Ritodrine is a synthetic beta-2 adrenergic receptor agonist and a phenethylamine derivative with tocolytic activity. The pharmaceutical API is commonly supplied as Ritodrine Hydrochloride, which acts on beta-2 receptors in uterine smooth muscle and reduces the intensity and frequency of uterine contractions.
Ritodrine Hydrochloride has been used in pharmaceutical formulations associated with the management of premature labor. Its pharmacological activity is related to stimulation of beta-2 adrenergic receptors, increasing intracellular cyclic AMP and reducing uterine smooth-muscle contraction.
Ritodrine Hydrochloride is the hydrochloride salt of ritodrine and is the appropriate pharmaceutical API form for this product page. It is identified by CAS No. 23239-51-2, molecular formula C17H22ClNO3, and molecular weight 323.8 g/mol.
Ritodrine Hydrochloride is also known by names including Ritodrine HCl, Ritodrine Hydrochloride, DU-21220 hydrochloride, and Yutopar. The API is a small-molecule pharmaceutical ingredient and is represented by a USP reference standard.
Ritodrine belongs to the phenethylamine class of sympathomimetic compounds. Its structure contains two phenolic hydroxyl groups, an amino group and a secondary alcohol, with the hydrochloride salt providing the pharmaceutical salt form.
The active moiety has defined stereochemistry, and the USP monograph specifically distinguishes ritodrine from its threo diastereomer during chromatographic impurity testing. This makes stereochemical and related-substance control important characteristics of Ritodrine Hydrochloride API.
Ritodrine Hydrochloride has five hydrogen-bond donors, four hydrogen-bond acceptors and six rotatable bonds according to PubChem. Its calculated molecular weight is 323.8 g/mol.
Ritodrine API is primarily associated with tocolytic pharmaceutical applications. Its beta-2 adrenergic activity reduces uterine smooth-muscle contractions and was the basis for its development for premature-labor management.
Pharmaceutical applications of Ritodrine Hydrochloride include:
Because regulatory availability and approved indications can vary by country and have changed over time, current market authorization should be confirmed for the intended jurisdiction before making regulatory claims.
Ritodrine Hydrochloride has a USP monograph with defined requirements for identity, assay, pH, loss on drying, residue on ignition, heavy metals and related compounds. USP specifies an assay range of 97.0–103.0%, calculated on the dried basis.
The USP identification includes IR spectroscopy and chromatographic retention-time comparison. The monograph also controls related compounds by liquid chromatography, including stereoisomeric and process-related impurities.
Important analytical controls include:
The USP monograph specifies NMT 1.0% loss on drying, NMT 0.2% residue on ignition, and NMT 0.002% heavy metals.
Ritodrine Hydrochloride is an established synthetic pharmaceutical API with a defined USP quality standard. Manufacturing requires appropriate control of chemical identity, assay, related compounds, moisture and inorganic residue.
A quality-focused Ritodrine API manufacturing program should provide:
The availability of a USP Ritodrine Hydrochloride Reference Standard further supports its established pharmacopoeial analytical framework.
Ritodrine Hydrochloride should be stored in tight, well-closed pharmaceutical containers under controlled environmental conditions.
The USP monograph specifies storage at 25°C, with permitted excursions between 15°C and 30°C.
Appropriate packaging should protect the API from contamination, excessive moisture and unsuitable environmental exposure throughout storage and transportation.
Ritodrine API documentation may include:
Ritodrine Hydrochloride is a well-characterized beta-2 adrenergic agonist with an established pharmacopoeial analytical framework. Its USP monograph provides defined requirements for assay, physical-quality attributes and related compounds, making controlled analytical testing an important part of pharmaceutical API quality.
A quality-focused Ritodrine API program should provide:
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 97.0–103.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.2% |
| pH (1% Solution) | 4.5–6.0 |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 2.0% |