica gel mixture. Develop the chromatograms in a solvent system consisting of a mixture of ether and methanol (19:1) until the solvent front has moved about threefourths of the length of the plate. Remove the plate from the chamber, and allow it to air-dry. Spray the plate with a 0.5% solution of 2,6-dibromoquinone-chlorimide in methanol, allow to stand in a chamber containing ammonia fumes, and examine the chromatograms:the blue color and the R value of the principal spot obtained from the test solution correspond to those properties of the principal spot obtained from the Standard solution.

    Melting range〈741〉: between 57°and 66°, but the range between beginning and end of melting does not exceed 5°.

    Loss on drying〈731〉: Dry it in vacuum over phosphorus pentoxide at 40°for 5 hours: it loses not more than 1.0% of its weight.

    Residue on ignition〈281〉: not more than 1.0%.

Content of capsaicin, dihydrocapsaicin, and other capsaicinoids—Mobile phase—Prepare a mixture of diluted phosphoric acid (l in 1000) and acetonitrile (600:400). Filter through a filter having a porosity of 0.5 祄 or finer, and degas. Make adjustments if necessary (see System Suitability under Chromatography〈621〉).

    Standard dihydrocapsaicin solution—Dissolve an accurately weighed quantity of USP Capsaicin RS quantitatively in methanol to obtain a solution having a known concentration of about 0.1 mg per mL.

Standard dihydrocapsaicin solution—Dissolve an accurately weighed quantity of USP Dihydrocapsaicin RS quantitatively in methanol to obtain a solution having a known concentration of about 0.025 mg per mL.

Test solution—Transfer about 25 mg of Capsaicin, accurately weighed, to a 250-mL volumetric flask, dilute with methanol to volume, and mix.

    Chromatographic system (see Chromatography〈621〉) —The liquid chromatograph is equipped with a 281-nm detector and a 4.6-mm x 25-cm column that contains 5-μm packing L11 and is maintained at a constant temperature of about 30°. Adjust the flow rate to obtain a retention time of about 20 minutes for the main capsaicin peak. Chromatograph the Standard capsaicin solution, and record the peak responses as directed for procedure: the relative standard deviation for replicate injections is not more than 2%.

    Procedure—Separately inject equal volunes (about 20 μL) of the Standard capsaicin solution, the Standard dihydrocapsaicin solution, and the Test solution into the chromatograph, record the chromatogram for a period of time that is twice that of the retention time of capsaicin, and measure the areas of the responses for all of the peaks. Calculate the percentage of capsaicin (C18H27NO3) in the portion of Capsaicin taken by the formula:

    25,000(C/W)(gu/gs),

    in which C is the concentration, in mg per mL, of USP Capsaicin RS in the Standard capsaicin solution, W is the weight, in mg, of Capsaicin taken to prepare the Test solution, and ru and rs are the capsaicin peak responses obtained from the Test solution, and the Standard ate the percentage of dihydrocapsaicin (C18H29NO3) in the portion of Capsaicin taken by the formula:

    25,000(C/W)(gu/gs),

    in which C is the concentration, in mg per mL, of USP Dihydrocapsaicin RS in the Standard capsaicin solution, W is the weight, in mg, of Capsaicin taken to prepare the Test solution, and ru and rs are the dihydrocapsaicin peak responses obtained from the Test solution and the Standard dihydrocapsaicin solution, respectively. The sum of the percentage of capsaicin found and of the percentage of dihydrocapsaicin found is not less than 75%. Using the chromatograms obtained from the Standard capsaicin solution and the Test solution, calculate the percentage of other capsaicinoids in the portion of Capsaicin taken by the formula:

    25,000(C/W)(gu/gs),

    in which C is the concentration, in mg per mL, of USP Capsaicin RS in the, W is the weight, in mg, of Capsaicin taken to prepare the Test solution, rT is the sum of the peak responses of the capsaicinoids other than capsaicin and dihydrocapsaicin in the chromatogram obtained from the Test solution, and rs is the capsaicin peak response obtained from the Standard capsaicin solution. Not more than 15% of other capsaicinoids is found.

