Cyclobenzaprine Hydrochloride (Cyclobenzaprine HCl) is a centrally acting skeletal muscle relaxant used for the short-term relief of acute, painful musculoskeletal conditions associated with muscle spasm. It is the hydrochloride salt form of cyclobenzaprine and is widely used as a pharmaceutical active ingredient in oral dosage forms.
Cyclobenzaprine HCl is a synthetic small-molecule pharmaceutical API belonging to the centrally acting skeletal muscle relaxant class. The hydrochloride salt provides a defined pharmaceutical form suitable for formulation and manufacturing applications.
Cyclobenzaprine Hydrochloride is identified by CAS No. 620-79-1. Its molecular formula is C20H22ClN, with a molecular weight of approximately 311.85 g/mol.
Cyclobenzaprine HCl acts primarily within the central nervous system to reduce excessive somatic motor activity. It helps relieve skeletal muscle spasm associated with acute painful musculoskeletal conditions.
Cyclobenzaprine HCl does not directly act on skeletal muscle fibers or the neuromuscular junction. Its muscle-relaxant activity is primarily centrally mediated.
Cyclobenzaprine HCl acts predominantly at the brainstem level and influences descending pathways involved in the regulation of somatic motor activity. This reduces tonic motor activity and contributes to the reduction of painful muscle spasm.
It also has anticholinergic and antihistaminic properties, which contribute to its overall pharmacological profile.
Cyclobenzaprine HCl is primarily used as an adjunct to rest and physical therapy for the relief of muscle spasm associated with acute, painful musculoskeletal conditions.
The API can be used in the development and manufacture of appropriate oral pharmaceutical dosage forms, subject to applicable regulatory requirements.
Cyclobenzaprine HCl may be incorporated into:
The dosage strength, excipients and release characteristics depend on the final approved pharmaceutical product.
Cyclobenzaprine HCl API quality evaluation may include:
Testing should be performed using validated analytical methods appropriate to the API and intended pharmaceutical application.
Cyclobenzaprine HCl intended for pharmaceutical manufacturing should comply with applicable GMP, quality-control and regulatory requirements. Specifications 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 contain applicable analytical results and acceptance criteria.
Cyclobenzaprine HCl should be stored in its original, appropriately closed packaging under the conditions specified by the manufacturer. Protection from excessive moisture, heat and unsuitable environmental exposure should be maintained to preserve API quality.
Cyclobenzaprine HCl is relevant to pharmaceutical manufacturers and formulation-development companies working on muscle-relaxant and musculoskeletal pharmaceutical products.
For commercial pharmaceutical applications, customers should verify the API's grade, assay, impurity profile, regulatory documentation, specification sheet and batch-specific CoA before use.
Consistent Cyclobenzaprine HCl quality is important for reliable pharmaceutical formulation and manufacturing. Appropriate control of identity, purity, assay, related substances and physical characteristics helps maintain consistency between production batches.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white crystalline powder |
| Identification | Conforms to Cyclobenzaprine HCl identity by validated analytical methods |
| Assay (HPLC) | NLT 98.0% by HPLC |
| Loss on Drying | NMT 1.0% |
| Heavy Metals | NMT 10 ppm |
| pH (1% Solution) | 2.0 – 4.0 |
| Individual Impurity | NMT 1.0% |
| Total Impurities | NMT 2.0% |
| Water Content | NMT 1.0% |
| Melting Point | 150°C – 154°C |