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Phar 722 Pharmacy Practice III


Chemical and Engineering News, Indians in Canada used birch bark tea for scurvy, ... Dr. James Lind, a British naval surgeon, reported on an experiment where he ... – PowerPoint PPT presentation

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Title: Phar 722 Pharmacy Practice III

Phar 722Pharmacy Practice III
  • Vitamins-
  • Ascorbic Acid (C)
  • Spring 2006

Ascorbic Acid (C) Study Guide
  • The applicable study guide items in the Vitamin
  • History
  • Structures of both forms
  • Salt formation
  • Major routes of degradation and how to minimize
  • Metabolic functions
  • Deficiency condition
  • Use of ascorbic acid esters
  • Commercial forms of the vitamin

Ascorbic Acid History-1
  • In this best-fed nation in the world, one-third
    to one-half of the population lacks vitamin C.
    This vital food element-essential for vigor and
    efficiency-is now available in a new
    mass-produced synthetic form. Technicians have
    developed successful manufacturing processes
    based on combining ascorbic acid and sodium in
    water-free methyl alcohol. The new vitamin C is
    precipitated as a pure, white crystalline mass.
  • Scientific American, reprinted from an article
    published November 1946, November, 275 (5) 10,

Ascorbic Acid History-2
  • 1498 - After about 10 weeks as sea, Vasco da
    Gama's crew experienced a new illness which
    caused ...their feet and hands swelling and their
    gums growing over their teeth so they could not
  • The crew recovered within a week after eating
    oranges purchased in East African ports.
  • The illness reoccurred on the voyage back which,
    again, responded to fresh oranges. About half
    the crew died at sea from scurvy.
  • 1530s - Jacques Cartier, who explored the St.
    Lawrence River in Canada, lost sailors to scurvy
    until the local Indians explained how the use of
    a tea made from birch bark cured the disease.
  • Chemical and Engineering News, Indians in Canada
    used birch bark tea for scurvy, Chemical and
    Engineering News, February 19, 1991, p. 56.

Ascorbic Acid History-3
  • Scurvy became the worst of the occupational
    illnesses because approximately 2,000,000 million
    sailors died from the disease over the next 300
  • Large numbers of African slaves also died during
    transport from Africa to the Americas.
  • 1747
  • Dr. James Lind, a British naval surgeon, reported
    on an experiment where he tried various
    treatments for scurvy while aboard a ship.
  • These ranged from oranges and lemons, to drinking
    seawater daily, to using vinegar with each meal.
  • Only the patients on oranges and lemons improved.

Ascorbic Acid History-4
  • Forty years later the British Navy finally began
    issuing 0.75 oz of lime or orange juice per day
    to the sailors. The East India Company also
    followed this procedure.
  • By the 1850s, most commercial sailing vessels
    used steam.
  • The result was faster trips and fresher food for
    the crew. Scurvy ceased to be a problem among
  • Dr. Lind was a very dedicated and intelligent
    naval surgeon.
  • He recommended shipboard delousing methods like
    those used today to combat typhus, suggested the
    use of hospital ships for sick sailors in
    tropical ports, and in 1761 arranged for
    shipboard production of drinking water by

Ascorbic Acid History-5
  • Scurvy on land - This was seen in convicts, the
    California gold miners, prisoners of war, Irish
    farmers deprived of fresh potatoes (a good source
    of vitamin C) during the potato blight, Arctic
    explorers, populations in cities under long term
    siege, etc.
  • Barlow's Disease - scurvy in infants.
  • It resembles adult scurvy except that infants
    don't have any teeth to lose.
  • It was common in during the late-Victorian
    periods and affluent London and New York mothers
    bottle-fed their infants. The product was
    acceptable except for its lack of Vitamin C.
  • Breast-fed infants generally do not get scurvy
    because the maternal milk can contain up to seven
    times the ascorbic acid concentration of maternal
    blood plasma.
  • Because of this fact, scurvy was not seen in
    infants in czarist Russia even though it was
    endemic among the adult peasant population.
  • Scurvy became a disease among the affluent in the
    late 19th century particularly due to the
    pasteurization of milk used in infant formula.

Ascorbic Acid History-6
  • 1907
  • A paper was published by two researchers who were
    investigating beriberi reported that guinea pigs
    fed solely on grain developed scurvy.
  • This was the first report of an animal model for
    this nutritional disorder.
  • 1932
  • Ascorbic acid was isolated

Ascorbic Acid Chemistry
  • In theory, either the reduced or oxidized form of
    the vitamin is effective.
  • In practice, the oxidized vitamin C is very
    unstable with hydrolysis of the lactone ring the
    site of degradation.
  • This is why vitamin C activity can decrease in a
    pitcher of orange juice over time, particularly
    at room temperature.
  • The D-isomer has no vitamin activity, but it can
    be used as an antioxidant in foods.

Ascorbic Acid Chemistry-2
Why Is Ascorbate Essential?
  • Ascorbic acid is not a vitamin in most animals.
  • It is synthesized from glucose.
  • Humans, other primates and guinea pigs lack the
    ability to make L-gulonlactone and then oxidize
    it to ascorbic acid.
  • Why would humans not have this enzyme?

