Terazosin Hydrochloride API is the hydrochloride dihydrate form of terazosin, a quinazoline derivative and selective alpha-1 adrenergic receptor antagonist. It is used as an active pharmaceutical ingredient in medicines for the management of hypertension and symptoms associated with benign prostatic hyperplasia (BPH).
Terazosin Hydrochloride Dihydrate has the molecular formula C₁₉H₂₅N₅O₄·HCl·2H₂O and a molecular weight of 459.92 g/mol. The anhydrous hydrochloride form has CAS 63074-08-8, while the dihydrate pharmaceutical form is associated with CAS 70024-40-7.
USP identifies Terazosin Hydrochloride as a monohydrochloride dihydrate and specifies an assay range of 98.0–102.0% calculated with reference to the dried substance.
Terazosin is a quinazoline derivative containing a substituted quinazoline ring, piperazine moiety and tetrahydrofuran carbonyl group. The active molecule is a racemic compound. Terazosin Hydrochloride Dihydrate is the hydrochloride salt containing two molecules of water of crystallization.
Terazosin selectively antagonizes alpha-1 adrenergic receptors. Blocking these receptors reduces vascular smooth-muscle tone and produces vasodilation. In the prostate and bladder neck, alpha-1 receptor blockade decreases smooth-muscle tone and can improve urinary flow in patients with BPH.
Terazosin Hydrochloride API is used in pharmaceutical formulations intended for:
Terazosin is recognized as an alpha-1 adrenergic antagonist used for both hypertension and symptomatic BPH.
Terazosin produces its pharmacological effect primarily through selective antagonism of alpha-1 adrenergic receptors.
In vascular smooth muscle, alpha-1 blockade reduces vasoconstrictor activity and promotes vasodilation. In the prostate and bladder neck, blockade of alpha-1 receptors reduces smooth-muscle tone, supporting improved urinary flow in patients with benign prostatic hyperplasia.
Terazosin Hydrochloride is an established compendial drug substance. USP provides a specific monograph and reference standard for Terazosin Hydrochloride.
Typical quality-control testing includes:
The BP monograph for Terazosin Hydrochloride Dihydrate includes identification by IR and chloride reaction, pH testing and liquid-chromatographic control of related substances.
Swapnroop Drugs and Pharmaceuticals focuses on quality-oriented pharmaceutical API manufacturing for pharmaceutical development and manufacturing requirements.
For Terazosin Hydrochloride, important quality attributes include chemical identity, assay, crystalline form, water content, chromatographic purity and control of specified and unspecified impurities.
Terazosin Hydrochloride API should be packed in suitable pharmaceutical-grade, well-closed containers that protect the material from moisture, contamination and unsuitable environmental exposure.
USP specifies tight containers and storage at 20°C to 25°C for Terazosin Hydrochloride. Commercial storage should follow the applicable approved specification and validated stability data.
Depending on customer and regulatory requirements, documentation may include:
Swapnroop Drugs and Pharmaceuticals focuses on quality-oriented pharmaceutical API manufacturing and analytical control.
For Terazosin Hydrochloride, emphasis is placed on identity, assay, chromatographic purity, crystalline-form control, moisture-related attributes and appropriate impurity testing in accordance with the applicable pharmaceutical specification.
Swapnroop Drugs and Pharmaceuticals — quality-focused pharmaceutical API manufacturing from India.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 9.0% |
| Residue on Ignition | NMT 0.5% |
| Heavy Metals | NMT 10 ppm |
| pH (1% Solution) | 3.0 – 5.0 |