methylcobalamin B12

1. PHARMACEUTICAL MICROBIOLOGY
RPD23602

LECTURER NAME:
DR. HENNY RACHDIATI

TITLE:
METHYLCOBALAMIN INJECTION (VITAMIN B12)


STUDENT NAME

MUHAMMAD AFIQ RAFI’UDDIN BIN AHMAD RAJI 57153313118
NURUL FATHINEE BINTI ABD RAZAK 57153313243
NURUL ATIRAH BINTI RANI 57153313142
WAN RASYIDAH BINTI WAN KAMARUDDIN 57153313020
VICKY LIONG WEI CHYI 57153313092
SYAZWANI BINTI JUNOH 57153313265

2. INTRODUCTION
Vitamin B12 Cobalamin

Vitamin commonly heard as the important part of our healthy diet. But does everyone
know the uses of vitamin itself. Vitamin is generally known substance that can be absorbed
from our dietary consumption. In order to increase the absorption or daily uptake of those
vitamins we offer take supplement such as vitamin c supplement. There are many types of
vitamin exist in the daily dietary that we consumed and our body tends to absorb the nutrients
and the vitamin contained in the diets. That’s why it is important to know what we consume
every day.
Generally, vitamin is classified into two classes: water soluble and fat soluble. Water
soluble vitamins are the folic acid, vitamin B12, B6, B1, B2, B3, vitamin C, Biotin,
Pantothenic Acid whereas fat soluble vitamins are the vitamin A, D, E, and K. The absorption
of each of these vitamins are fixed under Recommended daily allowance in dietary reference
intake of vitamin published by Food and Nutrition Board reference intake requirement
depends on age, body weight, diet and physiological status of an individual.
The vitamin that we are going to focus on is Vitamin B12 and Cobalamin. This type
of vitamin is water soluble vitamins. The rarest vitamin of all other water soluble type of
vitamin. Vitamin B12 commonly synthesized only by the certain microorganisms.
Sometimes, small amount of Vitamin B12 is synthesized by colon bacteria but the absorption
is negligible. As consideration for daily requirement, 2.4 Mg of vitamin B12 is needed. Most
of the vitamin B12 deficiency problems are mainly caused by the nonspecific mechanism.
Pernicious anaemia is an example and now treated with either large dose of oral vitamin B12
supplements or monthly injection of more control dose. This vitamin is injected into our body
by IM or IV injection. There are certain precautions and sterilization techniques used during
the preparation of injection to ensure there are zero contamination rates.

Preparation of Methylcobal® injection
Methylcobal® injection contains a sterile solution of 500μg Mecobalamin and 50mg D-
Mannitol in water for injections for 1 ampule. It is a clear, red liquid with the pH range 5.3-
7.3 and the osmotic pressure ratio about 1 relative to isotonic sodium chloride solution.
The active ingredient, Mecobalamin occurs as dark red crystals or an amorphous or
crystalline powder. It is sparingly soluble in water, slightly soluble in ethanol (99.5), and
practically insoluble in acetonitrile. Mecobalamin is affected by light and should be stored in
an amber glass ampoule.
D-mannitol is an osmotic diuretic that increase urine volume by increasing the amount of
osmotically active solute in urine and the osmolarity of plasma. D-mannitol is manufactured
by electrolytic reduction of glucose.
As for the water for injection (Syn. Aqua ad Injectabilia; Aqua pro Injectionibus) is a
sterilised distilled water free from pyrogens.

3. The manufacturing process should meet the requirements of good manufacturing practices
(GMP).

Main Tests for Vitamin B12 Deficiency
Four main tests:-
1. Serum B12
—The normal range is 200 to 900 pg/ml. (Please note that your B12 may have been measured
by another system – pmol/l so you should see the normal range described in your report.) If
your B12 is less than 150 it is very low. A good level is around 400. If a cynocobalamin
source is consumed these levels may be high but the B12 is still not usable by the body. In
this case its better to rely on one of the other two tests.
2. Homocysteine level
—High homocysteine levels are an indicator that the usable vitamin B12 is low, and should
be supplemented. If Serum B12 levels are normal but homocysteine is high (common in
people taking cynocobalamin supplements), a methylcobalamin supplement is necessary.
3. MMA
—Methylmalonic Acid, serum: MMA, along with homocysteine, helps diagnose an early or
mild B12 deficiency. If MMA and homocysteine levels are increased, then vitamin B12
deficiency may be present, indicating less available B12 at the tissue level. If only
homocysteine is elevated, then folic acid may be low or not being metabolism properly. If
MMA and homocysteine levels are normal, it is unlikely that there is a B12 deficiency.
4. Holotranscobalamin
—this test is not done everywhere and is expensive but it’s the best test because it measures
usable B12. Under normal circumstances Its alright to rely on Serum B12 if cynocobalamin
supplements are not being taken. Otherwise homocysteine levels are more reliable.
Alternatively both serum vitamin B12 and homocysteine levels can be tested

