Pyridoxine Hydrochloride, Pyridoxine HCl, Vitamin B6, 58-56-0
VITAMIN B6 (PYRIDOXINE HCL)
& PYRIDOXINE vs PYRIDOXINE HCL – COMPARISON GUIDE
PART 1: VITAMIN B6 (PYRIDOXINE HCL) – TECHNICAL DATA SHEET
1. CHEMICAL IDENTITY AND DEFINITION
| Parameter |
Information |
| Chemical Name |
Pyridoxine Hydrochloride |
| Other Names |
Vitamin B6, Pyridoxine HCl, 2-Methyl-3-hydroxy-4,5-di(hydroxymethyl)pyridine Hydrochloride |
| CAS Number |
58-56-0 |
| EC Number (EINECS) |
200-386-2 |
| Chemical Formula |
C₈H₁₁NO₃ · HCl |
| Molecular Weight |
205.64 g/mol |
| Appearance |
White to off-white crystalline powder |
| Odor |
Odorless |
| Solubility |
Soluble in water, slightly soluble in ethanol |
| Vitamin Class |
Water-soluble vitamin (B-complex) |
2. PHYSICAL AND CHEMICAL PROPERTIES
| Property |
Value |
| Appearance |
White to off-white crystalline powder |
| Chemical Formula |
C₈H₁₁NO₃ · HCl |
| Molecular Weight |
205.64 g/mol |
| CAS Number |
58-56-0 |
| Melting Point |
~206 – 210 °C (decomposes) |
| Solubility in Water (20°C) |
~220 g/L |
| Solubility in Ethanol |
Slightly soluble |
| pH (Aqueous Solution, 1%) |
~2.5 – 3.5 (acidic) |
| Odor |
Odorless |
| Stability |
Sensitive to light, stable to heat |
| Storage |
Protected from light, dry environment |
3. CHEMICAL STRUCTURE
Chemical Structure:
Pyridoxine is a form of vitamin B6 containing hydroxyl and hydroxymethyl groups on a pyridine ring.
IUPAC Name: 4,5-Bis(hydroxymethyl)-2-methylpyridin-3-ol hydrochloride
SMILES: CC1=NC=C(CO)C(CO)=C1O.Cl
CH₂OH
|
HO ─ C ─ C ─ CH₂OH
| |
H₃C ─ C ─ C ─ H
| |
N OH
|
HCl
4. VITAMIN B6 FORMS
| Type |
Description |
| Pyridoxine HCl |
Most common synthetic form; stable and inexpensive |
| Pyridoxal |
Active form; enzyme cofactor |
| Pyridoxamine |
Active form; enzyme cofactor |
| Pyridoxal 5'-Phosphate (PLP) |
Biologically most active form |
5. FUNCTIONS IN THE BODY
| Function |
Description |
| Protein and Amino Acid Metabolism |
Amino acid synthesis, transamination, and deamination |
| Nervous System |
Neurotransmitter synthesis (serotonin, dopamine, GABA) |
| Hemoglobin Synthesis |
Plays a role in hemoglobin production |
| Immune System |
Lymphocyte production and immune function |
| Hormone Metabolism |
Metabolism of steroid hormones |
| Carbohydrate Metabolism |
Glycogenolysis and gluconeogenesis |
6. BENEFITS
| Benefit |
Description |
| Nervous System |
Regulates nerve transmission, supports neurotransmitter synthesis |
| Mood Support |
Improves mood through serotonin and dopamine synthesis |
| Anemia Prevention |
Plays a role in hemoglobin synthesis |
| Immune Support |
Supports production of immune cells |
| Heart Health |
Regulates homocysteine levels |
| Hormonal Balance |
Plays a role in hormone metabolism |
| Protein Metabolism |
Supports amino acid metabolism |
7. DEFICIENCY SYMPTOMS
| System |
Symptoms |
| Nervous System |
Peripheral neuropathy, numbness, tingling, depression, anxiety |
| Hematological |
Microcytic anemia (small red blood cells) |
| Skin |
Dermatitis, dandruff, cracked mouth corners (angular cheilitis) |
| Immune |
Decreased immune function |
| Cognitive |
Confusion, memory problems |
8. SOURCES
| Source |
Description |
| Meat and Poultry |
Chicken, turkey, beef |
| Fish |
Salmon, tuna, cod |
