Osmotic Devices

Eckenhoff et al. (1990) prepared osmotic implant devices containing PST in a glycerol, gelatin, and L-histidine gel. The device had an exit passageway for the gel and separate compartments for the osmotic driving excipients and the PST gel. The in vitro dissolution studies demonstrated controlled release for a 2-month period. 

Effects in Finishing Hogs Treated with PST-Containing Osmotic Devices  

Animal treatment Cumulative average average daily gain Cumulative feed consumption Cumulative feed efficiency s 

Comparison of Deliveiy Rates at Six Weeks of Osmotic Devices Implanted in 

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AG Thombre, GM Zentner, KJ Himmelstein. Mechanism of water transport in controlled porosity osmotic devices. J Membrane Sci 40 279-310, 1989. 

F Theeuwes. Osmotic device having microporous reservoir. US Patent 3,977,404, 1977. 

D Swanson, D Edgren. Osmotic device that improves delivery properties in situ. US Patent 4,326,525, 1982. 

R Cortese, F Theeuwes. Osmotic device with hydrogel driving member. US Patent 4,327,725, 1982. 

Wong, P, Barclay, B., Deters, J., and Theeuwes, F., Osmotic device for administering certain drugs, US Patent 4765989, 1988. 

Figure 7.4 Different types of constructions of osmotic devices. (Adapted from Dong 9)...

Figure 7.6 Design of an osmotic device for a liquid active agent with a water-impermeable coat. (Adapted from Dong.20)...

Theeuwes, F, and Ayer, A. D. Osmotic devices having composite walls, U.S. Patent 4,077,407, 1978. 

The forerunner of modem osmotic devices was the Rose-Nelson pump. Rose and Nelson were two Australian physiologists interested in the delivery of drugs to the gut of sheep and cattle [11], Their pump, illustrated in Figure 12.16,... 

Wong, P.S.L. Theeuwes, F. Larsen, S.D. Song, L.C. Osmotic Device for Delayed Delivery of Agent. US Patent... 

The rate of water diffusing into the osmotic device is expressed as> ... 

The forerunner of modern osmotic devices was the Rose-Nelson pump. Rose and Nelson were two Australian physiologists interested in the delivery of drugs to the gut of sheep and cattle. Their pump, illustrated in Fig. 7, consists of three chambers a drug chamber, a salt chamber containing excess solid salt, and a water chamber.The drug and water chambers are separated by a rigid, semipermeable membrane. The difference in osmotic pressure across the membrane moves water from the water chamber into... 

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