Methylcobalamin is an organic compound with chemical formula Csixty-threeHninety-oneCoNthirteenOfourteenP，It is an endogenous vitamin B12, which exists in blood and medullary fluid and can pass through the blood-brain barrier without biotransformation. It can be used to treat or prevent vitamin B12 deficiency and its complications.After taking, mecobalamin can replace endogenous vitamin B12, increase the level of vitamin B12, and improve vitamin B12 deficiency.Vitamin B12 is necessary for hematopoiesis, nerve metabolism, DNA and RNA generation, carbohydrate, fat and protein metabolism, helps to improve the function of iron in the metabolic cycle, and assists folic acid in choline synthesis[1]。
Chinese name
Mecobalamin
Foreign name
methylcobalamin
alias
CO α - [α - (5,6-dimethylbenzimidazolyl)] - β methylcobalamide | mecobalamin VB12 raw powder | methyl vitamin B[2]
chemical formula
Csixty-threeHninety-oneCoNthirteenOfourteenP
molecular weight
one thousand three hundred and forty-four point three eight two
CAS registration
13422-55-4
melting point
190 ℃[2](Disassembly)
Water solubility
Slightly soluble in water or ethanol, almost insoluble in acetonitrile, lactone or acetonitrile[3]
atlas
Science popularization in China
Committed to authoritative science communication
The certification expert of this term is
Zhang Zheng|Pharmacist in charge
Pharmacy Department of Beijing Chaoyang Hospitalto examine
Qiu Kui|Deputy Chief Pharmacist
Pharmacy Department of Beijing Chaoyang Hospitalto examine
The light shielding requirement is not more than 5lx[3]
Calculate chemical data
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Number of hydrogen bond donors: 9
Number of hydrogen bond receptors: 20
Number of rotatable chemical bonds: 26
Number of tautomers: 128
Topological molecule polar surface area (TPSA): 452
Number of heavy atoms: 92
Surface charge: 0
Complexity: 3150
Number of isotope atoms: 0
Determine the number of atomic structure centers: 13
Number of uncertain atomic structure centers: 1
Determine the number of chemical bond stereocenters: 3
Number of uncertain chemical bond structure centers: 0
Number of covalent bond units: 3[2]
Brief Introduction to Drugs
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pharmacological action
Methylcobalamin is an endogenous coenzyme Btwelve, participate in one carbon unit cycle and play an important role in the process of methionine synthesis from homocysteine.Animal experiments found that this product was easier to enter the neuronal organelles than cyanocobalamin, participated in the synthesis of thymidine in brain cells and spinal cord neurons, promoted the utilization of folic acid and nucleic acid metabolism, and promoted the synthesis of nucleic acid and protein better than cyanocobalamin;This product can promote axon transport function and axon regeneration, normalize the transport of axon skeleton protein of sciatic nerve in streptozotocin induced diabetic rats;It can inhibit the neurodegeneration caused by drugs, such as neurodegeneration caused by adriamycin, acrylamide, vincristine, and neuropathy in spontaneously hypertensive rats.It was found in rat tissue culture that this product can promote the synthesis of lecithin and the formation of neuronal myelin sheath.This product can reduce the delayed synaptic neurotransmitter and return to normal. It can restore the acetylcholine in the brain of rats fed with choline deficiency feed to normal level by improving the excitability of nerve fibers to restore the ultimate plate potential induction.
indication
peripheral neuropathy [4]。
taboo
It is forbidden to use in patients with a history of allergy to mecobalamin or any excipient in the prescription[4]。
Adverse reactions
Skin rash, headache, fever, sweating, intramuscular injection site pain and induration were occasionally seen.May cause serious allergic reactions such as decreased blood pressure and dyspnea.
Toxicity and ecology
Toxicological data of mecobalamin:
Acute toxicity: oral LD50 of mice:>5000 mg/kg;Oral LD50 of rats:>5000 mg/kg.
Main irritant effects: It may cause inflammation on the skin and eyes, and there is no known sensitization effect.
Mecobalamin ecological data:
Generally, it is slightly harmful to water bodies. Do not contact undiluted or large quantities of products with groundwater, waterways or sewage systems. Do not discharge materials into the surrounding environment without government permission[2]。
Note: The above contents are only for introduction. Drug use must be carried out by regular hospitals under the guidance of doctors.
