Hydroxyzine Hydrochloride, commonly referred to as Hydroxyzine HCl, is an antihistamine with antipruritic, anxiolytic and sedative properties. It belongs to the first-generation antihistamine group and acts primarily by blocking histamine H1 receptors.
Hydroxyzine HCl is used in pharmaceutical formulations for the management of itching associated with allergic conditions, anxiety and as a sedative or premedication in appropriate clinical settings.
Hydroxyzine HCl is a synthetic pharmaceutical API requiring controlled manufacturing, purification and analytical testing. Quality control generally includes identity, assay, related substances, residual solvents, water content and control of elemental impurities.
The hydrochloride salt provides a suitable pharmaceutical form for incorporation into oral and other dosage formulations.
CAS Number: 2192-20-3
Molecular Formula: C21H28Cl2N2O2
Molecular Weight: 366.88 g/mol
Chemical Name: Hydroxyzine Hydrochloride
Drug Class: Antihistamine
Pharmacological Class: H1 Histamine Receptor Antagonist
Therapeutic Class: Antihistamine / Anxiolytic
Therapeutic Area: Allergy / Psychiatry / Dermatology
Hydroxyzine primarily acts as a histamine H1-receptor antagonist. By blocking H1 receptors, it reduces the effects of histamine responsible for symptoms such as itching and certain allergic manifestations.
It also produces activity within the central nervous system, contributing to its sedative and anxiolytic effects.
Hydroxyzine HCl is used in pharmaceutical formulations for:
The approved indications vary according to formulation, dosage and local regulatory labeling.
Hydroxyzine can help reduce itching and discomfort associated with allergic and dermatological conditions by antagonizing histamine H1 receptors.
Hydroxyzine has anxiolytic activity without being classified as a benzodiazepine. Its central nervous system effects can produce sedation, which is also relevant to its use as a premedication.
Hydroxyzine Hydrochloride is generally supplied as a white crystalline powder. It is soluble in water and has the physicochemical characteristics of an amine-containing hydrochloride salt.
Hydroxyzine HCl API quality evaluation may include:
Hydroxyzine HCl should be stored in a tightly closed container under controlled pharmaceutical conditions and protected from excessive heat, moisture and direct light. Storage conditions should follow validated stability data and the applicable product specification.
Hydroxyzine HCl remains relevant to pharmaceutical development involving H1-antihistamine pharmacology, histamine-mediated allergic responses, pruritus management, anxiolytic activity and sedative effects.
Hydroxyzine Hydrochloride is a first-generation H1-antihistamine with CAS Number 2192-20-3, molecular formula C21H28Cl2N2O2, and molecular weight 366.88 g/mol. It provides antihistaminic, antipruritic, anxiolytic and sedative effects and is used in approved formulations for selected allergic, dermatological and anxiety-related conditions.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Residue on Ignition | NMT 0.5% |
| Heavy Metals | NMT 20 ppm |
| pH (1% Solution) | 4.0 – 7.0 |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 2.0% |
| Water Content | NMT 2.0% |