| Organ Meats |
Liver, kidney |
| Whole Grains |
Wheat, oats, brown rice |
| Legumes |
Chickpeas, lentils, beans |
| Nuts and Seeds |
Sunflower seeds, walnuts |
| Vegetables |
Potatoes, bananas, spinach |
| Fruits |
Avocado, banana |
9. RISK GROUPS
| Group |
Reason |
| Elderly individuals |
Reduced absorption and dietary intake |
| Alcohol dependents |
Impaired absorption and storage |
| Kidney failure patients |
Vitamin loss |
| Autoimmune diseases |
Malabsorption |
| Pregnant women |
Increased need |
| Long-term medication users |
Isoniazid, penicillamine, oral contraceptives |
10. TREATMENT AND DOSAGE
| Parameter |
Information |
| Daily Requirement (Adult) |
1.3 – 1.7 mg |
| Pregnancy |
1.9 mg |
| Breastfeeding |
2.0 mg |
| Deficiency Treatment |
50 – 100 mg/day (under medical supervision) |
| Upper Safe Limit |
100 mg/day (adult) |
| Normal Blood Level (PLP) |
20 – 100 nmol/L |
11. SAFETY AND SIDE EFFECTS
| Parameter |
Information |
| Toxicity |
Low; excess excreted in urine |
| Oral LD50 (Rat) |
~4,000 – 5,000 mg/kg |
| Side Effects |
High doses (>200 mg/day) may cause neuropathy |
| Allergy |
Rare |
| Drug Interactions |
Isoniazid, penicillamine, levodopa |
12. IMPORTANT PRECAUTIONS
| Warning |
Description |
| Neurotoxicity |
Very high doses (>200 mg/day) may cause nerve damage |
| Drug Interactions |
Isoniazid and penicillamine may cause B6 deficiency |
| Levodopa Interaction |
B6 may reduce the effectiveness of levodopa |
| Long-term Use |
Peripheral neuropathy risk with high-dose long-term use |
13. REGULATORY STATUS
| Region / Authority |
Status |
| EFSA |
Daily reference intake established |
| FDA |
Daily Value (DV) 1.7 mg |
| Turkey |
Approved as food supplement |
| Codex |
Approved for food supplements and fortification |
14. OTHER NAMES AND SYNONYMS
| Type |
Name |
| Turkish Names |
B6 Vitamini, Piridoksin Hidroklorür |
| English Names |
Vitamin B6, Pyridoxine Hydrochloride, Pyridoxine HCl |
| CAS Number |
58-56-0 |
15. SUMMARY AND CRITICAL WARNINGS
| Parameter |
Value |
| Product |
Vitamin B6 (Pyridoxine HCl) |
| CAS Number |
58-56-0 |
| Formula |
C₈H₁₁NO₃ · HCl |
| Appearance |
White crystalline powder |
| Primary Function |
Protein metabolism, nervous system, immunity |
CRITICAL WARNINGS
1. NEUROTOXICITY RISK: Doses above 200 mg/day may cause peripheral neuropathy. Do not exceed recommended doses.
2. DRUG INTERACTIONS: Isoniazid (tuberculosis medication) and penicillamine may cause B6 deficiency.
3. LEVODOPA INTERACTION: B6 may reduce the effectiveness of levodopa used in Parkinson's disease.
4. EXCESS GENERALLY HARMLESS: Excess B6 is excreted in urine but very high doses can be neurotoxic.
5. PREGNANCY: Requirement increases during pregnancy. Supplementation should be under medical supervision.
6. STORAGE: Store in a dry, cool place protected from light.
7. NUTRITION: A balanced diet generally provides adequate B6. Risk groups may benefit from supplementation.
PART 2: VITAMIN B6 COMPARISON – PYRIDOXINE (CAS 65-23-6) vs PYRIDOXINE HCL (CAS 58-56-0)
1. GENERAL OVERVIEW
Both Pyridoxine and Pyridoxine Hydrochloride are forms of Vitamin B6. However, there are significant differences between them in terms of chemical structure, solubility, stability, and applications.
