Dimetindene is a first-generation antihistamine and pharmaceutical active ingredient belonging to the H1-receptor antagonist class. It is used primarily for the symptomatic relief of allergic skin conditions and other histamine-mediated symptoms.
Dimetindene is identified by CAS No. 5636-48-6. Its molecular formula is C20H24N2 and its molecular weight is approximately 292.42 g/mol.
Dimetindene is a synthetic antihistamine that blocks the effects of histamine at H1 receptors. It is used in pharmaceutical formulations intended to relieve itching and other symptoms associated with allergic reactions.
The active ingredient is also available in salt forms, including dimetindene maleate, which should be treated as a separate chemical entry when applicable.
Dimetindene competitively antagonizes histamine at H1 receptors. This reduces histamine-mediated effects such as itching, redness and increased vascular permeability.
As a first-generation antihistamine, Dimetindene may also have some central nervous system effects, depending on the dose and route of administration.
Dimetindene acts primarily as an H1 histamine receptor antagonist. By blocking histamine binding at H1 receptors, it reduces histamine-induced responses in peripheral tissues.
This contributes to relief of pruritus and other allergic symptoms.
Dimetindene is associated with pharmaceutical formulations used for symptomatic relief of:
Approved indications and dosage forms vary according to the country and specific pharmaceutical product.
Dimetindene is relevant to pharmaceutical manufacturers and formulation-development organizations working on antihistamine and dermatological products.
It may be incorporated into topical or systemic formulations according to the approved formulation, dosage form and applicable regulatory requirements.
Dimetindene API quality evaluation may include:
Testing should be performed using validated analytical methods appropriate for the API and intended formulation.
Dimetindene intended for pharmaceutical manufacturing should comply with applicable GMP, quality-control and regulatory requirements.
The final API specification should be established according to the intended market, applicable pharmacopoeial standards and the manufacturer's approved product specification.
A batch-specific Certificate of Analysis (CoA) should provide relevant analytical results and acceptance criteria.
Dimetindene API should be stored in tightly closed, appropriately labelled containers under the manufacturer's recommended storage conditions. Protection from excessive heat, moisture and unsuitable environmental exposure should be maintained.
Dimetindene is relevant to pharmaceutical companies developing and manufacturing antihistamine and dermatological formulations.
For commercial applications, customers should verify the API identity, chemical form, grade, assay, purity, impurity profile, regulatory documentation and batch-specific CoA before use.
Consistent Dimetindene 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 |