Lecture 4: solutions and emulsions

Question 1

Emulsions

Answer 1

two phase system consisting of at least 2 immiscible liquids
heterogenous
thermodynamically unstable
Lipid phase & Aqueous phase + emulsifier = emulsion

Question 2

When is an emulsion used?

Answer 2

when two immiscible liquids must be dispersed in the same preparation

Question 3

External phase

Answer 3

continuous phase
flavoring added to this phase

Question 4

Internal phase

Answer 4

Dispersed, discontinuous phase

Question 5

Emulsion usage: topical

Answer 5

most often topical use
-O/W = creams, apply to weeping lesions, drying effect
-W/O = lotions, lubricating effect

Question 6

Emulsions usage: oral

Answer 6

can mask poor taste
improve absorption of some drugs

Question 7

Emulsions usage - IV

Answer 7

Used to administer calories

Question 8

Emulsification

Answer 8

addition of energy through trituration or homogenization, creating small droplets of one liquid phase within another and static charge around those droplets

Question 9

Emulsification Methods

Answer 9

1. English (wet gum)
2. Continental (dry gum)
3. Bottle (shaking)
4. Beaker (heating)

Question 10

Emulsion complexities

Answer 10

1. preservatives –> aqueous phase in the free, unbound, unadorbed, unionized state
2. antioxidants –> prevent lipid rancidification
3. Flavoring –> external phase (continuous)

Question 11

Solutions

Answer 11

liquid preps that contain one or more chemical solutes dissolved in a suitable solvent or mixture of mutually miscible solvents
- homogenous

Question 12

solute

Answer 12

present in smaller amount
may include:
- active drug
- flavoring/coloring
- preservatives
- stabilizers
- buffering salts

Question 13

Solvent

Answer 13

present in larger amount, liquid
- water
- ethanol
- glycerin
- propylene glycol
- isopropyl alcohol

Question 14

saturated solution

Answer 14

contains the max amount of solute that the solvent can accommodate

Question 15

Supersaturated solution

Answer 15

larger amount of solute than the solvent can normally accommodate
typically prepared at a higher temperature

Question 16

Types of solutions

Answer 16

1. aqueous solutions
2. non-aqueous solutions

Question 17

Aqueous solutions

Answer 17

drug dissolved in water
most common form of oral solution
can add any flavorings/preservatives/buffering salts
DI or purified water must be used
Ex: syrups, aromatic waters, mucilage, aqueous acids

Question 18

nonaqueous solutions

Answer 18

contains solvent other than water
+/- water
most commonly alcohol
ex: elidirs, spirits, tincutres

Question 19

Cautioned use of nonaqeuous solution in which population?

Answer 19

pediatrics

due to alcohol content

Question 20

Solution administration routes

Answer 20

nonsterile: oral, topical, otic
Sterile: nassal, inhalations, irrigations, injections

Question 21

Advnatages of solutions

Answer 21

completely homogenous
drug disperse immediately available for absorption (already dissolved)

Question 22

Solution disadvantages

Answer 22

drug less stable in solution than dry solid form
not all drugs soluble in accepted pharmaceutical solvents

Question 23

Units of measure of solutions

Answer 23

1. Concentration
2. molarity
3. percent
4. ratio strength

Question 24

Concentration

Answer 24

mg/mL, g/mL

Question 25

Percent

Answer 25

%w/v (g/100mL) %v/w (ml/100g) mg% = mg/100mL etc

Question 26

Ratio Strength

Answer 26

X:Y X grams of solute for every Y mL solution

Question 27

Solution compounding

Answer 27

1. weigh out active ingredient, transfer to beaker 2. dissolve drug in minimal amount of distilled water. swirl to mix until completely dissolved 3. quantitatively transfer dissolved drug to a 250 mL graduated cylinder, using repeated washings of syrup 4. QS the graduate to 118.3 mL with cherry syrup and mix by pouring between the dispensing container and the graduated cylinder 5. transfer solution to a 4 oz dispensing container and cap securely 6. label product and dispense w/ appropriate measuring device

Question 28

1 oz to mL

Answer 28

29.57 mL

Question 29

1 oz to grams

Answer 29

28.35 g

Question 30

10% solution contains how many grams of drug?

Answer 30

10g per 100 mL