Beijing Dilun Biotechnology Develops Comprehensive Process for High-Purity Peptide Production

Beijing Dilun Biotechnology Co., Ltd., a subsidiary of Peptide Scientific Inc. (PSI), has developed a comprehensive process for the industrial-scale production of high-purity peptides, capable of producing 500 grams of material. This process, tailored for high-purity industrial mass production, establishes a reproducible, parameter-standardized, and GMP-compliant workflow, ensuring batch-to-batch consistency and compliance with stringent pharmaceutical standards.

The company's 500 grams grade industrial mass production process integrates an all-in-one workflow, including batch cleavage, solvent concentration, organic solvent precipitation, tangential flow ultrafiltration refining, chromatographic purification, and vacuum lyophilization. This process mitigates common scale-up challenges such as inhomogeneous reactions and residual impurities, stabilizing the production of peptide dry powder with a purity of 98% or above. The solution is applicable to API filing, commercial manufacturing, and high-end custom research scenarios.

The process begins with the precise selection and feeding of 500 grams of high-load solid-phase resin, with a resin substitution degree of 0.6 mmol/g and a total resin molar quantity of 0.3 mol. After synthesis, the total weight of peptide resin is approximately 1000 grams, with a target finished peptide output of 500 grams. To address the risks associated with large-volume cleavage reactions, the company adopts an equal batch cleavage strategy, dividing the 1000 grams of peptide resin into two independent batches, each processed at 500 grams. This method ensures uniform cleavage reactions and consistent product quality for each batch, significantly improving production stability and final product yield.

Following the cleavage process, the mixed cleavage solution is transferred to a concentration tank for vacuum concentration, removing approximately 2.5 liters of trifluoroacetic acid (TFA), the core acidic impurity in the system. This step greatly reduces the residual acidity of the system, preventing peptide chain degradation and excessive finished product acidity, thereby providing a pure material system for downstream precipitation and refinement procedures.

The concentrated peptide solution is then transferred to a precipitation tank, where diethyl ether is added at a material-to-precipitant ratio of 1:7, with a single-batch ether dosage of 17.5 liters. This process leverages the characteristic that peptides are insoluble in organic solvents while small-molecule impurities are soluble, allowing for the rapid aggregation and precipitation of the target peptide. This separation process efficiently removes the main peptide component from solvent residues, small-molecule by-products, and unreacted monomers, completing the preliminary purification and enrichment of the target peptide.

The solid-liquid mixture after precipitation is transferred to a PFD integrated machine for filtration, washing, and drying. All operations are automatically completed in a fully closed environment, including solid-liquid separation, repeated ether rinsing, and vacuum drying. This closed operation avoids cross-contamination and material loss, fully complying with GMP clean production specifications. Approximately 250 grams of dry crude peptide powder are obtained per batch. After the completion of two batches of cleavage and precipitation, the total crude peptide materials for mass production are fully collected.

The dried crude peptide is dissolved in purified water at a standard concentration of 20 mg/mL to prepare a homogeneous and stable crude peptide solution. Tangential Flow Filtration (TFF) is adopted to selectively remove residual TFA, small-molecule fragments, resin residues, and soluble impurities generated during the cleavage process. This procedure takes 2 to 4 hours and significantly increases the overall peptide purity to 85% or above, reducing the processing pressure of subsequent HPLC purification and improving overall production efficiency and product yield.

The crude peptide solution pretreated by primary ultrafiltration is then sent to the High-Performance Liquid Chromatography (HPLC) system for gradient elution and refinement. The target peptide is accurately separated from isomers, polar impurities, and degradation by-products, achieving high-purity enrichment. This procedure lasts 6 to 9 hours, and after precise chromatographic separation and purification, the purity of the target peptide is stably increased to 98% or above, meeting the quality standards for high-end peptide APIs and commercial finished products.

Secondary TFF ultrafiltration is applied for deep refinement, completely removing organic solvents and acidic residues in the system. This process further purifies the aqueous peptide solution, eliminating the risk of reduced finished product stability and safety caused by solvent residues. The procedure takes 2 to 3 hours, providing high-purity materials for lyophilization molding.

Finally, the deeply purified high-purity aqueous peptide solution is transferred to a vacuum lyophilizer for low-temperature drying and molding. The entire low-temperature process maximizes the integrity of the peptide molecular structure and avoids peptide chain degradation and activity loss caused by high temperatures. The total lyophilization cycle is about 2 days, and the final finished product is loose, stable, easily soluble, and storable high-purity peptide dry powder.

This comprehensive process ensures standardized parameters, graded purification, and full GMP compliance, delivering unmatched industrial reliability. The company's ability to provide end-to-end integrated solutions for peptide manufacturing underscores its commitment to advancing the field of high-purity peptide production.