Tibolone API is a synthetic steroid hormone used primarily in hormone replacement therapy. It is structurally related to the 19-nortestosterone steroid family and exhibits estrogenic, progestogenic and androgenic activity through its parent compound and active metabolites. The British Pharmacopoeia describes tibolone as a steroid with estrogenic and progestogenic properties.
Tibolone has the molecular formula C₂₁H₂₈O₂, molecular weight 312.4 g/mol, and CAS number 5630-53-5. FDA GSRS identifies the substance with UNII FF9X0205V2.
The API is recognized in the European Pharmacopoeia, with the BP 2025 incorporating Ph. Eur. monograph 1739. The monograph specifies the chemical definition, assay, related substances, optical rotation, loss on drying and sulfated ash.
Tibolone is chemically defined as 17-hydroxy-7α-methyl-19-nor-17α-pregn-5(10)-en-20-yn-3-one. It is a crystalline steroid and exhibits polymorphism, meaning that different crystalline forms can occur.
After administration, tibolone is metabolized to active metabolites with different hormonal activities. Its pharmacological profile therefore differs from that of a conventional single-receptor estrogen.
Tibolone itself and its metabolites interact with steroid hormone receptors. Its metabolites have estrogenic, progestogenic and androgenic effects, producing a tissue-selective hormonal profile.
This pharmacological activity makes tibolone useful in postmenopausal hormone therapy, where it can provide relief of menopausal symptoms while also having effects on bone and other hormone-responsive tissues.
Tibolone is primarily used for the treatment of menopausal symptoms associated with estrogen deficiency and for prevention of postmenopausal bone loss in appropriate patients.
It has been used in hormone replacement therapy formulations in several countries. Regulatory status and approved indications vary by jurisdiction.
Tibolone is a synthetic steroid API manufactured through controlled chemical synthesis, purification, crystallization and drying. Because the substance exhibits polymorphism and contains several stereogenic centers, control of solid form, stereochemical identity and related substances is important.
A qualified Tibolone API Manufacturer in India should maintain validated chromatographic methods and controls covering assay, specified impurities, unspecified impurities, moisture and inorganic residue.
Tibolone is described as a white or almost white crystalline powder or crystals. It is practically insoluble in water and soluble in acetone and methanol. The BP monograph also notes that tibolone exhibits polymorphism.
A Canadian regulatory product monograph reports a melting point of approximately 165–170°C and specific optical rotation of +100° to +106° on the dried substance.
The BP/Ph. Eur. monograph specifies storage at 2°C to 8°C.
Bulk API should be packaged in suitable moisture- and light-protective containers according to the validated stability and packaging system.
A professional Tibolone API supply package may include:
A reliable Tibolone API Manufacturer in India should provide pharmaceutical-grade material with validated HPLC testing, controlled steroid-related impurities and comprehensive batch documentation. The established Ph. Eur./BP monograph provides defined numerical requirements for assay, impurities, loss on drying and sulfated ash.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |
| Water Content | NMT 0.5% |
| Specific Rotation | +100° to +106° |
| Melting Point | 165–170°C |