Page 70 - Pharmaceutics III_ 02-06-01304_Fall 2025_ Pharm D_Electronic book

• Paddle (Apparatus II).
• Basket (Apparatus I).
• Flow-through cell (Apparatus IV).
Parameters:
• Medium (pH 1.2, 4.5, 6.8).
• Temperature 37°C ± 0.5°C.
• Sampling at specific intervals.
Profiles compared using:
• f₂ similarity factor (50–100 = equivalent).

Factors Affecting Dissolution Rate:
1. Particle size and surface area.
2. Polymorphic form.
3. Solubility of drug and excipients.
4. Compression pressure.
5. Coating thickness.

Enhancement of Dissolution Rate:
• Reduce particle size (micronization).
• Use surfactants (SLS).
• Solid dispersion techniques.
• Salt formation.
• Use of hydrophilic carriers.

Biopharmaceutical Classification System (BCS):
Classifies drugs according to solubility and permeability.

Class Solubility Permeability Example

I High High Metoprolol, Propranolol

II Low High Carbamazepine, Ketoconazole

III High Low Cimetidine, Ranitidine

69