Question 3 (10 marks) Nicotine patches are designed to help people stop smoking by delivering nicotine...

 

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Question 3 (10 marks) Nicotine patches are designed to help people stop smoking by delivering nicotine (C10H14N2 MW 162.2 g/mol) directly to the blood through the skin. The patches are effective for up to 16 hours and are applied to the skin each day. In one design the nicotine is dispersed in a gel that is sealed within a rectangular patch. Nicotine is released into the skin when the adhesive seal is removed from the side of the patch in contact with the skin. For a moderate smoker doctors recommend using patches that contain 14 mg of nicotine, of which 50% is normally delivered in the first 4 hours. a) Which of the following equations best describes the transfer of nicotine into the blood over 16 hours? (Assume the nicotine does not react until it passes from the blood to the brain). [1 mark] a. b. C. ac at ac at + + N AY Y + N AX ax d. (022) = 0 AZ (3NAY + 3N2Z) ac OCA+ (3NAZ) = 0 + N AZ az = 0 = 0 b) If a nicotine patch has dimensions of 4 cm long by 2 cm wide by 0.1 cm thick what is the critical dimension (in cm) for the purposes of unsteady state mass transfer [1 mark] c) What is the diffusion coefficient of nicotine in the gel (cm/s) if the long term (infinite) concentration of nicotine in a 4 cm x 2 cm x 0.1 cm patch is 1.08x106 mol/cm. Assume that the volume of the gel is equal to the volume of the patch. [2 marks] d) Doctors recommend removing this type of patch after 16 hours because the concentration of nicotine in the patch has reached the minimum effective concentration. Calculate the minimum effective concentration (mol/cm) [3 marks] e) You have been asked to redesign the patch so that the minimum effective concentration is reached at 24 hours. What is the new surface area (L x W) of the new patch such that the initial concentration is the same as the original natch? [3 marks] Question 3 (10 marks) Nicotine patches are designed to help people stop smoking by delivering nicotine (C10H14N2 MW 162.2 g/mol) directly to the blood through the skin. The patches are effective for up to 16 hours and are applied to the skin each day. In one design the nicotine is dispersed in a gel that is sealed within a rectangular patch. Nicotine is released into the skin when the adhesive seal is removed from the side of the patch in contact with the skin. For a moderate smoker doctors recommend using patches that contain 14 mg of nicotine, of which 50% is normally delivered in the first 4 hours. a) Which of the following equations best describes the transfer of nicotine into the blood over 16 hours? (Assume the nicotine does not react until it passes from the blood to the brain). [1 mark] a. b. C. ac at ac at + + N AY Y + N AX ax d. (022) = 0 AZ (3NAY + 3N2Z) ac OCA+ (3NAZ) = 0 + N AZ az = 0 = 0 b) If a nicotine patch has dimensions of 4 cm long by 2 cm wide by 0.1 cm thick what is the critical dimension (in cm) for the purposes of unsteady state mass transfer [1 mark] c) What is the diffusion coefficient of nicotine in the gel (cm/s) if the long term (infinite) concentration of nicotine in a 4 cm x 2 cm x 0.1 cm patch is 1.08x106 mol/cm. Assume that the volume of the gel is equal to the volume of the patch. [2 marks] d) Doctors recommend removing this type of patch after 16 hours because the concentration of nicotine in the patch has reached the minimum effective concentration. Calculate the minimum effective concentration (mol/cm) [3 marks] e) You have been asked to redesign the patch so that the minimum effective concentration is reached at 24 hours. What is the new surface area (L x W) of the new patch such that the initial concentration is the same as the original natch? [3 marks]

Answer rating: 100% (QA)

a The equation that best describes the transfer of nicotine into the blood over 16 hours is c CAt NAZ 0 b The critical dimension for the purposes of u... View the full answer