Preformulation of Solid Dosage Forms Flashcards
(35 cards)
What is the aim of a dosage form?
To facilitate the delivery of Therapeutic Drugs
What is a preformulation?
The first step in the ‘rational approach’ to developing a drug into a medicine
What must a dosage form be?
Safe
Efficient
Reproducible
Convenient
What does In-vivo mean?
In a living organism
What does In-vitro mean?
In a lab environment
What is a preformulation exercise?
generates mathematical and statistical data, that helps the development of a dosage form.
What is the aim of a preformulation exercise?
To create a mathematical model for drug behaviour in the dosage form being studied.
If a drug is given by GI…
The drug MUST permeate the gut epithelium
Controlling factors of GI dosage forms
dissolution and solubility
Optimal solubility for GI dosage forms
10mg/ml
What should be done if the solubility is less than 1mg/ml
Put in a salt form
How do you determine the dissolution rate
Noyes Whitney equation
Is Solubility a Constant or a Variable
Constant
Is dissolution a constant or variable
Variable
What affects dissolution rate?
diffusion layers
concentration of drug solution
How many classes are in the Biopharmaceutical Classification?
4 Classes
Which Biopharmaceutical Class has high solubility, high permeability?
Class 1
Which Biopharmaceutical Class has high solubility low permeability?
Class 3
Which Biopharmaceutical Class has low solubility, high permeability?
Class 2
Which Biopharmaceutical Class has low solubility and low solubility
`Class 4
How are drugs with low solubility described
Brick Dust
How to fix low solubility?
Make it a Salt
Polymorph (change the structure)
Reduce the particle size
When do you convert a drug to its salt?
When it has a poor aqueous solubility
it is a weak acid
Or a weak base
The equation to find the pH of a drug?
Henderson Hasselbach Equation