Q: Differentiate between active transport cf simple diffusion.
Ans: Differentiate between active transport & passive diffusion:
(i) It is occured against concentration gradient.
(ii) Energy is required.
(i) It occures when the concentration gradient moves from higher to lower.
i) Energy is not required.
(iii) Carrier is required. (iii) Not required.
(iv) Passive diffusion in not selective.
(iv) Active transport is selective.
-e (v) It is saturable. (v) It is unsaturable.
Q: Mention the factors that influence drug absorption.
Ans: Factors modifying drug absorption:
(i) Lipid solubility:
--> More lipid soluble drug —> more absorption
(ii) Size of the drug:
;h the —> Smaller size-* more absorption
(iii) Degree of ionization:
and it —> More ionization --> More water soluble --> Less absorption
(iv) Concentration of drug:
—> More concentration More absorption
(v) Presence of second drug: :sement Fee —>Fe"(more absorbed)
(vi) Formulation of drug:
zv —> Gaseous drug is more absorbed than liquid. And Liquid drugs are more absorbed than solid.
Q: Why some drugs are taken during meal and some drugs are taken before meal? give an example with each.
Ans: Food enhances the absorption of some drugs like riboflavin, griseofulvin, spironolactone, and propranolol. So these drugs are taken during meal.
On the contrary, food also interferes with the absorption of some drugs like ampicillin, levodopa, tetracycline. Therefore, these drugs are taken 1 hour before meal for better absorption.