Serum Vitamin B12 Level
This test measures the amount of vitamin B12 in blood. This test is used to assess vitamin B12
deficiency due to poor dietary intake or problems absorbing vitamin B12.
• Optimal serum B12-Can be maintained with methylcobalamin injections administered
once per month.
• To inject methylcobalamin deeper when administering less frequent injections.
• The goal is to treat B12 deficiency and bring serum B12 levels to a good range.

4. Direction for methycobal injection


Dosage & Administration
Injection:
• Peripheral Neuropathies: The usual adult dosage is 1 amp, equivalent to 500 mcg of
mecobalamin administered IM or IV 3 times a week. The dosage should be adjusted
according to age of patient and severity of symptoms.
• Megaloblastic Anemia: The usual adult dosage is 1 amp, equivalent to 500 mcg of
mecobalamin administered IM or IV 3 times a week. After approximately 2 months of
medication, the dose should be reduced to a single administration of 1 amp at 1- to 3-
month intervals for maintenance therapy.


Special Precautions
• Discontinue medication with Methycobal if there is no response after several months.
Methycobal injection is susceptible to photolysis. It must be used promptly after the
package is opened and care must be taken not to expose the ampoule to direct light.
In IM administration, care should be exercised, suggested as follows, to avoid adverse
effects on tissues or nerves:
Repeated injection at the same site should be avoided. Particular care should be
exercised when administering Methycobal to neonates, premature infants, infants and
children.
The course of nerves should be avoided for the site of injection.
If the patient complains of pain or if blood reflux occurs when the syringe needle is
stuck, withdraw it immediately and try at a different site.
Methycobal injection is a one-point-cut type ampoule. It is recommended that the cut
point of the ampoule be wiped clean with an alcohol swab.

Mechanism of Action
Biochemically, mecobalamin is a B12 containing co-enzyme with an active methyl base. It
participates in transmethylation reactions and is the most active of all B12 homologs in the
body with respect to nucleic acid, protein and lipid metabolism. Methylcobal acts to repair
damaged nerve tissue in nerve disorders for the example axonal degeneration and
demyelination and it is involved in erythroblast maturation, promotion of erythroblast
division, and heme synthesis, thus, acting to improve the status of the blood in megaloblastic
anemia. Methylcobal is the first preparation with which it has been documented, double-blind
clinical trials, that mecobalamin is effective not only on megaloblastic anemia but also on
peripheral neuropathies. For example, diabetic neurological disorders and multiple neuritis.

5. Benefits and Uses
Methylcobalamin is the only active form of B12 founthe Central Nervous System (CNS).
Benefits of Methylcobalamin supplementation include;
 Assists in the reduction of elevated Homocysteine. Elevated Homocysteine has been
linked to increased cardiovascular risk of disease.
 Proven beneficial for symptoms of depression (i.e., supporting the production of
serotonin and melatonin)
 acts as a methyl donor and participates in the synthesis of SAM-e (S-
adenosylmethionine), a nutrient that has powerful mood elevating properties.
 Supports Immune system regulation
 Repair of damaged myelin sheath
 acts to reverse nerve damage and promote nerve cell regeneration
 Increased metabolic function
 Supports healthy red blood cells and is used to treat Anemia

Side Effects
 Irritation at the injection site and/or skin rash have been reported by some patients.
 It can cause allergic reaction: skin rash, itching or hives, swelling of the face.


Good Manufacture Practice
• Containers and closures handled in a manner to prevent contamination.
• Examination, approval of labels, labeling
• Strict control over labeling issue, and return to stock
• Written procedures, physical separation of labeling operations
• Examination of materials before use
• Inspection of facilities immediately before
• Tamper resistant packaging (for OTC products)
• Expiration dating
• Quarantine before release
• Store under appropriate conditions

6. Reference
 www.wisegeekhealth.com/what-are-the-most-common-methylcobalamin-side-
effects.htm
 http://www.defymedical.com/services/89-methylcobalamin-vitamin-b-12-
injection
 http://www.eisai.jp/medical/products/di/EPI/MBL_A_EPI.pdf
 http://www.medsafe.govt.nz/consumers/cmi/w/WaterforInjectionPfizer.pdf
 http://www.empowerrxpharmacy.com/drugs/methylcobalamin-vitamin-b12-
injection.html