Solutions

Question 1

Solutions

Answer 1

• Liquid preparations with one or more substances dissolved in a suitable solvent(s)
• Can be oral, topical, optic, ophthalmic, injections

Different than suspensions which are solid particles SUSPENDED in liquid, not dissolved.

Question 2

Solution Advantages

Answer 2

1. Faster onset of action
2. Dose uniformity
3. Easier to swallow
4. Reduces stomach irritation
5. More variability with dose strengths

Question 3

Solution Disadvantages

Answer 3

1. More likely to take the incorrect dose
2. Taste
3. Messier than tablet
4. Bulky to stores
5. StabilityAcc

Question 4

Solubility Clinical Relevance

Answer 4

• Solubility affects bioavailability and therapeutic response
• Need enough drug in solutions to reach therapeutically meaningful concentrations (related to the drugs solubility and permeability)
• Stability of drug is also connected to its solubility

Question 5

Dissolution

Answer 5

The process of the solute dissolving in the solvent, which could take a significant amount of time depending on the conditions.

Solubility is a property of the solute that describes how far the solute would dissolve into a solvent

Question 6

Biopharmaceutics Classification System (BCS)

Answer 6

• Class 1 = highly soluble and permeable (Ex. Diltiazem)
• Class 2 = high permeability but low solubility (Ex. Nifedipine)
• Class 3 = low permeability but high solubility (Ex. Insulin)
• Class 4 = low permeability and solubility (Ex. Taxol)

Question 7

Solubility

Answer 7

• spontaneous interaction of 2+ substances to form homogeneous molecular dispersion
• [] of solute in saturated solution at a specific temperature

Question 8

Saturated Solution

Answer 8

No more solute can be dissolved in solvent

Question 9

Un-/sub-saturated Solution

Answer 9

Dissolved solute is below the saturated concentration (can add more solute)

Question 10

Supersaturated Solution

Answer 10

Contain more solute than it would normally contain, usually manipulated with temperature or pressure to achieve.

Question 11

Expressing Solubility

Answer 11

-# mLs or solvent in which 1 gram of solute will dissolve
-Molality (moles/kg of solvent)
-Molarity (moles/L of Solution)
Percentages (w/w, w/v, v/v)

Question 12

Relative Solubility Terms

Question 13

Types of Solutions

Answer 13

1. Aqueous
2. Syrups - aqueous solutions containing sugar
3. Elixirs - sweetened hydroalcoholic solutions
4. Aromatic Waters - aromatic materials in aqueous solvent
5. Tinctures/Fluidextracts - extract active from crude drug, usually contains ethanol

Question 14

Aqueous Solvent Types

Answer 14

1. Purified water - less impurities; purified by distillation, ion exchange, or reverse osmosis
2. Ethyl alcohol
3. Rubbing alcohol - topicals
4. Glycerin - clear, sweet, viscous
5. Propylene glycol - viscous

Question 15

Non-aqueous Solvents

Answer 15

• Fixed oils of vegetable origin (non-water miscible)
• Better for external applications
• Wide manufacturing processing
• Limited for parenterals (olive, sesame, maize, cottonseed, castor oil)

must consider cost, flammability, stability, comparability, and toxicity

Question 16

Excipients

Answer 16

• Preservatives: prevent microbial growth
• Flavors/colors: increase palatability
• Stabilizers: maintain API stability
• Antioxidant
• Isotonicity modifiers
• Viscosity enhancements
• Cosolvents