Diltiazem Hydrochloride (Diltiazem HCl) is a pharmaceutical active ingredient belonging to the benzothiazepine class of calcium channel blockers. It is used in cardiovascular medicines for the management of conditions such as hypertension, angina pectoris and certain supraventricular tachyarrhythmias.
Diltiazem HCl works primarily by inhibiting the influx of calcium ions through L-type calcium channels in cardiac and vascular smooth muscle. This produces effects including reduced cardiac conduction, decreased heart rate and relaxation of vascular smooth muscle.
Diltiazem Hydrochloride is the hydrochloride salt of diltiazem and is widely used as an API in various oral and parenteral pharmaceutical formulations.
Diltiazem Hydrochloride is identified by CAS No. 33286-22-5. Its molecular formula is C22H27ClN2O4S and its molecular weight is approximately 450.98 g/mol.
Diltiazem is a calcium channel blocker that affects both cardiac and vascular smooth muscle. It decreases calcium-dependent contraction and slows conduction through the atrioventricular node.
Its pharmacological effects include:
Diltiazem inhibits the movement of calcium ions through L-type voltage-gated calcium channels in cardiac and vascular smooth muscle.
Reduced calcium influx decreases contractility and slows conduction through the AV node. In vascular smooth muscle, calcium-channel blockade produces vasodilation and reduces systemic vascular resistance.
Diltiazem HCl is used in pharmaceutical formulations for:
Approved indications and dosage forms may vary according to country and regulatory authority.
Diltiazem HCl is relevant to pharmaceutical manufacturers and formulation-development organizations working on cardiovascular and antihypertensive products.
It may be incorporated into immediate-release or modified-release oral formulations and other approved dosage forms according to the applicable product specification and regulatory requirements.
Diltiazem HCl API quality evaluation may include:
Testing should be performed using validated analytical methods appropriate for the API and intended formulation.
Diltiazem HCl intended for pharmaceutical manufacturing should comply with applicable GMP, quality-control and regulatory requirements.
The final specification should correspond to the intended market, applicable pharmacopoeial requirements and the manufacturer's approved product specification.
A batch-specific Certificate of Analysis (CoA) should provide relevant analytical results and acceptance criteria.
Diltiazem HCl should be stored in tightly closed, appropriately labelled containers under the manufacturer's recommended storage conditions. Protection from excessive moisture, heat and unsuitable environmental exposure should be maintained.
Diltiazem HCl is relevant to pharmaceutical companies developing and manufacturing antihypertensive, antianginal and cardiac-rate-control formulations.
For commercial pharmaceutical applications, customers should verify the API grade, identity, assay, purity, impurity profile, specification, regulatory documentation and batch-specific CoA before use.
Consistent Diltiazem HCl API quality is important for reliable formulation development and pharmaceutical manufacturing. Control of identity, assay, purity and related substances supports reproducible product quality.
Appropriate documentation may include a Certificate of Analysis, specification sheet, safety documentation and applicable regulatory information.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | NLT 98.0% by HPLC |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.5% |
| Heavy Metals | NMT 10 ppm |
| pH (1% Solution) | 2.0 – 4.0 |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 2.0% |
| Water Content | NMT 0.5% |
| Melting Point | 150°C – 154°C |