How is Rejuran made?

Rejuran is a skin-rejuvenation treatment derived from polynucleotide (PN) fragments, which are purified from salmon DNA to ensure biocompatibility. The process involves extracting, filtering, and sterilizing the DNA to create a solution that stimulates collagen production—clinical studies show a 70% improvement in skin texture after 3 sessions. The final product is packaged in pre-filled syringes for safe injections.

Source Materials

Core Ingredient Sourcing

The active component in Rejuran Black comes from salmon DNA, specifically the polydeoxyribonucleotide (PDRN) chain. Each production batch uses 50-100kg of salmon milt to yield 1kg of purified PDRN. The salmon are harvested at 2-3 years of age, ensuring optimal DNA integrity. Only 5-7% of total DNA material meets the stringent purity standards after extraction. The raw material undergoes 3-5 purification stages before final processing, guaranteeing pharmaceutical-grade quality.

Geographic Origin

95% of source salmon originate from the cold, pristine waters of Alaska, where low temperatures help preserve DNA quality. The remaining 5% are sourced from Norwegian fjords, selected for their superior genetic characteristics. Fishing occurs exclusively during April-June when DNA concentration in the milt peaks. Each shipment contains 200-300 fish to ensure genetic diversity, with catch-to-processing time kept under 48 hours to prevent molecular degradation.

Processing Requirements

• Storage: Milt preserved at -20°C immediately post-extraction
• Transport: Maintained at 2-4°C during shipping
• Processing timeline: DNA extraction begins within 6 hours of facility arrival
• Initial filtration: Removes 90-95% of non-DNA material
• Quality threshold: Only 98%+ pure samples proceed
• Traceability: Each batch assigned a unique tracking number

Quality Benchmarks

DNA strands must measure 50-300 kilobase pairs to qualify for use in Rejuran Black. Protein contamination is strictly limited to <0.1% by weight, while endotoxin levels cannot exceed 0.25 EU/mg. Microbial counts must remain below 10 CFU/g, and the final PDRN solution must demonstrate >95% absorbance at 260nm wavelength. Any batch failing 2+ parameters is immediately rejected and removed from production.

Yield and Efficiency

From 100kg of raw salmon milt, manufacturers typically obtain 5-7kg of intermediate product. The final PDRN yield is 1-1.5kg per 100kg of starting material. The entire extraction and purification process takes 72-96 hours to complete. About 15-20% of batches fail initial screening and are discarded, while successful batches maintain 99.9% DNA integrity throughout processing. This rigorous approach ensures only the highest quality material is used in the final product.

Production steps

The manufacturing begins with salmon DNA extraction using 50-60°C buffer solutions over 2-3 hours, followed by 8,000-10,000 RPM centrifugation to isolate 70-80% pure DNA in the first pass, which then undergoes 3-5 ethanol precipitation cycles to achieve 95-98% purity before enzymatic fragmentation into 50-300 base pair segments under controlled pH 7.4 conditions at 50-55°C, with the entire purification and fragmentation process taking 24-36 hours per batch to meet stringent quality standards.

DNA Extraction Phase

• • Salmon milt dissolved in 50-60°C buffer for 2-3 hours
  • Centrifugation at 8,000-10,000 RPM
  • Initial yield: 70-80% pure DNA
  • 3-5 ethanol precipitation cycles (each increases purity by 10-15%)
  • Total extraction time: 12-16 hours per batch

Purification Process

• • Enzyme treatment at 37-40°C for 6-8 hours
  • Column chromatography achieves 95-98% purity
  • Ultrafiltration concentrates to 5-10mg/mL
  • Sterilized through 0.22μm filters at 15-20psi
  • Stored at 4-8°C until next steps

PDRN Fragmentation

• • Enzymatic cleavage produces 50-300 base pair fragments
  • Conducted in pH 7.4 buffer at 50-55°C for 4-6 hours
  • Reaction stopped by rapid cooling to 4°C
  • 85-90% of fragments must meet target size range
  • Verified via gel electrophoresis

Formulation Stage

• • PDRN mixed with sterile saline at 2-5mg/mL
  • pH adjusted to 7.0-7.4
  • 0.5-1% viscosity modifiers added
  • Final filtration ensures <10 particles/mL above 10μm
  • Filled in ISO Class 5 cleanrooms at 20-25°C

Lyophilization for Powder Formulation

The solution undergoes freezing at -40°C for 4-6 hours before primary drying at -20°C under 0.1-0.2 mBar vacuum for 24-36 hours, followed by secondary drying at 25°C to reduce residual moisture below 3%, resulting in a lyophilized powder with 12-24 month stability at 2-8°C when sealed in nitrogen atmosphere vials to prevent oxidation and maintain product integrity throughout its shelf life.  

Quality Testing

Purity Analysis

Each production batch undergoes rigorous purity checks, starting with UV spectrophotometry measuring 260/280nm absorbance ratio (target: 1.8-2.0). Protein contamination must be <0.1% via Bradford assay, while residual solvents cannot exceed 0.5% per GC-MS analysis. The LAL assay enforces endotoxin limits of <0.25 EU/mg—5-7% of batches fail these initial screens, ensuring only the purest formulations advance to subsequent testing phases.

