Dissolution and disintegration
The effectiveness of an oral dosage form depends upon the ability of a drug to dissolve in fluids of the gastrointestinal tract. Dissolution is an in-vitro test that evaluates how an active pharmaceutical ingredient is extracted from a solid dosage form. Tablet disintegration is the process of breaking up a dosage form in smaller particles to increase the available surface area. It is important as tablet disintegration could determine drug availability for dissolution, and subsequently absorption.
When problems in dissolution are observed, it is important to evaluate if disintegration or solution speed is the limiting factor.
When disintegration is the limiting factor, dissolution can be improved by a reduction of the disintegration time, generally driven by the disintegrant.
- Increase amount of disintegrant
- Add Pharmacel® to aid disintegration of lactose based formulations
- Optimise type of disintegrant
- SuperTab® 30GR is the quickest disintegrating DC lactose grade
- Decrease compaction to reduce hardness
When the disintegration is not limiting the dissolution, the dissolution can be improved by adjustment of the API properties to improve solubility of API.
- Increase surface of API
- Modify surface properties of API
- Add solubiliser
- In some cases it might help to intimately mix API with excipient with high solubility and high adhesion to API to aid dissolution
- Make solid dispersions with Primojel®