Osmotic pressure-activated drug delivery

Osmotic pressure-activated drug delivery systems... 

Osmotic Pressure-Activated Drug Delivery Systems... 

Fig. 19 (A) Cross-sectional view of the Alzet osmotic pump, an osmotic pressure-activated drug-delivery system. (B) The effect of 7 days of subcutaneous delivery of antidiuretic hormone (vasopressin) on the daily volume of urinary excretion and urine osmolality in the Brattleboro rats with diabetes insipidus.

Fig. 20 Cross-sectional view of a unit of Acutrim tablet, a solid-type osmotic pressure-activated drug delivery system, and the effect of increased osmotic pressure in the dissolution medium on the release profiles of phenylpropanolamine HCl from the Acutrim tablet at intestinal condition. (Adapted from Refs.P - l)...

For a solution-type osmotic pressure-activated CrDDS, the intrinsic rate of drug delivery Qjt) is defined by ... 

Primary physiological function Regulates osmotic pressure and pH Multifunctional transporter Relevant in biocompatibility and drug delivery Blood clotting Relevant in biocompatibility and drug delivery Defense mechanism Transport Hormone with intensive effects on metabolism Binding and compaction of DNA in the chromatin. Gene activation... 

A multireservoir osmotic system is described in which the drug is more protected from the influx of water than in the previously described delivery system. The design consists of a central reservoir, formed from a water-impermeable layer containing a liquid active agent and osmotic agent separated by a barrier layer (Fig. 7.6). The barrier layer prevents mixing of the layer contents and minimizes the residual amount of the active agent after the expandable osmotic composition has ceased its expansion. The layer also provides uniform pressure transfer from the... 

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