Xylometazoline Hydrochloride is an imidazoline-derived sympathomimetic active pharmaceutical ingredient (API) belonging to the class of alpha-adrenergic receptor agonists. It is primarily used as a nasal decongestant in pharmaceutical formulations intended for the temporary relief of nasal congestion associated with the common cold, hay fever and respiratory allergies. Xylometazoline produces local vasoconstriction of nasal blood vessels, helping reduce swelling of the nasal mucosa and improving nasal airflow.
Xylometazoline Hydrochloride is the hydrochloride salt of xylometazoline. The compound is chemically identified as 2-[(4-tert-butyl-2,6-dimethylphenyl)methyl]-4,5-dihydro-1H-imidazole hydrochloride. PubChem lists CAS Number 1218-35-5, molecular formula C16H25ClN2, and molecular weight 280.83 g/mol. The BP/Ph. Eur. monograph gives the molecular representation as C16H24N2,HCl with a relative molecular mass of approximately 280.8.
Xylometazoline Hydrochloride is described in the BP/Ph. Eur. monograph as a white or almost white crystalline powder. It is freely soluble in water, ethanol (96%) and methanol. These properties make the hydrochloride salt suitable for incorporation into aqueous nasal pharmaceutical preparations.
The API has a defined pharmacopoeial quality profile. The Ph. Eur./BP monograph specifies a content of 99.0% to 101.0% on the dried substance. The monograph also specifies limits for related substances, loss on drying and sulfated ash, providing important quality-control parameters for pharmaceutical-grade material.
Xylometazoline belongs to the alpha-adrenoceptor agonist class. It acts locally on alpha-adrenergic receptors in the nasal mucosa. Activation of these receptors causes vasoconstriction of dilated nasal blood vessels, thereby reducing mucosal congestion.
Its principal pharmaceutical application is as a topical nasal decongestant. Xylometazoline is commonly formulated as nasal drops or nasal sprays at controlled concentrations. PubChem identifies xylometazoline as a nasal decongestant and alpha-adrenergic sympathomimetic.
Xylometazoline Hydrochloride API is used in the development and manufacture of pharmaceutical nasal preparations. Finished dosage forms may include nasal sprays, nasal drops and other locally administered nasal formulations.
The API is particularly relevant to products designed for temporary relief of nasal congestion associated with:
The WHO Model List information available through PubChem identifies xylometazoline nasal spray at 0.05% w/v, equivalent to 0.5 mg/mL, as a formulation for nasal congestion. This is a finished-product formulation concentration and should not be interpreted as an API assay specification.
Pharmaceutical-grade Xylometazoline Hydrochloride requires controlled chemical synthesis, purification and analytical testing to ensure identity, assay, purity and control of process-related impurities.
Pharmacopoeial testing includes infrared identification, chromatographic identification where applicable, appearance of solution, acidity or alkalinity, related substances, loss on drying, sulfated ash and assay. The BP/Ph. Eur. monograph specifically identifies xylometazoline impurity A as a specified impurity and also describes other detectable impurities.
For related substances, the monograph specifies:
The same monograph specifies loss on drying NMT 0.5%, determined at 105°C, and sulfated ash NMT 0.1%.
The BP/Ph. Eur. monograph specifies Xylometazoline Hydrochloride content of 99.0% to 101.0% on the dried substance. The assay is performed by potentiometric titration using 0.1 M perchloric acid. The monograph states that 1 mL of 0.1 M perchloric acid is equivalent to 28.08 mg of C16H25ClN2.
This pharmacopoeial range provides a useful verified numerical reference for pharmaceutical-grade Xylometazoline Hydrochloride API. Individual manufacturer specifications may include additional controls depending on the intended market, manufacturing process and applicable regulatory requirements.
Impurity control is an important part of Xylometazoline Hydrochloride API quality evaluation. The BP/Ph. Eur. monograph uses liquid chromatography for related-substance testing and identifies impurity A as a specified impurity.
The monograph also identifies several other potentially detectable impurities, including chloromethyl, nitrile, hydrocarbon and carboxylic-acid related compounds. Their control is addressed through the pharmacopoeial impurity framework.
Chromatographic testing is therefore important for confirming that the API meets the required pharmaceutical purity profile before use in finished dosage-form manufacturing.
Identity testing for Xylometazoline Hydrochloride can be performed using pharmacopoeial techniques including infrared absorption spectrophotometry. The BP/Ph. Eur. monograph also describes chromatographic and chemical identification procedures, including chloride identification.
For routine pharmaceutical quality control, analytical characterization may include:
The exact analytical procedure should follow the applicable pharmacopoeial monograph or approved specification for the intended market.
Xylometazoline Hydrochloride is an established API for nasal decongestant formulations. Its combination of aqueous solubility, pharmacological activity and established pharmacopoeial quality requirements makes it suitable for pharmaceutical development and manufacturing applications.
For API procurement and formulation development, important quality parameters include assay, impurity profile, moisture, inorganic residue, identification and physical characteristics. Pharmaceutical manufacturers can use these parameters when evaluating raw-material quality and establishing incoming-material controls.
The BP/Ph. Eur. monograph specifies that Xylometazoline Hydrochloride should be protected from light. Appropriate storage conditions should follow the applicable certificate of analysis, pharmacopoeial requirements and validated manufacturer recommendations.
Xylometazoline Hydrochloride API is an important pharmaceutical ingredient for the development and manufacture of nasal decongestant products. Its established pharmacopoeial standards provide defined quality requirements for assay, impurities, moisture and inorganic residue.
For pharmaceutical companies, formulation manufacturers and API procurement teams, pharmaceutical-grade Xylometazoline Hydrochloride can be evaluated based on pharmacopoeial compliance, analytical documentation, batch consistency and applicable regulatory requirements.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 99.0% – 101.0% on dried substance |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Individual Impurity | NMT 0.10% |
| Total Impurities | NMT 0.5% |
| Water Content | NMT 0.5% |