Study Set Content:
This includes:
The chemical nature of the drug
Particle size and surface are of the drug
c) Type of dosage forms
The excipients and processes used in the manufacturing
of the drug delivery system
Having different pH could affect the journey of a drug
because of the
the basic and acidic components of a drug.
Basic and acidic functional group will undergo
dissociation.
Presence of food in the stomach can greatly affect the
gastric emptying time.
From high to low concentration and do not require
energy.
PASSIVE DIFFUSION
The usual requirement for active transport is(blank)between the drug and the substrate normally
transported across the membrane.
STRUCTURAL
SIMILARITIES
ways:
1. Transport of the drug occurs against a
concentration
gradient
Transport mechanism can become (blank) at high drug
concentration
saturated
A specificity for a certain molecular structure can promote
(blank) in the presence of a similarly structured
compound
competition
The absorption of small molecules ( molecular radii less
than 4 A) through water-filled pored of biologic
membrane
CONVECTIVE ABSORPTION
From low to high; requires energy and carrier.
Active transport
In every wave of electrons, definitely positive charges
can cross.
ION PAIR ABSORPTION
Requires size.
CONVECTIVE ABSORPTION
The pH- partition hypothesis on drug absorption
a) The gastrointestinal and other biologic
membranes act like
lipid barriers
of the acidic of basic drug is
preferentially absorbed.
un-ionized form
Most drugs are absorbed by
passive diffusion
The rate of drug absorption and amount of drug
absorbed are related to the drug’s
oil-water
partition coefficient
Weak acidic and neutral drugs are absorbed from
the stomach, but (blank) are not.
basic drugs
The fraction of the drug existing in its un-ionized form in
a solution is a function of both the
the dissociation constant of
a drug and the pH of the solution at the absorption site.
If the degree of ionization is very high; it will be
easily excreted