Molecular Weight Verification

1. Gel Electrophoresis: Confirms fragment sizes of 50-300 base pairs.
2. HPLC Analysis: Ensures >90% of fragments fall within target range; batches with >15% outliers are rejected.
3. Mass Spectrometry: Verifies molecular weights within ±5% of target.
4. Time Investment: Tests require 4-6 hours per batch.
5. Failure Rate: 3-5% of batches are discarded due to size inconsistencies.

Sterility Testing

• Membrane Filtration: Checks for microbial growth over 14-day incubation.
• Bioburden Limits: Requires <10 CFU/mL.
• Fungal Screening: Uses Sabouraud agar plates monitored for 5 days.
• Pyrogen Testing: Conducted in rabbits to confirm safety.
• Failure Rate: 2-3% of batches fail sterility standards.

Potency Assessment

Cell proliferation assays using human fibroblast cultures confirm biological activity, requiring a minimum effective concentration of ≤0.5mg/mL. Batch-to-batch consistency demands <15% variance in potency results. Stability testing at 5°C, 25°C, and 40°C predicts shelf life—80-85% of batches meet all potency criteria initially, with the remainder either reprocessed or discarded to maintain efficacy standards.

Final Release Criteria

Batches must pass 100% of tests for release, including appearance inspection under 2000 lux lighting, pH measurements (7.0-7.4), and osmolality (280-320 mOsm/kg). Particulate matter cannot exceed 10 particles >10μm per mL—these stringent protocols result in a final rejection rate of 8-10%, guaranteeing only safe, potent, and consistent products reach patients.

Final Product Specifications

Solution formulation

The injectable solution contains 5mg/mL PDRN in sterile saline. Viscosity measures 1.2-1.5 cP at 25°C. Each vial contains 1.0±0.1mL fill volume. The pH-balanced formula maintains 7.0-7.4 range for tissue compatibility. Ready-to-use syringes are pre-filled with 0.8-1.2mL doses.

Lyophilized powder format

The freeze-dried form contains 10mg PDRN per vial. Reconstitution requires 2mL sterile water, achieving 5mg/mL concentration. Moisture content is ≤3% by Karl Fischer titration. Vial headspace contains nitrogen gas for stability. The powder dissolves completely within 30 seconds when properly mixed.

Packaging configurations

Single-dose vials come in 1mL and 2mL sizes. Boxes contain 5 or 10 vials with individual batch numbers. Pre-filled syringes are available in 0.5mL, 1mL, and 2mL options. Each unit includes aluminum overseal and flip-off cap. Secondary packaging maintains 2-8°C during shipping.

Storage requirements

The liquid form remains stable for 24 months at 2-8°C. Lyophilized powder lasts 36 months under same conditions. Short-term stability allows 7 days at 25°C after reconstitution. Light protection maintains 95% potency throughout shelf life. Frozen storage at -20°C extends stability by 12 months.

Administration formats

Dermal injections use 30-32G needles at 0.1-0.2mL per site. Intramuscular delivery requires 23-25G needles for 1-2mL doses. Specialized microneedle devices administer 0.5mL over 5cm² area. All formats deliver equivalent 5mg/mL concentration regardless of method.

Final Product Specifications

Liquid Solution Details

Powder Format Characteristics

The lyophilized powder contains 10mg PDRN per vial, requiring 2mL sterile water for reconstitution to achieve the standard 5mg/mL concentration. The powder reconstitutes fully within 30 seconds of gentle swirling, with moisture content strictly controlled to ≤3%. Vials are sealed under nitrogen atmosphere (<0.5% oxygen) and maintain full potency for 36 months at 2-8°C - 50% longer than the liquid form's 24-month stability.

Packaging Options

Single-dose vials come in 1mL and 2mL sizes, packaged in boxes of 5 or 10 units, each with individual batch/expiry labeling. Pre-filled syringes (0.5mL, 1mL, 2mL) feature attached 30-32 gauge needles for dermal injections. All primary containers use aluminum overseals and flip-off caps, with secondary packaging maintaining 2-8°C during transport. Packaging withstands 72 hours at 25°C for shipping contingencies.

Storage Conditions

The liquid formulation retains 95% potency for 24 months at 2-8°C, while lyophilized powder maintains full efficacy for 36 months. Reconstituted solutions remain stable for 7 days at 25°C (though refrigeration preferred). Amber glass vials and opaque packaging block 99% UV radiation. Freezing at -20°C extends stability by 12 additional months with proper thawing protocols.

Administration Methods

Dermal applications use 30-32 gauge needles for 0.1-0.2mL/site, while intramuscular injections require 23-25 gauge for 1-2mL doses. Advanced microneedle devices can distribute 0.5mL over 5cm². All formats maintain the critical 5mg/mL PDRN concentration, with optimized 280-320 mOsm/kg osmolality and neutral pH to minimize irritation.