This product is tetrahydropalmatine extracted from the aerial parts of Stephania tetrandra of the Menispermaceae family. Calculated on the dried basis, the content shall not be less than 98.0%.

【Characteristics】 This product appears as white or pale yellow flaky crystals. Odorless. Slightly bitter in taste. The color gradually deepens upon storage.

The melting point of this product (as per Appendix page 15, Part II of the Chinese Pharmacopoeia 1977 Edition) is 147^O to 149^O.

【Tests】 Loss on drying. Dry the product at 100g until constant weight is achieved. The loss in weight shall not exceed 1% (as per Appendix page 40, Part II of the Chinese Pharmacopoeia 1977 Edition). The residue on ignition shall not exceed 0.5% (as per Appendix page 42, Part II of the Chinese Pharmacopoeia 1977 Edition).

【Assay】 Weigh accurately about 0.5g of the product. Place it in a separatory funnel. Add 20ml of water. Shake and extract five times (25, 15, 10, 10, and 10ml). Combine the extracts. Rinse the filter with the washing solution. Combine the washings with the filtrate. Transfer to a container of predetermined weight. Evaporate on a water bath. Add 2ml of anhydrous ethanol to the residue. Evaporate to dryness. Dry at 105^O until constant weight is achieved. Weigh accurately to obtain the weight of C21H25O4N in the test sample.

【Storage】 Protect from light. Store in a sealed container.

Sichuan Jiexiang Medicinal Materials Raw Material Co., Ltd.