1. Basic Product Profile

• Full IUPAC Name: (3β,5β,7β)-3,7-dihydroxycholan-24-oic acid
• Aliases: UDCA, ursodiol, 3α,7β-dihydroxy-5β-cholan-24-oic acid
• CAS Number: 128-13-2
• EINECS: 204-880-3
• Molecular Formula: C24H40O4
• Molecular Weight: 392.57
• Chemical Classification: Natural bile acid steroid API, hepatoprotective pharmaceutical raw material, cholelithiasis treatment drug intermediate
• Core Advantages
  Hydroxylated steroid bile acid extracted from bear bile or synthetic route, two hydroxyl groups on steroid nucleus with unique β configuration. Reduces cholesterol saturation in bile, dissolves cholesterol gallstones, protects liver bile duct epithelial cells, inhibits liver fibrosis. Low systemic side effects, high oral bioavailability, stable crystal form for tablet/capsule formulation. Widely used in gallstone treatment, primary biliary cholangitis adjuvant therapy and liver protection preparations.

2. Physical & Chemical Properties

2.1 Physical Index

1. Appearance: White crystalline powder
2. Odor: Odorless
3. Solubility: Insoluble in water; slightly soluble in ethanol, methanol; soluble in acetone, chloroform, glacial acetic acid; insoluble in alkane oils
4. Melting Point: 203–208 °C
5. Specific Optical Rotation [α]D20: +57.0° ~ +60.0° (c=2, ethanol)
6. pH (saturated ethanol suspension): Weakly acidic
7. Hygroscopy: Non-hygroscopic under normal dry storage
8. UV characteristic: No obvious UV absorption peak

2.2 Chemical Properties

1. Structure feature: Four-ring steroid skeleton with 3β,7β dihydroxyl and terminal carboxylic acid group
2. Amphiphilic property: Carboxyl group forms soluble salts with alkaline substances (sodium ursodeoxycholate)
3. Hydroxyl reactivity: Two secondary hydroxyl groups can undergo esterification, acylation protection for chiral steroid synthesis
4. Thermal Stability: Stable below 190℃; decomposes above melting point to release fatty acid fragments
5. Acid & Alkali Stability: Stable in neutral/weak acid; soluble in dilute alkali solution; concentrated strong alkali heating triggers steroid side chain cleavage
6. Photostability: Slightly yellow after long-term strong UV irradiation; light-proof storage required
7. Compatibility: Compatible with common pharmaceutical excipients, polar organic solvents; incompatible with strong oxidants, concentrated mineral acids

3. Main Application Fields

3.1 Hepatobiliary Pharmaceutical API (Core Usage)

1. Oral tablets/capsules for cholesterol gallstone dissolution; avoids surgical cholecystectomy for eligible patients
2. First-line drug for primary biliary cholangitis (PBC), improves bile secretion and slows liver cirrhosis progression
3. Adjuvant hepatoprotective drug for drug-induced fatty liver and cholestatic liver injury

3.2 Chiral Steroid Synthetic Intermediate

3.3 Biochemical Research Reagent

3.4 Veterinary Pharmaceutical Raw Material

4. Quality Specification Table