The question refers to the 7 types of dissolution apparatus as defined by the United States Pharmacopeia (USP). Here they are:
| Apparatus Number | Name | Description |
|---|---|---|
| 1 | Baskets | A cylindrical basket holding the dosage form is rotated in a vessel containing the dissolution medium. |
| 2 | Paddles | A paddle stirs the dissolution medium in a vessel containing the dosage form. |
| 3 | Reciprocating Cylinder | A reciprocating cylinder moves up and down in a vessel containing the dissolution medium, immersing the dosage form. This is often used for modified-release dosage forms. |
| 4 | Flow-Through Cell | Note: This apparatus is not explicitly mentioned in the provided reference, but is a standard USP apparatus. Dissolution medium is pumped through a flow-through cell containing the dosage form. This is useful for poorly soluble drugs or suppositories. |
| 5 | Paddle Over Disk | The dosage form (usually a transdermal patch) is attached to a disk, which is then placed at the bottom of the vessel. A paddle stirs the dissolution medium above the disk. |
| 6 | Rotating Cylinder | The dosage form (usually a transdermal patch) is attached to a rotating cylinder, which is then immersed in the dissolution medium. |
| 7 | Reciprocating Disk | A reciprocating disk holds the dosage form and moves up and down in a series of vessels containing the dissolution medium. This is also utilized for transdermal systems and other specialized dosage forms. |
The choice of dissolution apparatus depends on the specific dosage form and the characteristics of the drug being tested. Understanding these apparatus is crucial for pharmaceutical scientists involved in drug development and quality control.