| Feature |
Pyridoxine (Vitamin B6) |
Pyridoxine HCl (Vitamin B6 HCl) |
| CAS Number |
65-23-6 |
58-56-0 |
| Chemical Formula |
C₈H₁₁NO₃ |
C₈H₁₁NO₃ · HCl |
| Molecular Weight |
169.18 g/mol |
205.64 g/mol |
| Form |
Free base |
HCl salt |
| Appearance |
White to off-white crystalline powder |
White to off-white crystalline powder |
| Odor |
Slight characteristic |
Odorless |
2. CHEMICAL STRUCTURE COMPARISON
Pyridoxine (Free Base)
CH₂OH
|
HO ─ C ─ C ─ CH₂OH
| |
H₃C ─ C ─ C ─ H
| |
N OH
Pyridoxine HCl (Hydrochloride Salt)
CH₂OH HCl
|
HO ─ C ─ C ─ CH₂OH
| |
H₃C ─ C ─ C ─ H
| |
N OH
Difference: Pyridoxine HCl is formed by the addition of a hydrochloride (HCl) group to the pyridoxine molecule.
3. PHYSICAL AND CHEMICAL PROPERTY COMPARISON
| Property |
Pyridoxine (65-23-6) |
Pyridoxine HCl (58-56-0) |
| Molecular Weight |
169.18 g/mol |
205.64 g/mol |
| Melting Point |
159-162°C (decomposes) |
206-210°C (decomposes) |
| pH (1% solution) |
5.0-6.0 |
2.5-3.5 (acidic) |
| Water Solubility (20°C) |
~3.4 g/L (slightly) |
~220 g/L (high) |
| Ethanol Solubility |
Soluble |
Slightly soluble |
| Fat Solubility |
Insoluble |
Insoluble |
| pKa |
5.0, 8.9 |
~5.0 (salt form) |
| Log P (Octanol-Water) |
-0.76 |
-0.76 (similar) |
| Light Sensitivity |
Sensitive |
Sensitive |
| Hygroscopicity |
Low |
Moderate (moisture-absorbing) |
| Stability |
Sensitive to light, stable to heat |
Sensitive to light, stable to heat |
4. APPLICATION COMPARISON
| Application |
Pyridoxine (65-23-6) |
Pyridoxine HCl (58-56-0) |
| Dietary Supplements |
✅ Used (less common) |
✅ Most commonly used |
| Pharmaceutical Formulations |
❌ Rare |
✅ Common |
| Food Fortification |
❌ Rare |
✅ Common |
| Liquid Formulations |
⚠️ Low solubility |
✅ High solubility |
| Injectable Solutions |
❌ Not suitable |
✅ Suitable |
| Powder Blends |
✅ Suitable |
✅ Suitable |
| Tablets / Capsules |
✅ Suitable |
✅ Suitable |
| Aqueous Solutions |
⚠️ Limited |
✅ Ideal |
5. ADVANTAGE AND DISADVANTAGE COMPARISON
5.1. Pyridoxine (65-23-6)
| Advantages |
Disadvantages |
| Higher biological activity (100% B6 activity) |
Low water solubility |
| Less acidic (pH 5.0-6.0) |
Difficult to dissolve in aqueous formulations |
| Higher purity level |
Limited formulation flexibility |
| Less hygroscopic |
More expensive |
5.2. Pyridoxine HCl (58-56-0)
| Advantages |
Disadvantages |
| Very high water solubility (220 g/L) |
Acidic pH (2.5-3.5) |
| High formulation flexibility |
Lower B6 activity (82.3%) |
| More stable and longer shelf life |
Hygroscopic (moisture-absorbing) |
| More economical |
pH adjustment required in aqueous solutions |
| Suitable for injections and liquid forms |
- |
6. SOLUBILITY COMPARISON (20°C)
| Solvent |
Pyridoxine |
Pyridoxine HCl |
| Water |
