RiteMED Ascorbic Acid Mechanism of Action

Pharmacology: Tablet: Vitamin C is a water-soluble antioxidant. It can quench various reactive oxygen and nitrogen species and thus, protects the body from damaging oxidizing agents.
Vitamin C is a cofactor for enzymes involved in important biological processes including synthesis of collagen, carnitine and neurotransmitters eg, norepinephrine and serotonin. It also facilitates the absorption of iron from the GIT.
Vitamin C is important in the defense against infection by enhancing immune function. It plays an important role in the body's response to stress.
Syrup: Ascorbic acid, a water soluble vitamin, is essential for the synthesis of collagen and intracellular material. Ascorbic acid deficiency develops when dietary intake is inadequate. It is rare in adults, but may occur in infants, alcoholics or elderly. Deficiency leads to the development of a well defined syndrome known as scurvy. Ascorbic acid has been used to acidify urine and has also been tried in the treatment of idiopathic methemoglobinemia and many other disorders but there is a little evidence of beneficial effect.
Pharmacokinetics: Tablet: Vitamin C is absorbed from the intestine via an active transport process that is saturable and dose dependent. At low concentrations in the GIT, active transport predominates while simple diffusion occurs at high concentrations.
Absorption is high (up to 70-90%) at doses of 30-180 mg/day; however, absorption falls to ≤50% with increasing doses >1 g/day.
The plasma half-life of ascorbic acid in humans is 16 days. However, in patients without vitamin C deficiency, excess ascorbate is eliminated rapidly with a half-life of 3.4 hrs.
Vitamin C and its metabolites are excreted primarily in the urine.
Syrup: Ascorbic acid is readily absorbed from the gastrointestinal tract and is widely distributed in the body tissues. It is reported to be about 25% bound to plasma proteins. The amount of ascorbic acid in the body is about 1.5 g. The concentration is higher in leukocytes and platelets than in erythrocytes and plasma. In deficiency states that the concentration in leukocytes declines later at a slower rate, and has been considered to be better criterion for the evaluation of deficiency than the concentration in plasma.