L Cysteine Ethyl Ester Hydrochloride

L Cysteine Ethyl Ester Hydrochloride

Shaanxi Rebecca Biotechnology specializes in R&D and standardized production of high-purity fine biochemicals. We adopt low-temperature synthesis and gradient recrystallization technology to effectively reduce chiral impurities and oxidation by-products, ensuring high purity and stable chiral activity of finished products.

Our production is carried out in a nitrogen-protected environment, which perfectly shields the sensitive thiol groups of L Cysteine Ethyl Ester Hydrochloride and avoids activity degradation during processing. Supported by complete HPLC and ICP-MS testing systems, we strictly control heavy metals, residual solvents and related impurities in full compliance with ICH Q3C standards. Certified with ISO22000 and cGMP, we provide complete batch documents including COA, HPLC chromatograms and MSDS. We support custom particle size specifications and third-party testing, with stable global logistics and flexible cold-chain transportation to meet diverse overseas procurement and regulatory filing needs.

We select high-purity L-cysteine raw materials from certified and audited suppliers. The whole synthesis process is completed under inert nitrogen protection, including acid-catalyzed ethanol esterification and hydrochloric acid salt formation. Through multi-stage purification and precision recrystallization, we thoroughly remove D-isomers, unreacted raw materials and disulfide impurities to guarantee high chiral purity of the final product.

We offer two professional grades for different application scenarios: cosmetic grade for skin brightening and antioxidant topical formulas, and laboratory grade for cell culture, peptide synthesis and redox biochemistry research. Every batch is equipped with complete traceability records from raw material procurement, production processing to finished product QC release, supporting customer audits and global product registration.

This amino acid derivative dissolves freely in water and ethanol, forming clear and transparent solutions for direct formula preparation, while it is insoluble in non-polar solvents such as hexane and toluene. Product stability is strictly controlled for practical industrial and laboratory use: solid powder remains stable for long-term storage under sealed, low-temperature (2–8°C) and dry conditions. Moisture and air exposure will trigger oxidation and dimerization, affecting product activity.

Aqueous solutions oxidize rapidly, so fresh preparation before use is required; adding appropriate antioxidants can effectively extend the service life. To avoid ester hydrolysis and activity loss, keep the product away from high-temperature environments and maintain formula pH below 7. Long-term storage requires light-proof and air-tight sealing to prevent photo-oxidation.

We adopt standardized low-temperature synthesis and purification procedures to ensure consistent batch quality and complete chiral specificity:

High-purity raw materials are put into the reaction system under nitrogen protection, followed by precise low-temperature catalytic esterification to reduce side reactions.

Hydrochloric acid is added for salt formation and crude crystal precipitation. Vacuum filtration and water washing remove residual mother liquor and soluble impurities.

Gradient recrystallization and centrifugal separation further eliminate isomer impurities.

Low-temperature vacuum drying below 45°C protects ester bonds and thiol activity.

The finished powder is crushed, sieved and homogenized to achieve uniform mesh size and batch consistency.

Each batch undergoes full-index quality testing before being sealed and packaged with nitrogen.

Strict control of reaction temperature, pH value, drying time and oxygen isolation ensures stable quality of every batch of L Cysteine Ethyl Ester Hydrochloride.

We implement strict cGMP and ISO22000 quality management systems to control all production links. We detect chiral purity via optical rotation and HPLC to ensure D-isomer impurity content below 0.5%. Gradient HPLC is used to monitor disulfide dimers, free cysteine and other hydrolyzed impurities.

Residual solvents fully comply with ICH Q3C Class 3 safety standards. ICP-MS heavy metal detection and microbial testing strictly meet cosmetic and laboratory raw material grade requirements. Each batch is delivered with complete test documents, and third-party testing is supported to help customers complete overseas market access and regulatory filing efficiently.

We provide multi-specification sealed packaging to suit different procurement volumes: 1kg nitrogen-sealed aluminum foil bags, 5kg/10kg nitrogen-flushed aluminum cans for small and medium batches, and 25kg fiber drums with double inner plastic bags for bulk industrial orders. All packaging materials are moisture-proof and light-blocking, with clear batch information and storage instructions marked externally. We support neutral packaging, private labeling and customized mesh size specifications, and provide trial sample packages.

For global logistics, we use DHL/FedEx/UPS express for urgent samples and small orders, and sea freight for large-bulk shipments. Cold-chain transportation is available for high-standard quality protection. All shipments come with complete customs clearance documents and real-time logistics tracking to ensure safe and on-time delivery.

Q1: What are the core advantages compared with ordinary L-Cysteine HCl?

A1: Ethyl ester modification greatly improves lipophilicity and skin permeability. Compared with water-soluble ordinary cysteine hydrochloride, it delivers better transdermal absorption and antioxidant effects, more suitable for high-end cosmetic topical formulas.

Q2: How do you control product oxidation and impurities?

A2: The whole production process is completed under nitrogen protection, with nitrogen-filled sealing for finished products to suppress thiol oxidation. Each batch adopts HPLC detection to quantify dimer impurities, with detailed data listed in COA.

Q3: What are the standard storage and usage guidelines?

A3: Store sealed at 2–8°C, away from light, heat and air exposure. Aqueous solutions oxidize quickly, so prepare and use immediately. Adding antioxidants can effectively slow down oxidation.

Q4: Can you provide complete test data and chromatograms?

A4: Yes. Every batch is equipped with official COA, including HPLC chromatograms and optical rotation test data. Third-party authoritative testing is available on request.

Q5: What are the main application scenarios of this product?

A5: It is widely used for high-end skin brightening and antioxidant cosmetic formula research, cell culture redox experiments and chiral organic synthesis. It is not applicable for oral use without complete regulatory approval.

If you need product samples, technical datasheets, customized specifications or batch quotation support, feel free to contact our professional team at information@sxrebecca.com. We provide reliable biochemical raw material solutions and one-stop technical services for your projects with high-purityL Cysteine Ethyl Ester Hydrochloride.