Norethindrone Acetate is a synthetic progestin active pharmaceutical ingredient (API) and the acetate ester of norethindrone. It is a steroidal hormone derivative widely used in pharmaceutical formulations intended for hormone-responsive gynecological conditions and reproductive health applications. The compound is also known internationally as Norethisterone Acetate. Its established chemical identity is associated with CAS Number 51-98-9, molecular formula C22H28O3, and molecular weight 340.46 g/mol.
CID 5832 - PubChem+1
Norethindrone Acetate is an orally active synthetic progesterone analogue that produces progestational effects by interacting with progesterone receptors in target tissues. It is an important pharmaceutical molecule in steroid hormone formulation development and is included in recognized pharmacopoeial standards such as USP.
DailyMed+1
Norethindrone Acetate is a specialized steroidal hormone pharmaceutical API used in the development and manufacture of hormone-based pharmaceutical dosage forms.
Important pharmaceutical quality attributes include:
The USP monograph establishes an official assay requirement for Norethindrone Acetate, making pharmacopoeial values preferable to generic API assumptions.
USP
Product Name: Norethindrone Acetate
International Name: Norethisterone Acetate
Synonyms: Norethindrone 17-Acetate, 19-Norethindrone Acetate, Norethisterone 17-Acetate
CAS Number: 51-98-9
Molecular Formula: C22H28O3
Molecular Weight: 340.46 g/mol
Chemical Name: 17-Hydroxy-19-nor-17α-pregn-4-en-20-yn-3-one Acetate
IUPAC Name: [(8R,9S,10R,13S,14S,17R)-17-ethynyl-13-methyl-3-oxo-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-17-yl] acetate
Drug Class: Synthetic Progestin
Therapeutic Class: Progestational Hormone
Therapeutic Area: Gynecology and Reproductive Health
Molecule Type: Synthetic Steroidal Small Molecule
The molecular identity, nomenclature and chemical descriptors are supported by PubChem and the USP monograph.
CID 5832 - PubChem+1
Norethindrone Acetate acts as a synthetic progestin by binding to progesterone receptors in reproductive tissues and influencing progesterone-responsive gene expression.
Its pharmacological actions include:
After oral administration, Norethindrone Acetate is rapidly converted to norethindrone, which is responsible for much of its systemic pharmacological activity.
DailyMed+1
Norethindrone Acetate API is relevant to pharmaceutical formulations involving:
The approved therapeutic use of finished dosage forms depends on regulatory authorization in each market.
NORETHINDRONE ACETATE tablet+1
Finished pharmaceutical products containing Norethindrone Acetate have approved uses including:
These indications relate to approved finished drug products and should not be interpreted as claims regarding the API alone.
NORETHINDRONE ACETATE tablet+1
Norethindrone Acetate is described in official drug labeling as a white or creamy white crystalline powder.
Its physical characteristics include:
These characteristics are consistent with USP-labelled pharmaceutical material and recognized chemical references.
NORETHINDRONE ACETATE tablet+1
Norethindrone Acetate is practically insoluble in water and exhibits greater solubility in several organic solvents.
Reference chemical data describe:
Because solubility depends on solvent composition and analytical conditions, pharmacopoeial terminology is preferable for an API CMS page.
NCBI Bookshelf+1
A controlled Norethindrone Acetate API manufacturing process may involve:
The commercial manufacturing route should always follow validated process documentation and applicable GMP requirements.
Typical pharmaceutical quality-control testing may include:
FDA chemistry documentation confirms that assay, specific rotation, loss on drying, chromatographic purity and residual solvent testing are included within commercial API quality-control programs.
FDA Access Data
The USP monograph specifies the official assay requirement for Norethindrone Acetate as:
Not less than 97.0% and not more than 103.0%, calculated on the dried basis.
This verified USP numerical range is appropriate for publication when representing the API according to the USP standard.
USP
Specific rotation is an important stereochemical identity parameter for this steroid API because the molecule contains multiple defined stereocenters.
Reference pharmacopoeial data report:
Specific Rotation [α]D25: −32° to −38°
This value is useful for identity characterization where the applicable specification follows the corresponding pharmacopoeial method.
NCBI Bookshelf
Related substances are controlled using validated chromatographic procedures to monitor process-related impurities and degradation products.
For an official API CMS page:
Loss on drying is included within commercial API specifications, but publicly available FDA chemistry documentation redacts the proprietary numerical acceptance limit.
Therefore, the correct CMS approach is:
Loss on Drying: According to approved validated specification.
Residual solvents should comply with applicable ICH Q3C requirements and the validated API specification.
FDA Access Data
Norethindrone Acetate is a stereochemically defined steroid molecule containing multiple chiral centers.
Important stereochemical characteristics include:
Because the marketed API is a single defined stereochemical entity, stereochemical integrity is an important quality attribute.
CID 5832 - PubChem+1
Norethindrone Acetate should be stored in a tightly closed, light-resistant container under controlled pharmaceutical storage conditions.
Finished USP-labelled products recommend protection from light and controlled room-temperature storage. API storage should follow validated stability data and approved packaging specifications.
NORETHINDRONE ACETATE tablet+1
| Parameter | Specification |
|---|---|
| Appearance | White crystalline powder or crystals |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 97.0% – 103.0% |
| Specific Rotation | −32° to −38° ([α]D25) |
| Melting Point | 161–162°C |