Product Name:
Vitamin A (Retinol)
CAS Number:
68-26-8 (all-trans Retinol)
Chemical Family / INCI Name:
Retinoid. INCI: Retinol
EC Number:
200-412-2
Common Form:
Yellow to orange crystalline powder or viscous oil solution (when esterified for stability)
Uses:
Vitamin A is a fat-soluble vitamin essential for numerous biological processes. It is widely used in pharmaceutical, cosmetic, and nutritional applications.
Primary Function and Applications:
· Primary Function: Cell growth regulator, vision support molecule, antioxidant, and skin conditioning agent
· Key Benefit: Essential for normal vision, immune function, cellular differentiation, and epithelial tissue maintenance
· Typical Applications:
· Pharmaceutical: Treatment and prevention of Vitamin A deficiency, night blindness, and xerophthalmia
· Cosmetic & Skincare: Anti-aging formulations to reduce fine lines, wrinkles, and improve skin texture
· Nutritional Supplements: Fortification of foods, dietary supplements, and animal feed
· Food Industry: Food additive for nutritional fortification (e.g., margarine, dairy products, cooking oils)
What does Vitamin A do in a formulation?
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Cell Regulation: As a ligand for retinoic acid receptors (RAR) and retinoid X receptors (RXR), it regulates gene expression controlling cell growth and differentiation
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Keratinization Control: Normalizes epidermal keratinization, reducing roughness and promoting smoother skin
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Collagen Synthesis: Stimulates fibroblast activity and collagen production, improving skin elasticity
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Visual Cycle Support: As retinal (aldehyde form), it combines with opsin to form rhodopsin, the visual pigment essential for low-light vision
Critical Safety & Handling Profile:
· Safety Note: Extremely sensitive to degradation. Retinol and its esters are rapidly destroyed by oxygen, light, heat, acids, and oxidizing agents
· Hazard Classification: Toxic (T) - R61 (May cause harm to the unborn child)
· Storage Conditions: Store under inert gas (nitrogen or argon) in tight, light-protected containers at -20°C
· Shelf Life:
· Powder form: Stable for 36 months at -20°C
· In solution: Use within 1 month at -20°C; avoid repeated freeze-thaw cycles
Technical profile:
Key Specifications & Physical Data (for all-trans Retinol):
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Property
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Values
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Appearance
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Yellow to orange crystalline powder
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Molecular Formula
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C20H30O
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Molecular Weight
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286.45 g/mol
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Purity (Assay)
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≥95% - ≥98% (by HPLC)
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Melting Point
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62 - 64 °C
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Boiling Point
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120 - 138 °C
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Density
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~0.95 g/cm³
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Solubility
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Soluble in DMSO (≥40-57 mg/mL), ethanol, chloroform, oils, and fats. Practically insoluble in water or glycerol
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Absorbance Ratio (A325 corr./A325)
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≥0.85 (pharmacopeial requirement)
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Acid Value
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≤2.0 mg KOH/g (for oil solutions)
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Peroxide Value
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Test Must pass (≤1.5 mL Na?S?O? for food grade)
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Heavy Metals (as Pb)
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≤20 ppm (pharma/food grade); ≤2 ppm (food additive)
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Technical Considerations:
1. Chemical Forms: Vitamin A exists in multiple forms with different stability profiles:
· Retinol (Alcohol form): Least stable, most biologically active
· Retinyl Acetate: Ester form, more stable than retinol
· Retinyl Palmitate: Most stable ester form, commonly used in commercial applications
· Retinal/Retinoic Acid: Oxidized metabolites with specific biological functions
2. Stability Protocol: Due to extreme sensitivity to degradation:
· Always handle under yellow light to prevent photodegradation
· Use freshly prepared solutions
· Incorporate antioxidants (e.g., BHT, vitamin E) in formulations
· For oil solutions, storage at -20°C in sealed ampoules under inert gas is recommended
3. Activity Units: Biological activity can be expressed in multiple units:
· 1 USP Unit = biological activity of 0.3 µg of all-trans retinol
· Activity may also be expressed in IU (International Units) or RE (Retinol Equivalents)
4. Quality Control: Pharmacopeial standards (USP, EP, JP) require specific identification tests including:
· Antimony trichloride test (transient blue color)
· TLC identification with RF values: alcohol form ~0.1, acetate ~0.45, palmitate ~0.7
· UV absorbance ratio requirements
5. Food Grade Specifications: For food additive applications, compliance with standards such as GB 14750-2010 is required, with assay limits of 97.0-103.0% of labeled vitamin A content .