Tamoxifen 10540-29-1 — China API Manufacturer | USP/EP/BP R&D to Production

China Manufacturing Landscape for Tamoxifen

Tamoxifen (CAS 10540-29-1) is a selective estrogen receptor modulator (SERM) that remains a cornerstone therapy in the treatment and prevention of estrogen receptor-positive breast cancer. Listed on the WHO Model List of Essential Medicines, Tamoxifen is manufactured in substantial volumes to meet global demand across both branded and generic pharmaceutical markets. Chinese manufacturers, including our production facility, play a vital role in the global Tamoxifen supply chain, providing pharmaceutical-grade API (primarily as the citrate salt) to finished dosage manufacturers throughout Asia, Africa, the Middle East, Latin America, and increasingly to European and North American generic companies.

China’s established organic synthesis infrastructure and deep experience with triphenylethylene chemistry make the country a natural manufacturing base for Tamoxifen production. Our facility benefits from proximity to domestic suppliers of key intermediates including 4-hydroxybenzophenone, diethylaminoethanol derivatives, and McMurry coupling reagents, ensuring supply chain resilience and favorable production economics that translate into competitive pricing for our international customers.

Manufacturing Process & Facility

Tamoxifen synthesis at our facility employs an optimized multi-step route involving construction of the triphenylethylene backbone through a modified McMurry coupling or Grignard reaction approach, followed by O-alkylation with 2-(dimethylamino)ethyl chloride to introduce the critical aminoethoxy side chain. The Z/E geometric isomer ratio is controlled through reaction conditions and purification to ensure predominance of the pharmacologically active (Z)-isomer as required by pharmacopeial specifications. Salt formation with citric acid yields Tamoxifen citrate, the standard pharmaceutical form.

The production facility includes glass-lined reactors (500 L to 5,000 L), Hastelloy-lined vessels for corrosive reaction steps, rotary and vacuum dryers, and dedicated milling and sieving equipment. The facility operates under NMPA certification and has been inspected by multiple international regulatory authorities. Annual production capacity is 80 metric tons of Tamoxifen citrate API, with additional capacity available through validated contract manufacturing partnerships at satellite facilities.

Quality Standards & Multi-Pharmacopeial Compliance

Our Tamoxifen citrate API is manufactured to simultaneously comply with USP, EP, and BP pharmacopeial monograph specifications. HPLC purity exceeds 99.0%, with the (E)-isomer content controlled below 0.3% and individual specified impurities maintained below pharmacopeial limits. Assay by HPLC is reported on the dried basis, with results consistently within 98.5-101.0% of the theoretical value. Identity is confirmed by IR spectroscopy, UV-Vis absorption, and melting point determination.

Full analytical characterization includes related substances profiling by gradient HPLC, residual solvents by headspace GC per ICH Q3C, elemental impurities by ICP-MS per ICH Q3D, loss on drying, sulfated ash, and particle size distribution analysis. Genotoxic impurity assessment per ICH M7 is performed with validated sensitive analytical methods for identified potential mutagenic impurities. ICH Q1A stability studies support a 48-month retest period at room temperature controlled storage.

Regulatory Documentation

Complete regulatory support documentation is maintained and continuously updated. Our Tamoxifen citrate DMF is filed with the US FDA and referenced by multiple ANDA holders with approved products on the US market. EU ASMF documentation is available for European marketing authorization submissions. WHO Prequalification-compatible documentation packages are provided for customers serving tender markets in Sub-Saharan Africa, Southeast Asia, and other WHO procurement regions. Standard documentation with each order includes Certificate of Analysis, Certificate of Quality Compliance, TSE/BSE-free declaration, and ICH M7 genotoxic impurity assessment summary.

Packaging & Logistics

Tamoxifen citrate API is packaged in pharmaceutical-grade double PE bag-lined fiber drums in 10 kg and 25 kg configurations. The product is stable at room temperature and does not require cold chain handling, simplifying logistics and reducing shipping costs. Both sea freight and air freight options are available, with sea freight transit times of 20-35 days to major destination ports and air freight delivery within 5-10 business days. All export documentation including MSDS, commercial invoice, packing list, CoA, and customs classification assistance is provided as standard. Multiple Incoterms (FOB, CIF, DDP) are supported to accommodate customer logistics preferences.

Competitive Pricing & Supply Reliability

Tamoxifen citrate is produced at our facility in high volume, enabling competitive pricing that is consistently competitive in global benchmarking exercises. Annual supply agreements with fixed or indexed pricing provide customers with procurement cost stability. Standard lead times are 2-3 weeks from maintained stock for quantities up to 500 kg, and 4-6 weeks for larger campaign orders. As an essential medicine API, Tamoxifen citrate production is prioritized in our manufacturing schedule, with dedicated inventory maintained to ensure uninterrupted supply regardless of demand fluctuations or external disruptions.

Tamoxifen Citrate Specifications