@ sarim Help with PKA / PH concept - zen786

[ArchivalUser]

Now say like if the Drug is "ACIDIC", what will happen to it if we place that drug into a "BASIC Medium"?

Will it become Ionized (Dissociate) or become Non-ionized (Non-dissociate) ?

[ArchivalUser]

it will be ionized and get excreted ??

[ArchivalUser]

great. yes.

OK say like if the "An Acidic Drug" which has it's own pka = 3.5

it means if we place this drug into a "Medium with pH of 3.5" , the will be

50%----- Ionized (dissociated/non-pronated)
50%-----Non-ionized(Non-dissociated/ pronated)

Now if start to raise the Medium pH (making it Alkaline/Basic) what will happen to that drug?

More of it will become Ionized or Non-ionized?

[ArchivalUser]

if a drug has pka of 3.5 and we start to raise the mediums pH making it basic the drug will become ionized... because drugs get absorbed better in their pH environment ?


i dont understand what is the difference between pH and pKa why two terms ??

[ArchivalUser]

say like if a "Medium pH" ranging from (2 to 13)

2 -----------------*---------- 13

* that u see is the Medium pH ( e.g 8.5) at which a "Specif drug" is 50% in Ionized form and 50% Non-ionized form.... this Medium pH of 8.5 is said to be that drug pka.

[ArchivalUser]

ohhhhhhhhhhhhhhhhhhhhhhhhh okay gotcha

ok so if aspirin is at 1.5 pH and the mediums pKa is also 1.5 would that make aspirin 50% ionized and 50% unionized or 100% unionized ?

[ArchivalUser]

pka is the point of reference, if the medium pH is raised above it or declined below it, will affect the dissociation of the drug "Depending on if the drug is ACIDIC or BASIC"

-I'll join u after my meal.

[ArchivalUser]

okay thank you enjoy !!

[ArchivalUser]

Every drug has it's own "Specific pka" (Aspirin pka = 3.5)

if a "Drug X" has it's pka= 1.5

Then this Drug X at the medium pH of 1.5 , will be in 50% ionized and 50% non-ionized.

[ArchivalUser]

which means half of it will get absorbed and cross cell membrane and the other half will get excreted ?