Raloxifene Hydrochloride is the hydrochloride salt of raloxifene and belongs to the selective estrogen receptor modulator (SERM) class. It is an active pharmaceutical ingredient used primarily in the management and prevention of osteoporosis in postmenopausal women. It also exhibits estrogen-antagonistic activity in breast and uterine tissue.
Raloxifene Hydrochloride is identified by CAS 82640-04-8, molecular formula C₂₈H₂₇NO₄S·HCl and molecular weight 510.04 g/mol. FDA GSRS lists CAS 82640-04-8 as the primary identifier.
Raloxifene Hydrochloride is chemically a benzothiophene derivative containing phenolic hydroxyl groups and a piperidinoethoxy substituent. The hydrochloride salt is the pharmaceutical form used for raloxifene drug products.
The current USP monograph defines Raloxifene Hydrochloride as C₂₈H₂₇NO₄S·HCl, molecular weight 510.04, and specifies an assay of 97.5–102.0% on the dried basis.
| Parameter | Details |
|---|---|
| Product Name | Raloxifene Hydrochloride |
| CAS Number | 82640-04-8 |
| Molecular Formula | C₂₈H₂₇NO₄S·HCl |
| Molecular Weight | 510.04 g/mol |
| Free Base CAS | 84449-90-1 |
| Drug Class | Selective Estrogen Receptor Modulator |
| Therapeutic Class | Osteoporosis / Hormonal Therapy |
| FDA UNII | 4F86W47BR6 |
| PubChem CID | 54900 |
| Physical Form | Solid / crystalline material |
| Appearance | Light yellow to yellow/green powder to crystal |
FDA GSRS and USP-reference-standard information support the CAS, formula and molecular weight.
Raloxifene Hydrochloride is primarily used as a selective estrogen receptor modulator for:
Raloxifene acts as an estrogen agonist in bone while functioning as an estrogen antagonist in breast and uterine tissue.
Raloxifene Hydrochloride has a USP monograph with defined requirements for assay, related substances, loss on drying, residue on ignition and heavy metals.
The current USP 2025 assay specification is 97.5–102.0% on the dried basis. The USP related-substance procedure specifies raloxifene 3,7-diketone NMT 0.20%, any unspecified individual impurity NMT 0.10%, and total impurities NMT 0.50%.
The monograph also specifies loss on drying NMT 0.5%, residue on ignition NMT 0.1%, and heavy metals NMT 10 ppm.
Raloxifene Hydrochloride manufacturing requires controlled synthesis and purification to achieve consistent assay, impurity profile and hydrochloride salt quality.
Critical quality controls include:
The USP monograph specifies preservation in well-closed containers and storage at room temperature.
Commercial analytical references recommend a cool, dark storage environment below 15°C, but for a pharmaceutical API, the final storage condition should follow the validated stability program.
Typical Raloxifene HCl API documentation can include:
Raloxifene Hydrochloride benefits from a well-defined USP quality framework covering assay, related substances, loss on drying, residue on ignition and heavy metals. A pharmaceutical API manufacturing program should therefore align its analytical controls with the applicable USP requirements and maintain consistent batch-to-batch quality.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 97.5–102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.10% |
| Heavy Metals | NMT 10 ppm |
| pH (1% Solution) | 5–7 |
| Individual Impurity | NMT 0.10% |
| Total Impurities | NMT 0.50% |
| Water Content | NMT 1.0% |