17 Questions
What is the main purpose of a solid dispersion in pharmaceuticals?
To alter the solubility and solution rate of the drug
In a solid dispersion, what happens to the physical state of the drug particles?
They change from a crystalline state to an amorphous state
Why is obtaining the correct polymorph or hydrate of a pharmaceutical substance important?
It can affect solubility and bioavailability
What happens when a solid dispersion is added to water?
The solid carrier dissolves, leaving the drug dispersed as fine particles
How does solid dispersion aid in drug dissolution without chemical modification of the drug?
By molecularly dispersing the drug in a solid solvent
What is the significance of the contact angle (θ) in determining wetting of powders?
Contact angles less than 90° indicate good wetting, while angles greater than 90° suggest problems with wetting.
How does the presence of hydrophobic drugs impact the wetting and solubility of solid drugs?
Hydrophobic drugs are not readily wetted and have low solubility.
What role do surfactants play in improving wettability of powders?
Surfactants enhance wettability by decreasing the contact angle.
What does a contact angle of 0° signify in terms of wetting?
Complete wetting
How is solubility defined in relation to a drug and a solvent?
Solubility is the maximum quantity of drug dissolved in a given volume of a solvent solution.
How does solubility impact the bioavailability of a drug?
Higher solubility usually results in increased bioavailability.
How does particle size reduction impact drug dissolution?
Increases drug dissolution by increasing exposure of the drug surface to the solvent
In what scenario would dissolution be the rate-limiting step in drug absorption?
When drug dissolution is slow due to physicochemical properties or formulation factors
What role does particle size reduction play in the transport of substances across the intestinal wall?
Facilitates transport by increasing exposure of particles to the solvent
How do very small particles in the nanometer range impact absorption into the systemic circulation?
Enhance absorption by facilitating transportation through enterocytes
What happens to drug bioavailability if dissolution is the rate-limiting step in absorption?
Bioavailability decreases
Why is the particle size of a drug considered important?
To increase dissolution by increasing exposure of the drug surface to the solvent
Explore how particle size reduction can affect polymorphs, solubility, and ultimately bioavailability in drug absorption. Understand the impact of slow drug dissolution on absorption and bioavailability due to physicochemical properties and formulation factors.
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