Promazine is a phenothiazine derivative belonging to the first-generation antipsychotic class. The pharmaceutical API is commonly supplied as Promazine Hydrochloride, the hydrochloride salt of promazine. Promazine hydrochloride is identified in USP-NF and FDA substance records under CAS 53-60-1.
Promazine hydrochloride is chemically designated as 10-H-Phenothiazine-10-propanamine, N,N-dimethyl-, monohydrochloride. The compound has molecular formula C17H20N2S·HCl and molecular weight 320.88 g/mol.
Promazine Hydrochloride is a phenothiazine compound that exerts its pharmacological effects primarily through antagonism of dopamine receptors. It has historically been used as an antipsychotic and in other clinical applications associated with phenothiazine medicines.
For API identification, it is important to distinguish Promazine Hydrochloride (CAS 53-60-1) from other phenothiazines such as chlorpromazine and promethazine. FDA's substance registration identifies Promazine Hydrochloride separately under UNII U16EOR79U4.
| Parameter | Details |
|---|---|
| Product Name | Promazine |
| API Form | Promazine Hydrochloride |
| CAS Number | 53-60-1 |
| Molecular Formula | C17H20N2S·HCl |
| Molecular Weight | 320.88 g/mol |
| FDA UNII | U16EOR79U4 |
| Chemical Class | Phenothiazine |
| Therapeutic Class | First-generation antipsychotic |
| API Category | Active Pharmaceutical Ingredient |
| Appearance | Crystalline solid/powder |
| Pharmacopoeial Standard | USP-NF |
| Melting Range | 172–182°C |
| pH | 4.2–5.2 in 1 in 20 solution |
| Water/LOD | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 0.005% (50 ppm) |
| Solubility | Soluble in water; soluble in chloroform; methanol used for USP chromatographic testing |
The molecular identity and CAS number are confirmed by NIST, PubChem and FDA substance records.
Promazine is a phenothiazine antipsychotic API historically used in the treatment of psychotic disorders. Its pharmacological activity is associated with dopamine receptor antagonism.
Promazine hydrochloride has also been investigated and used historically in applications associated with behavioral and psychiatric disorders. Its pharmaceutical use depends on the regulatory status and approved indications of the relevant market.
Promazine Hydrochloride has a USP-NF monograph with defined requirements for assay, identification, pH, loss on drying, residue on ignition, heavy metals, selenium and chromatographic purity.
| Detailed Specification | Correct Value |
|---|---|
| Identification | Complies — IR / UV / Chloride |
| Assay (HPLC) | NLT 98.0% and NMT 102.0%, dried basis |
| LOD | NMT 0.5% at 105°C for 2 hours |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 0.005% (50 ppm) |
| pH (1% Solution) | 4.2–5.2 in 1 in 20 solution |
| Individual Impurity | NMT 1.0% |
| Total Impurities | NMT 2.0% |
| Water Content | N/A — USP specifies loss on drying separately |
| Specific Rotation | N/A — not a USP release requirement |
| Melting Point | 172–182°C |
| Solubility | Soluble in water; soluble in chloroform |
| Appearance | Crystalline solid/powder |
| Selenium | NMT 0.003% (30 ppm) |
The USP monograph specifies NLT 98.0% to NMT 102.0% after drying at 105°C for two hours. It also specifies pH 4.2–5.2, loss on drying NMT 0.5%, residue on ignition NMT 0.1%, and heavy metals at 0.005%.
For chromatographic purity, the USP procedure limits the sum of secondary spots to NMT 2.0%, with no single impurity exceeding 1.0%.
Important: USP's assay is actually performed by UV spectrophotometry at approximately 301 nm, not conventional HPLC. Therefore, if your CMS field specifically says "Assay (HPLC)," the scientifically accurate entry is 98.0–102.0% USP assay rather than claiming that the USP assay itself is an HPLC method.
Promazine Hydrochloride manufacturing requires controlled processing of the hydrochloride salt together with appropriate analytical verification of identity, assay, related substances, loss on drying and inorganic impurities.
The USP identification procedure includes infrared identification, an ultraviolet absorbance-ratio test and confirmation of chloride. The monograph also requires protection from light during analytical procedures because the material and solutions should be handled under subdued light or with low-actinic glassware.
Quality control can include IR, UV, HPLC/TLC chromatographic purity testing, assay, loss on drying, residue on ignition, heavy-metal testing and chloride identification.
USP specifies that Promazine Hydrochloride should be preserved in tight, light-resistant containers. Analytical procedures are also performed with protection from excessive light.
Recommended CMS storage wording:
Store in tight, light-resistant containers under controlled pharmaceutical storage conditions. Protect from excessive light, heat and moisture.
Typical documentation for Promazine Hydrochloride API may include:
Promazine Hydrochloride is a pharmacopoeial API with established USP quality requirements. Manufacturing and quality control should therefore focus on maintaining the correct hydrochloride identity, assay range, chromatographic purity, moisture control, inorganic residue and light-protected handling.
| 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% |
| Heavy Metals | NMT 50 ppm |
| pH (1% Solution) | 4.2–5.2 |
| Total Impurities | NMT 2.0% |
| Melting Point | 172–182°C |