Pharmacopoeia information
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identify
(1) Take about 1mg of this product, add about 50mg of potassium bisulfate, place it in a crucible, burn it until molten, cool it, add 3ml of water, boil it until dissolved, add 1 drop of phenolphthalein indicator solution, add sodium hydroxide test solution to show light red, add 0.5ml of sodium acetate, 0.5ml of dilute acetic acid and 0.5ml of 0.2% sodium 1-nitro-2-naphthol-3, 6-disulfonate solution to show red or orange red;Add 0.5ml hydrochloric acid, boil for 1 minute, and the color will not disappear.
(2) In the chromatogram recorded under the content determination item, the retention time of the main peak of the test solution should be consistent with the retention time of the main peak of the reference solution.
(3) Operation in dark.Take an appropriate amount of this product and the reference solution respectively, add water to dissolve and dilute them to make a solution containing about 50 μ g per 1ml, and determine it by ultraviolet visible spectrophotometry (general rule 0401). The absorption spectrum of the test solution within the wavelength range of 220~550nm should be consistent with that of the reference solution.
(4) The infrared absorption spectrum of this product should be consistent with the control spectrum (spectrum collection 732 figure).[3]
inspect
Clarity of solutionTake 20mg of this product, add 10ml of water to dissolve it, and then the solution should be clarified (General Rule 0902, Method 1).
Related substancesDetermine according to the method of high performance liquid chromatography (general rule 0512).Operation in dark.
Test solution Take an appropriate amount of this product, add mobile phase to dissolve it and dilute it quantitatively to make a solution containing about 0.5mg per 1ml.
The control solution precisely measures 1ml of the test solution, places it in a 100ml volumetric flask, dilutes it to the scale with mobile phase, and shakes it up.
System suitability solution Take about 5mg of methylpyrrolidine reference substance, add 5.0ml of 1mol/L hydrochloric acid solution, keep away from light for 1h, immediately add 5.0ml of 1mo/L sodium hydroxide solution, and shake well.
Chromatographic conditions: octadecyl alkyl bonding glue is used as filler (Luna C18 spectrum, 4.6mmx250mm, 5 μ m or equivalent chromatographic column);Use 0.03mo/L dihydrogen phosphate bell solution (adjust the pH value to 4.5 with 0.2mol/L sodium hydroxide solution or phosphoric acid) - acetonitrile (84:16) as the mobile phase, and the detection wavelength is 342nm;Injection volume 20 μ l.
The system suitability requires that in the system suitability solution color chart, the retention time of the methylpyrrolidine peak is about 13 minutes, and the separation degree between the methylpyrrolidine peak and the impurity peak with a relative retention time of about 1.16 should be greater than 3.0.
Determination method Precisely measure the test solution and the reference solution, respectively inject them into the liquid chromatograph, and record the retention time of the chromatogram to the main component chromatographic peak by 3 times.
If there is an impurity peak in the chromatogram of the limit test solution, the area of a single impurity peak shall not be greater than 0.5 times (0.5%) of the soil peak area of the control rolling solution, and the sum of the impurity peak areas shall not be greater than 2 times (2.0%) of the main peak area of the control rolling solution.
water contentTake this product and measure it according to the moisture determination method (General Rule 0832, Method 1). The moisture content should not exceed 12.0%.[3]
Assay
Determine according to the method of high performance liquid chromatography (general rule 0512).Operation in dark.
Test solutionTake an appropriate amount of this product, weigh it precisely, add mobile phase to dissolve it and dilute it quantitatively to prepare a solution containing about 50 μ g per 1ml.
Reference solutionTake an appropriate amount of mezuramine reference substance, weigh it precisely, add mobile phase to dissolve it and dilute it quantitatively to prepare a solution containing about 50 μ g per 1ml.
System suitability Solution, chromatographic conditions and system suitability requirementsSee related substances.
AssayAccurately measure the test solution and the reference solution, respectively inject them into the liquid chromatograph, and record the chromatogram.Calculate by peak area according to external standard method.[4]
category
Drugs for peripheral neuropathy[3]。
security information
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Safety terminology
S24/25：Avoid contact with skin and eyes.
Avoid skin and eye contact.
S26：In case of contact with eyes, rinse immediately withplenty of water and seek medical advice.
After eye contact, immediately flush with plenty of water and seek medical advice.
S36：Wear suitable protective clothing.
Wear appropriate protective clothing.
Risk terminology
R36/37/38：Irritating to eyes, respiratory system and skin.
