Drug Formulation And Absorption

Question 1

Formulation is the process?

Answer 1

In which different chemical substances, including the active drug, are combined to produce a final medicinal product

Question 2

Active ingredient is?

Answer 2

Any component of a drug product intended to furnish pharmacological activity

Question 3

2 examples of how drug formulation and absorption are linked

Answer 3

Heparin and low Molecular weight heparin
Immediate and modified release morphine

Question 4

Describe heparin vs low molecular weight heparin

Answer 4

Heparin= naturally occurring molecule
Low molecular weight heparin is a shorter molecule produced by fractionation of heparin
= physio-chemical difference - 2 different active ingredients

Question 5

Immediate vs modified release morphine

Answer 5

Active ingredient (morphine) is identical to immediate release
In controlled release preparations morphine is absorbed e.g. Onto hydrophilic polymer
This is a modification information to alter the rate of absorption

Question 6

Drugs may move across phospholipid bilayer how?
in terms of transport

Answer 6

Active transport
Facilitative transport
Pinocytosis
Passive diffusion

Question 7

Weak acids are proton donators or acceptors?

Answer 7

Proton donators

Question 8

Weak bases are proton donators or acceptors?

Answer 8

Proton acceptors

Question 9

For a weak acid, if the ph is below its pka will more of the molecule be ionised or unionised?

Answer 9

Unionised

Question 10

For a weak base if the ph is below the pka, will move of the molecule be ionised or unionised?

Answer 10

Ionised

Question 11

pka is?

Answer 11

The pH at which ionised and unionised concentrations are equal

Question 12

Log 1=

Answer 12

O

Question 13

Ka =
equation

Answer 13

(Proton acceptor) (H+) / proton donator

Question 14

pH=
equation

Answer 14

Log( proton acceptor) / (proton donor) + pKa

Question 15

Excipients

Answer 15

Everything else in the product that isn’t the active molecule

Question 16

Example of excipients

Answer 16

Anti-adherents
Binders
Coating
Coloring, flavours and sweeteners
Disintegrates
Emulgents
Preservatives/antioxidants/buffers

Question 17

Pathway of aspirin after being dissolved in the stomach

Answer 17

Some aspirin is absorbed by the stomach and enters the hepatic portal vein
Most of the aspirin will be absorbed by the small intestine
Aspirin will undergo first-pass metabolism in the liver
Eventually reaches systemic circulation

Question 18

example of drug formulation affecting absorption

Answer 18

Modified release
Enteric coating

Question 19

Modified release is designed to?

Answer 19

Deliver drug over a continuos period or delay absorption

Question 20

Enteric coating

Answer 20

Coating that prevents dissolution, disintegration in the stomach

Question 21

Why might enteric coating delay release of drug to a specific area of GI tract to?

Answer 21

Prevent breakdown of drug in low pH of stomach
Deliver drug to specific site of action
Minimise adverse effects from direct gastric irritation

Question 22

Example of drug formulated by enteric coating

Answer 22

Omeprazole

Question 23

Example of drug formulated to modified release

Answer 23

Morphine or isosorbide mononitrate

Question 24

Example of Drug delivery systems

Answer 24

Buccal wafers
Solid gels can be implanted for slow and prolonged release (contraceptive)
Patches
Ointments

Question 25

Example of patches

Answer 25

Fentanyl

Question 26

Example of ointment

Answer 26

Chloramphenicol eye ointment

Question 27

Example of solid gel implant for slow and prolonged release

Answer 27

Contraceptive

Question 28

Example of buccal wafers

Answer 28

Ondansteron - dissolve in mouth

Question 29

Method example of modified release

Answer 29

Drug in a gel matrix that swells on contact with water

Question 30

pH for acid:

Answer 30

= pKa + log ( (A-) / (AH) )

Question 31

pH for a base

Answer 31

= pKa + log ( (B) / (BH+) )

Question 32

For a weak acid, if the pH is below its pKa then more of the molecule will be unionized/ ionised?

Answer 32

unioised

Question 33

For a weak base, if the pH is below its pKa then more of the molecule will be unionized/ ionised?

Answer 33

ionised