Dehydrated delivery device

Figure 2. The dehydrated delivery device produced by compression of protein and hydrophilic polymer powder.

The above procedure was also employed to investigate buccal absorption from the HEMAC experimental delivery device. As in the case of the diffusion cell the drug-loaded disc was positioned on the inner central surface of the buccal mucosa. An impermeable film coated with mucosal adhesive (F-4000, Adhesives Research, Glen Rock, PA) on the periphery was then positioned over the HEMAC disc to prevent dehydration and to secure the device in place on the mucosal surface. The disc was allowed to remain in contact with the mucosa for 4 h before it was removed for quantitation of residual drug content. Blood samples were collected over the same interval as for the saturated solution and processed in the same manner. 

Another critical consideration in protein delivery from hydrogel systems is the potential for protein denaturation in the device. For diffusion-controlled delivery systems, where water is the main transporting medium, the protein solution stability governs the type of device. Extended releasing times can be achieved with reservoir systems (Fig. 1) for highly stable proteins (Langer, 1990). Alternatively, dehydrated delivery systems... 

Price et al. (1978) developed this technique for measurement ofthe interdiffusion of poly(vinyl chloride)-poly(8-caprolactone) at 70 °C. The major disadvantage of this technique is the radiation damage of the hydrophilic polymer during the SEM scan and the necessity of dehydrating the delivery device (am Ende, 1993). 

Drug release systems, synthetic articular cartilages, ultrafiltration membranes pH-sensitive bio-actuators/sensors drug delivery devices materials for the dehydration process of alcohols, ethanol or methanol organic memory devices separation of organic solute molecules from water or electrolyte membranes for fuel cell applications... 

---