译文

                        美国药典中记载的辣椒碱资料

    辣椒碱（辣椒素）

    分子结构式：C18H27NO3，分子量： 305.41，化学名：（反）－N－[（4－N－羟基－3－甲氧基苯基）－甲基]－8－甲基－6－壬烯基酰胺

    以干燥提取物计算，辣椒碱含辣椒二萜类化合物总量为标示量的90％－100%,其中辣椒素的含量达到50％以上，辣椒素和二氢辣椒素总量超过75％，其它辣椒素类化合物总量不足15％。

注意事项：小心处置辣椒碱，谨防吸入辣椒碱微粒，勿使身体接触辣椒碱。

    包装贮藏：密封包装，置避光，阴凉处保存。

    标示量：以辣椒二萜类化合物总百分含量表示。

    美国药典参考标准：美国药典辣椒素标准规范，美国药典二氢辣椒素标准规范。

    鉴别：配制1.0mg/ml辣椒碱甲醇溶液，配制符合美国药典标准的辣椒碱1.0mg/ml甲醇溶液作为对照液，分别点样于0.25mm厚硅胶、凝胶混合薄层板上，点样量为10礚，将薄层板放于乙醚－甲醇（19:1）展开剂中展开，待展开剂前沿至薄层板3/4处时将薄层板取出，晾干，用0.5% 2,6-二溴苯醌-氯化亚胺甲醇溶液喷雾显色，放于氨气中片刻，取出，鉴别色谱图：供试液主要斑点颜色（兰色）及R值与对照液主要斑点颜色（兰色）及R值一致。

    熔点〈741〉: 57°－66°, 一般熔融起始温度至结束温度温差不超过5°。

    干燥失重〈731〉: 置40°P2O5真空干燥器中干燥5小时，失重不超过1.0%。

    灼烧残渣：≤1.0％。

    辣椒素，二氢辣椒素及其它辣椒二萜类化合物含量测定：

    流动相：磷酸水溶液（l ：1000，V/V）：乙腈(600:400)混匀，0.5祄 微孔滤膜滤过，脱气。流动相视色谱行为可作适当调整。

    辣椒素对照液：精密称取美国药典标准的辣椒碱适量溶于甲醇中，配制约0.1 mg/mL的辣椒甲醇溶液。

    二氢辣椒素对照液：精密称取美国药典标准的辣椒碱适量溶于甲醇中，配制约0.025mg/mL的辣椒甲醇溶液。

    供试液：精密量取辣椒碱约25 mg于250 mL容量瓶中，甲醇稀释至刻度，摇匀。

色谱条件：检测波长281 nm，色谱柱（4.6 mm x 250 cm，5祄），柱温：30°，调流速使辣椒碱主要色谱峰保留时间约为20 min。 记录辣椒碱对照液色谱图及峰面积，重复进样，RSD≤2%。

样品处理：辣椒素对照液，二氢辣椒素对照液，供试液分别进样20 礚 ，记录色谱图至两倍主要色谱峰保留时间，记录所有色谱峰面积，按公式25,000(C/W)(ru/rs)计算辣椒素百分含量, 公式中C为辣椒素对照液浓度，单位mg/ mL,W为供试液中辣椒碱含量，单位mg，ru 和 rs分别代表供试液中和对照液中辣椒素峰面积。辣椒素含量不低于55％。按公式25,000(C/W)(ru/rs)计算二氢辣椒素含量，公式中 C 为二氢辣椒素对照液浓度，单位mg/mL, W 为供试液中辣椒素含量，单位为mg, ru 和 rs分别代表供试液和对照液中二氢辣椒素峰面积。测得辣椒素和二氢辣椒素总百分含量不低于75%. 根据记录供试液和对照液色谱图峰面积，按公式25,000(C/W)(ru/rs)计算其它辣椒二萜类化合物百分含量，公式中C为对照液中辣椒素浓度，单位mg/mL，W为供试液中辣椒素含量，单位为mg，ru为供试液中其它辣椒二萜类化合物而非辣椒素、二氢辣椒素峰面积之和，rs为对照液中辣椒素峰面积。其它辣椒二萜类化合物总百分含量不超过15％。