Ascorbic Acid Biosynthesis
Ascorbate Uptake and Metabolism
  • Surprisingly, little is know about the details of
    the uptake and distribution of this vitamin.
  • Little is known about its pharmacokinetics.
  • Little is known about its storage.

Biochemical Functions
  • The vitamin is required for many reactions
    involving oxidations. These include
  • Tyrosine metabolism (phe ? tyr)
  • Formation of hydroxyproline from proline
  • Formation of hydroxylysine from lysine
  • Synthesis of carnitine (required for fatty acid
  • Reduction of folic acid to tetrahydrofolate
  • Antioxidant in the tissues. (protect vitamin A
    reduce C-reactive protein levels indicating
    anti-inflammatory properties.)
  • Hydroxylation of steroids in the adrenal gland
    forming hydrocortisone and cortisone.
  • Formation of bile acids from cholesterol.

Ascorbic Acid Deficiency
  • Scurvy (anti-scorbutic vitamin) and Barlows
  • Scurvy is a degeneration of the connective
    tissues probably related to the inability to form
    the hydroxylated amino acids seen in cartilage,
    elastin and other related proteins.
  • The result is the hemorrhaging, loss of teeth,
    improper bone growth, etc.

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Antioxidant Role of Vitamin C
  • The DRIs are based on prevention of scurvy.
  • Vitamin C also is a water-soluble antioxidant.
  • Should humans take larger amounts of ascorbate to
    prevent or reduce the severity of
  • Common cold?
  • Malignancies?
  • Diabetes mellitus
  • Cardiovascular disease.
  • The results are mixed.
  • The vitamin, along with lipid-soluble vitamin E,
    appears to be beneficial in smokers.
  • Vitamins C and E do not reduce the risk of
    preeclampsia hypertension and proteinuria during
    pregnancy, the risk of intrauterine growth
    restrictions or the risk of death or other
    serious outcomes in their infants.

Hypervitaminosis C-1
  • This appears to be a very safe vitamin as
    evidenced by individuals take megadoses for a
    variety of anecdotal reasons.
  • When vitamin C became popular after Linus
    Paulings book advocating megadosing of the
    vitamin, early manufacturing was sloppy producing
    products high in sodium.
  • This led to the FDA requiring manufacturers to
    list the sodium content on the label.
  • This led the manufacturers to clean up their

Hypervitaminosis C-2
  • There have been some problems seen when people
    suddenly reduce their intake from the megadoses
    to the levels of its RDA.
  • The patient's metabolism is geared up to
    eliminating the large amounts of excess vitamin.
    Sudden cessation of vitamin intake might cause a
    transient deficiency. (Anecdotal)
  • This may be most serious in infants. Babies born
    from mothers who have been taking large doses of
    Vitamin C can show clinical signs of scurvy
    because they are capable of metabolizing the
    large doses that crossed the placental barrier.
  • These children may have to be withdrawn from the
    vitamin over a period of time. (Anecdotal)

Ascorbic Acid Dosage Forms-1
  • Most of the vitamin is made synthetically from
    glucose to maintain stereochemistry.
  • Does that mean that synthetic ascorbic acid is
  • There is a big market for the vitamin.
  • Takeda U.S.A. has a 90 million Vitamin C plant
    in Wilmington, NC which has the capacity to
    produce 11 million lb per year.
  • A plant formerly owned by Roche can produce 30
    million lb per year.

Ascorbic Acid Dosage Forms-2The sodium salt is
usually used for the parenteral dosage forms.The
palmitic acid ester is found in oral dosage forms
and oil-based dosage forms.
Ascorbic Acid DRIs-1
  • AI
  • Infants 40 - 50 mg/day
  • EAR
  • Children (1 - 8 years) 13 - 22 mg/day
  • Boys (9 - 18 years) 39 - 63 mg/day
  • Girls (9 - 18 years) 39 - 56 mg/day
  • Men (19 - 70 years) 75 mg/day
  • Women (19 - 70) 60 mg/day
  • Pregnancy 66 - 70 mg/day
  • Lactation 96 - 100 mg/day

Ascorbic Acid DRIs-2
  • RDA
  • Children (1 - 8 years) 15 - 25 mg/day
  • Boys (9 - 18 years) 45 - 75 mg/day
  • Girls (9 - 18 years) 45 - 65 mg/day
  • Men (19 - 70 years) 90 mg/day
  • Women (19 - 70) 75 mg/day
  • Pregnancy 80 - 85 mg/day
  • Lactation 115 - 120 mg/day

Ascorbic Acid DRIs-3
  • UL
  • Infants Not established
  • use formula and food only
  • Children (1 - 8 years) 400 - 650 mg/day
  • Boys Girls (9 - 13 years) 1,200 mg/day
  • Adolescents (14 - 18 years) 1,800 mg/day
  • Pregnancy 1,800 - 2,000 mg/day
  • Lactation 1,800 - 2,000 mg/day
  • Adults (19 years) 2,000 mg

Food Sources
  • Citrus fruits
  • Berries
  • Broccoli
  • Green cabbage
  • Potatoes