Int Exam 2

Question 1

What does drug reactivity depend on?

Answer 1

Chemical reactivity, metal reactivity, light reactivity

Question 2

Why is ionization important?

Answer 2

Drugs are either acids or bases, the degree of solubility, rate of absorption, drug compatibility/interactions

Question 3

The stronger the acid, _____ the conjugate base

Answer 3

The weaker

Question 4

The greater the Ka the ____ the acid

Answer 4

Stronger

Question 5

Why is solubility important?

Answer 5

Drugs need to be solubilized to be absorbed. Some drug formulations require manipulation of solubility.

Question 6

Define solution

Answer 6

A molecular dispersion of one substance (less abundant, the solute) into another (more abundant, the solvent)

Solid dissolved into liquid is most common in pharmacies.

Question 7

Process of dissolving a solid into a liquid a liquid at the molecular level

Answer 7

1- breaking the molecular interactions b/w the solute molecules
2- breaking the molecular interactions b/w the solvent molecules makes holes for solute molecules
3- filling the solvent holes with the solute molecule to form new molecular interactions within the solute and solvent
4- diffusion of the solvated solute molecules from the solid solute into the solvent

Question 8

Dissolution

Answer 8

Is a reversible process. If a solid solute/solvent are under constant temp, pressure, pH then the dissolution rate is mostly stable. The dissolved solute molecule will be able to precipitate back to its solid state - rate is proportional to conc of the solute in solution

Question 9

How does the dissolution precipitation process reach an equilibrium?

Answer 9

This is called a saturated solution. The rate of precipitation increases as more of the solute is dissolved - this occurs until the dissolution rate and precipitation rate becomes the same

Question 10

Define solubility

Answer 10

The amount of solute per a given amount of solvent or solution when the solution is saturated

Question 11

What is the isoelectric point?

Answer 11

Is the pH at which most of the molecules are in a state carrying zero net charge.

Question 12

What is a suppository?

Answer 12

It is a semi-solid or solid dosage form containing active pharmaceutical ingredient meant to b inserted into a body orifice

Question 13

How does a suppository work?

Answer 13

It can melt at body temperature or dissolve into the aqueous secretions of the body cavity, which would release the API for absorption through the mucosa.

Question 14

Why would suppositories be used?

Answer 14

For infants - as they can’t swallow
Incapacitated patients
GI disturbances - difficulty with oral administration
Specific local action desired
To limit first-pass metabolism

Question 15

What are hydrophobic background suppository bases? (the main excipients)

Answer 15

Cocoa butter / other triglycerides

Question 16

What are hydrophilic background suppository bases?

Answer 16

Polyethylene glycols
Glycerinated gelatin

Question 17

Why do hydrophobic suppository bases have a slow release?

Answer 17

It has a slow release because it has to go through a thin aqueous layer and does not readily want to melt

Question 18

Why do hydrophilic suppository bases have a fast release?

Answer 18

It has a faster release due to it readily wanting to go into the aqueous environment