DIFFUSION CELLS FOR IN-VITRO AND EX-VIVO PERMEATION STUDIES OF DRUGS
The present invention is a diffusion cell for in-vitro and ex-vivo permeability studies of drugs. The permeation cell is a device for studying the permeation and/or diffusion of substances, in particular pharmaceuticals, through selective membranes such as synthetic or biological membranes (mucosas and tissues). The cell is designed for working in vertical or horizontal manner
The permeation cell, both horizontal and vertical type, is substantially constituted by two hollow bodies called donor (5) and acceptor (1) compartments. The two compartments are separated from each other by a membrane-support disc (3) perforated in the middle on which membrane (4) is resting. Synthetic or biological membranes (mucosas and tissues) can be used. The support disc is interchangeable in order to change the permeation surface in a range between 1 to 10 cm2 with regard to the experimental requirements. The donor compartment can be closed by a lid (6). The acceptor compartment (1) has two opposed holes for the inlet and the outlet of acceptor liquid with a perfect hydraulic or hydrodynamic seal. The cell is designed for working in vertical or horizontal manner.
Although the cells available are suitable for the purpose, they show several drawbacks that affect the reproducibility of data and adaptability mainly due to:
- formation of air bubbles under membrane surface, especially during sampling and replacing of the acceptor fluid;
- difficulty of loading the powder and/or semi-solid samples;
- fixed permeation area.
The invention overcomes these problems as:
- it avoids the formation of air bubbles under the permeation surface generating highly reproducible data;
b. it allows a quick assembly and easy change of the diffusion surface and thus it is suitable for testing liquids, semisolids and solids.
- Pharmaceutical (R&D, bioequivalence studies);
- Biomedical (ionophoresis studies and dialysis);
- Material for packaging;
- Versatility of use (horizontal, vertical, static, dynamic);
- Adaptability for studying solid, liquid and gaseous substances;
- Flexibility (same shape, different permeation surface and volume);
- Reproducibility of data;
- Economy (simple materials and construction process, maintenance.