Dirithromycin is a semi-synthetic macrolide antibiotic and pharmaceutical active ingredient. It is a prodrug that is rapidly converted in the body to erythromycylamine, the pharmacologically active compound. Dirithromycin has antibacterial activity against susceptible Gram-positive and selected Gram-negative microorganisms.
Dirithromycin is identified by CAS No. 62013-04-1. Its molecular formula is C42H78N2O14 and its molecular weight is approximately 835.08 g/mol.
Dirithromycin belongs to the macrolide antibiotic class and was developed as an orally administered prodrug of erythromycylamine. Following administration, it is hydrolyzed to the active compound, which inhibits bacterial protein synthesis.
Dirithromycin and its active metabolite exhibit antibacterial activity by interfering with bacterial protein synthesis. Activity is primarily associated with susceptible respiratory and other bacterial pathogens.
The active metabolite, erythromycylamine, binds to the 50S subunit of susceptible bacterial ribosomes. This inhibits bacterial protein synthesis and interferes with peptide-chain elongation.
The antibacterial effect is generally bacteriostatic, although activity may be bactericidal against certain susceptible organisms at appropriate concentrations.
Dirithromycin has been used in pharmaceutical formulations for susceptible bacterial infections, including:
Approved indications and regulatory status vary by country and product.
Dirithromycin is relevant to pharmaceutical manufacturers and formulation-development organizations working with macrolide antibiotics and oral antibacterial products.
It is primarily associated with oral pharmaceutical formulations and should be manufactured according to the applicable approved formulation and regulatory requirements.
Dirithromycin API quality evaluation may include:
Testing should be performed using validated analytical methods appropriate for the API and intended formulation.
Dirithromycin intended for pharmaceutical manufacturing should comply with applicable GMP, quality-control and regulatory requirements.
The final API specification should correspond to the intended market, applicable pharmacopoeial requirements and the manufacturer's approved product specification.
A batch-specific Certificate of Analysis (CoA) should provide relevant analytical results and acceptance criteria.
Dirithromycin 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.
Dirithromycin is relevant to pharmaceutical companies involved in macrolide antibiotic and antibacterial formulation development.
For commercial applications, customers should verify the API identity, grade, assay, purity, impurity profile, regulatory status, documentation and batch-specific CoA before use.
Consistent Dirithromycin API quality is important for reliable pharmaceutical formulation and manufacturing. Control of identity, potency, 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 1.0% |