MCMP 824: Lecture 2 Flashcards
when we look at lipophilicity of a drug molecule and how that affects its effectiveness in a biological system, we observe this _____ relationship
parabolic
when you reach an optimal Log P, this drug has ____ ____ required to cause a _____ ____
- minimum dosage
- biological effect
ability to pass through membranes will be based on the
optimal lipophilicity AKA Log P
if a drug molecule is too ______ it will not enter the membrane at all
hydrophilic (lipophobic)
if a drug molecule is too _____ they get stuck within the membrane within the lipid bilayer
hydrophobic (lipophilic)
Often times we don’t go through the trouble of measuring Log P. We instead use?
- calculate Log P (C logP)
often times we don’t go through the trouble of measure Log P. We instead use calculated logP (C LogP) and ____ ____
pi values
Pi values =
hydrophobic substituent constant
a drug molecule can be broken down into fragments, and the overall calculated log P (C logP) is a ____ of ____ ____ of the molecules fragments
- sum of pi values
pi values can be determined by _____ appropriated ___ ____ _____
- subtracting
- log P values
the solubility of drugs usually ____ with the number of hydrogen bonds increases because?
- increases
- like dissolves like
the water solubility of organic molecules generally increases with an increasing number of 1) ___ ____ and 2) ____ ____ _____
- hydrogen bonds
- ion-dipole interactions
water is very polar so more dipole molecules or a carbonyl then can?
easily solvate those molecules
soluble drugs consist of highly ____ _____ formed from: (3)
- dissociable salts
1) strong acids and strong bases
2) strong acids and weak bases
3) weak acids and strong bases
often we have drug molecules that consist of soluble salts and they are generally formed with
strong acids and strong bases
different salt forms can have different _______ : critical information of drugs and how they can have different properties
- solubilities
the ionization state of a drug has an impact on the drug’s? (3)
1) site of absorption
2) extent of absorption (bioavailability)
3) activity at its receptor
the Henderson-Hasselbach equation allows one to calculate?
the degree of ionization of a drug molecule at a specific pH
which form do we want the drug to be in to be absorbed best?
UNIONIZED
what is wrong with Log P?
doesn’t really take into effect whether a molecule is ionized or not
so what will take into account whether a molecule is ionized or not?
Log D
if a drug is an acid or base and is partitioned between two phases, and:
(1 + 2)
then the partition coefficient (P) should be converted to D or “effective Log P”
1) both the drug and its conjugate form are soluble in phase 1 (aqueous)
2) only the drug in in its uncharged form is soluble in phase 2 (organic)
most drugs are absorbed in the ______ where the pH is between ?
- jejunum
- 5-7
however, an acidic drug will tend to be absorbed in the ____ where the pH is generally ?
- stomach
- 1-3
