Propiomazine is a phenothiazine derivative with predominantly sedative and hypnotic properties. The pharmaceutical substance is commonly represented as Propiomazine Hydrochloride, which has been used in medicinal preparations for sedation and sleep-related indications. PubChem and FDA substance records identify Propiomazine Hydrochloride as the hydrochloride salt of propiomazine.
The hydrochloride API has the chemical formula C₂₀H₂₅ClN₂OS and molecular weight 376.90 g/mol. Its CAS number is 1240-15-9 and FDA GSRS UNII is 70BO17YR03.
Propiomazine belongs to the phenothiazine chemical family and exhibits activity at several receptor systems, including histamine H1, dopamine, muscarinic, serotonin and alpha-adrenergic receptors. Its sedative effect is associated particularly with antihistaminic activity.
The free base is CAS 362-29-8, formula C₂₀H₂₄N₂OS, MW 340.482 g/mol. For the pharmaceutical hydrochloride API page, the preferred primary identity is CAS 1240-15-9, formula C₂₀H₂₅ClN₂OS, MW 376.90 g/mol.
| Parameter | Details |
|---|---|
| Product Name | Propiomazine |
| API Form | Propiomazine Hydrochloride |
| CAS Number | 1240-15-9 |
| Free Base CAS | 362-29-8 |
| Molecular Formula | C₂₀H₂₅ClN₂OS |
| Molecular Weight | 376.90 g/mol |
| Free Base Formula | C₂₀H₂₄N₂OS |
| Free Base Molecular Weight | 340.48 g/mol |
| FDA UNII | 70BO17YR03 |
| ChEMBL | CHEMBL1201068 |
| Chemical Class | Phenothiazine derivative |
| Therapeutic Classification | Sedative / hypnotic |
| API Category | Active Pharmaceutical Ingredient |
| Physical Form | Powder / crystalline solid |
| Appearance | Yellow, practically odorless powder |
| Water Solubility | Very soluble |
| Alcohol Solubility | Freely soluble |
| Benzene | Insoluble |
Historical chemical-reference information describes Propiomazine Hydrochloride as a yellow, practically odorless powder that is very soluble in water, freely soluble in alcohol and insoluble in benzene.
Propiomazine has historically been used primarily for its sedative and hypnotic effects, particularly in the management of insomnia and for sedation-related applications. PubChem lists its use as an insomnia/sedative agent and identifies the pharmaceutical substance as a discontinued human drug in the Drugs@FDA-linked data.
Historical pharmaceutical preparations included Propiomazine Hydrochloride as well as the maleate derivative. The hydrochloride was associated with the product Largon.
For API manufacturing and analytical purposes, the isolated hydrochloride is treated as a distinct substance and should not be confused with Propiomazine free base or Propiomazine Maleate.
Propiomazine Hydrochloride is identified in FDA/NLM substance records as Propiomazine Hydrochloride [USP], but I could not verify a publicly accessible current USP monograph containing the complete numerical API release table.
Therefore, I am not inventing USP assay, LOD, ROI, heavy-metal or impurity limits. Where reliable physical/reference values are available, they are provided separately.
A historical chemical reference gives the hydrochloride molecular weight as 376.94 g/mol and describes its physical characteristics, but that source does not establish a modern GMP API release specification.
Therefore, values such as 98–102% assay, 0.5% LOD, 0.1% ROI, 20 ppm heavy metals or specific impurity limits should not be presented as USP limits for Propiomazine Hydrochloride unless supported by the applicable current monograph or validated manufacturer specification.
Manufacturing of Propiomazine Hydrochloride requires appropriate control of the hydrochloride salt form and confirmation of chemical identity and chromatographic purity.
Analytical characterization may include HPLC, LC-MS, FTIR, NMR, residual-solvent testing, moisture determination and elemental impurity assessment. Because Propiomazine contains a phenothiazine structure and a basic dimethylamino side chain, analytical identity should clearly distinguish it from structurally related phenothiazines such as Promazine, Promethazine and Chlorpromazine.
The exact pharmaceutical substance should be identified using CAS 1240-15-9 rather than the free-base CAS 362-29-8.
Propiomazine Hydrochloride should be packaged in well-closed, light-protective pharmaceutical containers appropriate for the material's validated stability profile.
Recommended CMS wording:
Store in tightly closed containers under controlled pharmaceutical storage conditions. Protect from excessive light, heat, moisture and contamination.
Typical API documentation may include:
Propiomazine requires careful differentiation between its free base, hydrochloride and maleate forms. For pharmaceutical API applications, the hydrochloride form should be identified as CAS 1240-15-9, with the correct molecular formula and molecular weight.
| 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% |