Question

2.19. During the early part of the 20th century, sulfanilamide (an al drug g) was only company decided to market a liquid formulation of the drug. Since sulfanilamide was known to be highly insoluble in water and other common pharmaceutical solvents, a number of alternative solvents were tested and the drug was found to be soluble in diethylene glycol (DEG). After satisfactory results were ppearance, and fragrance, 240 gallons of sulfanilamide in DEG were administered by injection or in a solid pill. In 1937, a pharmaceutical obtained in tests of flavor, manufactured and marketed as Elixir Sulfanilamide. After a number of deaths were have been caused by the formulation, the Food and Drug Administration (FDA) mounted a campaign to recall the drug and recovered about 232 gallons. By this time. 107 people had died. The incident led to passage of the 1938 Federal Food, Drug, and Cosmetic Act that significantly tightened FDA safety requirements. Not all of the quantities needed in solving the following problems can be found in the text. Give sources of such information and list all assumptions (a) The dosage instructions for the elixir were to "take 2 to 3 teaspoons in water every four hours. Assume each teaspoon was pure DEG, and estimate the volume (mL)of DEG a patient would have consumed in a day (b) The lethal oral dose of diethylene glycol has been estimated to be 1.4mL DEGkg body mass Determine the maximum patient mass (lb.) for which the daily dose estimated in Part (a) would be Adapted from Suephanie Farrell, Mariano J. Savelski, and C. Stewart Slater, "Integrating Pharmaceutical Concepts into Introductory Chemical Engineering Courses-Part 1" (2010), http://pharmahub.org/resources/360.

Answer 1

(a) The dosage instruction for the elixir were to "take 2 to 3 teaspoons in water every four hours" Assume each teaspoon was pure DEG, and estimate the volume (ml) of DEG a patient would have consumed in a day.

Answers: 1 tea spoon measure of 5 ml

number of dosages taken by patient as prescribed in 1 day = 24/4 = 6 dosages

Each dose = 10 to 15 ml (i.e equivalent to 2 to 3 tea spoons)

So volume of drug that taken by a patient in a day = 60 to 90 ml / day

(b) The lethal oral dose of Diethylene glycol(DEG) has been estimated to be 1.4 ml DEG per kg of body mass. Determine the maximum patient mass (lb_m) for which the daily dose estimated in part (a) would be fatal. If you need values of quantities you cannot find in this text, use the internet. Suggest three reasons why the dose could be dangerous to a patient whose mass is well above the calculated value.

Answer: The dose = 60 to 90 ml

So maximum patient mass for which the daily dose would be fatal

= 60 / 1.4 = 42.8 kg and 90/ 1.4 = 64.28 kg

(c) Estimate how many people would have been poisoned if the total production of the drug had been consumed.

Answer :

If the total product has been consumed and the average mass of human being = 65 kg [assume 65 kg is the avg. mass of human body as average weight is not given]

So consumption by one human = 65 X 1.4 = 91 ml

240 gallons = 3785.41 X 240 ml = 907538.4 ml ( as 240 gallons of Salfanilamide in DEG were manufactured)

Number of human that will consume the drug = 907538.4 / 91 = 9972.94 i.e. = 9973 (approx) people would have been poisoned if total production of the drug had been consumed.

(d) List steps the company should have taken that would have prevented this tragedy .

Answer:

1. The company should give the dosage value on the medicine packaging

2. There should be well awareness about the lethal effects if excess dose is taken

3. There should be good screening of the drug before commercialisation of the medicine