Propafenone Hydrochloride is the hydrochloride salt of propafenone and is a Class IC antiarrhythmic active pharmaceutical ingredient. It acts primarily by blocking fast sodium channels in cardiac tissue, reducing the rate of depolarization and slowing cardiac conduction. FDA labeling identifies propafenone hydrochloride as a white crystalline pharmaceutical substance with molecular weight approximately 377.92 g/mol.
The API is used in pharmaceutical formulations for the management of certain cardiac rhythm disorders, including paroxysmal atrial fibrillation and other clinically indicated supraventricular arrhythmias.
Propafenone Hydrochloride has the chemical name 2′-[2-Hydroxy-3-(propylamino)-propoxy]-3-phenylpropiophenone hydrochloride. The official USP and Japanese Pharmacopoeia records identify the substance as C₂₁H₂₇NO₃·HCl, molecular weight 377.90 g/mol, CAS 34183-22-7.
The substance occurs as a white or colorless crystalline powder/crystals. It is soluble in methanol and hot water and has limited solubility in water, ethanol and chloroform.
| Parameter | Details |
|---|---|
| Product Name | Propafenone Hydrochloride |
| API Form | Hydrochloride salt |
| CAS Number | 34183-22-7 |
| Molecular Formula | C₂₁H₂₇NO₃·HCl |
| Molecular Weight | 377.90 g/mol |
| Pharmacological Class | Class IC antiarrhythmic |
| Therapeutic Class | Antiarrhythmic API |
| Chemical Class | Propafenone derivative |
| Appearance | White/colorless crystalline powder or crystals |
| USP Status | USP-NF monograph |
| JP Status | Japanese Pharmacopoeia monograph |
| Melting Range | 171–175°C |
| pH | 5.0–6.2 in 1 in 200 solution |
| Water / LOD | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 20 ppm |
The physical and numerical quality parameters above are documented in the USP monograph information; the current USP revision subsequently removed melting range and clarity as release tests, so the melting range should be treated as a reference physical property, not a current USP release criterion.
Propafenone Hydrochloride is used as a Class IC antiarrhythmic. It reduces the fast inward sodium current in cardiac tissue and consequently slows cardiac conduction.
It is used in pharmaceutical products for appropriately selected patients with cardiac rhythm disorders, including paroxysmal atrial fibrillation and other supraventricular arrhythmias.
Propafenone Hydrochloride is supported by recognized pharmacopoeial specifications. The current USP-NF definition requires 98.0–102.0%, calculated on the dried basis.
The Japanese Pharmacopoeia database specifies a tighter 98.5–101.0% range on the dried basis.
Current USP revision information also indicates that the assay has been revised from titration to an HPLC procedure, with a typical propafenone retention time of approximately five minutes.
| Detailed Specification | Correct Value |
|---|---|
| Identification | Complies — IR / chromatographic identity |
| Assay (HPLC) | 98.0–102.0%, calculated on dried basis — USP |
| JP Assay | 98.5–101.0%, calculated on dried basis |
| LOD | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 20 ppm |
| pH (1% Solution) | 5.0–6.2 in 1 in 200 solution |
| Individual Impurity | N/A for a universal current numerical value — current USP detailed impurity limits require the applicable monograph version |
| Total Impurities | N/A for a universal current numerical value — current USP monograph preview does not expose the complete acceptance table |
| Water Content | N/A — loss on drying is the pharmacopoeial moisture-related test |
| Specific Rotation | N/A |
| Melting Point | 171–175°C — reference physical property; not a current USP release test |
| Solubility | Soluble in methanol and hot water; slightly soluble in alcohol/chloroform; practically insoluble in diethyl ether and toluene |
| Appearance | White/colorless crystalline powder or crystals |
The LOD 0.5%, ROI 0.1%, heavy metals 20 ppm and pH 5.0–6.2 values are documented in the USP monograph information.
Important: I am not inserting invented impurity limits into the CMS fields. The current USP revision confirms that the organic-impurities procedure has been revised, but the complete current acceptance table is not exposed in the public USP preview.
Manufacturing of Propafenone Hydrochloride requires control of the hydrochloride salt form, chemical identity, assay, chromatographic purity, moisture, inorganic residue and elemental impurities.
Analytical characterization may include HPLC, IR, UV-visible spectroscopy, chloride identification, loss-on-drying, residue-on-ignition and heavy-metal/elemental impurity testing. Current USP information confirms that the assay is based on an HPLC procedure in the revised monograph.
Propafenone Hydrochloride should be stored in well-closed containers under controlled pharmaceutical storage conditions. The older USP monograph specifies well-closed containers, while current pharmaceutical labeling describes the API as a crystalline solid.
Recommended CMS wording:
Store in tightly closed/well-closed containers under controlled pharmaceutical storage conditions. Protect from excessive heat, moisture and contamination.
Typical documentation can include:
Propafenone Hydrochloride has established USP-NF and Japanese Pharmacopoeia specifications, making pharmacopoeial compliance and analytical consistency important for pharmaceutical API manufacturing. Quality control should particularly address assay on a dried basis, chromatographic purity, moisture, residue on ignition and elemental impurities.
| 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 20 ppm |
| pH (1% Solution) | 5.0–6.2 |
| Melting Point | 171–175°C reference value |