Testolactone API is a synthetic steroidal lactone and antineoplastic pharmaceutical ingredient. It is an aromatase inhibitor that has been used in the management of hormone-responsive breast cancer. Testolactone has the molecular formula C₁₉H₂₄O₃, CAS 968-93-4, and molecular weight 300.40 g/mol.
Testolactone is structurally related to the steroid nucleus but contains a six-membered lactone ring. It is also known by names including Teslac, 1-Dehydrotestolactone and Delta(1)-Testolactone.
PubChem identifies Testolactone as a seco-androstane and 3-oxo steroid derivative. FDA's historical Teslac labeling describes it as a synthetic antineoplastic agent.
Testolactone is a steroidal lactone characterized by a six-membered lactone ring in place of the conventional five-membered carbocyclic D-ring found in many steroid structures. PubChem reports five defined stereocenters and a molecular weight of 300.4 g/mol.
The API is described as a white to off-white crystalline powder or crystalline solid. Historical FDA labeling describes Testolactone as a white, odorless, crystalline solid, soluble in ethanol and slightly soluble in water.
Testolactone has been used as an antineoplastic hormonal agent in hormone-responsive breast cancer. Its pharmacological activity is associated with inhibition of steroid aromatase activity and reduction of estrogen synthesis.
Because Testolactone is an established pharmaceutical substance with historical clinical use, its API quality should be controlled using applicable pharmacopoeial and regulatory specifications.
Testolactone's principal pharmacological action is inhibition of steroid aromatase activity. This reduces conversion of adrenal androstenedione into estrone and thereby decreases estrogen biosynthesis, particularly relevant to postmenopausal estrogen-dependent disease. Historical FDA labeling describes the aromatase inhibition as potentially noncompetitive and irreversible based on in-vitro studies.
Testolactone has a USP drug-substance monograph. The USP monograph defines Testolactone as containing NLT 95.0% and NMT 105.0% of Testolactone, calculated on the dried basis.
Typical quality-control testing for Testolactone includes:
The applicable release specification should follow the current approved pharmacopoeial or customer specification.
Swapnroop Drugs and Pharmaceuticals focuses on quality-oriented pharmaceutical API manufacturing for pharmaceutical development and manufacturing requirements.
For Testolactone, important quality attributes include chemical identity, assay, chromatographic purity, moisture control, related substances and compliance with the applicable pharmaceutical specification.
Testolactone API should be packed in suitable pharmaceutical-grade, well-closed containers that protect the material from moisture, contamination and unsuitable environmental exposure.
Storage conditions should follow the applicable approved specification, validated stability data and packaging configuration.
Depending on customer and regulatory requirements, documentation may include:
Swapnroop Drugs and Pharmaceuticals focuses on quality-oriented pharmaceutical API manufacturing and analytical control.
For Testolactone, emphasis is placed on chemical identity, assay, chromatographic purity, moisture-related attributes and control of applicable impurities in accordance with the relevant pharmaceutical specification.
Swapnroop Drugs and Pharmaceuticals — quality-focused pharmaceutical API manufacturing from India.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 95.0% – 105.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.2% |
| Heavy Metals | NMT 20 ppm |
| Individual Impurity | NMT 1.0% |
| Total Impurities | NMT 3.0% |
| Water Content | NMT 0.5% |
| Melting Point | Approximately 218–220°C |