~3.4 g/L (low) |
~220 g/L (high) |
| Ethanol |
Soluble |
Slightly soluble |
| Methanol |
Soluble |
Soluble |
| Propylene Glycol |
Slightly soluble |
Soluble |
| Fats |
Insoluble |
Insoluble |
7. BIOLOGICAL ACTIVITY COMPARISON
| Parameter |
Pyridoxine |
Pyridoxine HCl |
| Vitamin B6 Activity |
100% |
~82.3% |
| Conversion to Active Form |
Converts to PLP |
Converts to PLP |
| Bioavailability |
High |
High |
| Absorption |
Good |
Good (faster dissolution) |
| Tissue Distribution |
All tissues |
All tissues |
Note: Both forms are converted to the active form Pyridoxal-5-Phosphate (PLP) in the body. Both are effective forms of vitamin B6.
8. APPLICATION AREA COMPARISON
| Application |
Pyridoxine |
Pyridoxine HCl |
| Dietary Supplements |
Used |
Most commonly used |
| Infant Formula |
Rare |
Common |
| Enteral Nutrition |
Rare |
Common |
| Parenteral Nutrition |
Not suitable |
Suitable |
| Cosmetics |
Used |
More common |
| Animal Feed |
Rare |
Common |
9. STORAGE COMPARISON
| Parameter |
Pyridoxine |
Pyridoxine HCl |
| Storage Temperature |
15-25°C |
15-25°C |
| Moisture Sensitivity |
Low |
Moderate-high (hygroscopic) |
| Light Sensitivity |
High |
High |
| Shelf Life |
24-36 months |
24-36 months |
| Packaging Requirement |
Light-proof |
Light-proof, moisture-proof |
10. SELECTION GUIDE
| If you need... |
Choose... |
| Aqueous solution preparation |
Pyridoxine HCl |
| Injectable formulation |
Pyridoxine HCl |
| Higher stability |
Pyridoxine HCl |
| Higher B6 activity |
Pyridoxine |
| Neutral pH |
Pyridoxine |
| Lower cost |
Pyridoxine HCl |
| Tablet/capsule form |
Both are suitable |
| Food fortification |
Pyridoxine HCl |
| Cosmetic formulation |
Pyridoxine HCl |
| Non-hygroscopic form |
Pyridoxine |
11. SUMMARY TABLE
| Property |
Pyridoxine (65-23-6) |
Pyridoxine HCl (58-56-0) |
| Form |
Free base |
HCl salt |
| Water Solubility |
Low (3.4 g/L) |
High (220 g/L) |
| pH (1%) |
5.0-6.0 |
2.5-3.5 |
| B6 Activity |
100% |
82.3% |
| Hygroscopic |
No |
Yes |
| Injectables |
No |
Yes |
| Cost |
High |
Low |
| Usage Frequency |
Less common |
More common |
| Preferred For |
Specialty applications |
General use |
CONCLUSION
-
For aqueous solutions, injections, and low-cost applications: Choose Pyridoxine HCl.
-
For higher B6 activity, neutral pH, and non-hygroscopic form: Choose Pyridoxine.
IMPORTANT DISCLAIMER: This Technical Data Sheet (TDS) is for informational purposes only and is prepared based on available technical data. This document is not a substitute for medical advice. For any health condition or suspected deficiency, consult a healthcare professional. For complete safety, storage, use, and regulatory compliance information, refer to the official documentation provided by the manufacturer/supplier.
