IPS1: Dispensing - Part 4 - Physical Incompatibilities

Incompatibility

Conflict, disagreement, differences in prescription;

Problem which could arise during the compounding or dispensing of a prescription; and

Interaction of two or more substances

A

Incompatibility is unintentional, but some are intentional or expected

a. True

b. False

Physical

Chemical

In vitro incompatibilities

Therapeutic

In vivo incompatibilities

Physical incompatibility

physical or chemical interaction between two or more ingredients that leads to a visibly recognizable change

Manifestations of Physical Incompatibility

1. Incomplete solution

2. Precipitation

3. Liquefaction of solid ingredient

4. Vaporization

5. Polymorphism

6. Water loss

Incomplete solution

Insolubility or immiscibility

Insolubility

inability of the solid material to dissolve in a particular solvent system

D

Manifest insolubility

a. Camphor + Water

b. Gum + Alcohol

c. Iodine + Water

d. all of these

Immiscibility

two or more liquids fail to mix with one another homogeneously.

C

Manifest immiscibility except

a. Cod liver oil + water

b. 1mL phenol + 10 mL water

c. Iodine + water

d. none

Precipitation

the solute which is originally dissolved in the solvent is thrown out of solution

separation of the solute

C

Reasons for precipitations

I. Salting out

II. Change in volume

III. Change in solvent system

IV. Change in temperature

V. Change in pH

a. I, II

b. I, II, III, IV, V

c. I, III, IV, V

d. I only

Salting out

concentrated solutions of electrolytes are mixed in prescription with solutions of non-electrolytes; electrolytes and non-electrolytes compete for the water molecules.

A

Which of the following precipitate because of salting out?

a. KBr + Camphor water

b. NH4Cl + Camphor + Alcohol + Water

c. NH4Cl + Water

d. Phenobarbital Na + Syrup of Orange

B

Precipitate because of change in solvent system

a. KBr + Camphor water

b. NH4Cl + Camphor + Alcohol + Water

c. NH4Cl + Water

d. Phenobarbital Na + Syrup of Orange

Change in temperature

Exothermic

Endothermic

Endothermic reaction

absorbs heat from the surrounding; increase the temperature of the solution

C

Manifest exothermic reaction

a. KBr + Camphor water

b. NH4Cl + Camphor + Alcohol + Water

c. NH4Cl + Water

d. Phenobarbital Na + Syrup of Orange

Exothermic reaction

gives off heat to the surrounding

decrease temperature of the solution

decrease solubility, with the exception of lime water

A

Which is more soluble in cold water than in hot water

a. Lime water

b. Camphor

c. NH4Cl

d. KBr

D

Manifest precipitation due to change in pH

I. KBr + Camphor water

II. Codeine SO4 + NaOH

III. Phenobarbital Na + Syrup of Orange

a. I only

b. II only

c. I, II, III

d. II, III

Liquefaction

due to deliquescence, hygroscopisity, efflorescence and eutexia

Deliquescence

absorbs moisture and dissolved

absorption moisture to form water of hydration leading to gradual dissolution and liquefaction

A

Example of deliquescent material

a. NaCl

b. KBr

c. SO4

d. Alum

Efflorescence

release water of crystallization

C

Efflorescent substances

I. Citric acid

II. Atropine SO4,

III. FeSO4

IV. Alum

V. Effervescent tablet

a. I, II, III

b. I, II, III, IV

c. I, II, III, IV, V

d. II, III, IV

Eutexia

liquefaction of solids at room temperature, due to the lowering of their melting points

A

ASA, menthol, phenol, thymol, camphor, salol, and other aldehydes and ketones are what type of substance?

a. Eutectic

b. Efflorescent

c. Hygroscopic

d. Deliquescent

C

Exhibit eutexia

a. KBr + Camphor water

b. NH4Cl + Camphor + Alcohol + Water

c. Lidocaine + Prilocaine → EMLA

d. Phenobarbital Na + Syrup of Orange

B

Proportion of Salol:Acetanilide that will liquefy

a. 1:2

b. 2:1

A

Proportion of Salol:Acetanilide that will not liquefy

a. 1:2

b. 2:1

A

Proportion of Salol:Magnesium carbonate that will not liquefy

a. 1:2

b. 2:1

B

Proportion of Salol:Magnesium carbonate that will liquefy

a. 1:2

b. 2:1

Hygroscopic

Absorbs moisture but does not dissolve

C

Hygroscopic substance

a. sugar

b. silica gel

c. a and b

d. none

Vaporization

also known as volatilization; liberation of the active ingredients

B

Volatile oils, ketone, esters, NTG, aldehyde, alcohol may under go

a. polymorphism

b. volatilization

c. efflorescence

d. evaporation

Polymorphism

existence of one or more physical state or and/or amorphous/crystalline form

Cocoa butter

Chloramphenicol

Substance that can undergo polymorphism

B

Stable form of cocoa butter

a. alpa

b. beta

B

The only therapeutically significant form of chloramphenicol

a. A

b. B

c. C

Water loss

manifested by liquid dosage forms; reverse of hydration

cause an increase in the potency or concentration

D

Water loss

a. emulsion phase inversion (into W/O emulsion)

b. crumbling of ointments

c. syneresis of gel

d. all of these