Gastrointestinal tract drug delivery absorption

Delivery of either a small or large dose of the drug at the same rate Delivery of drug at the intended site of absorption irrespective of the region of the gastrointestinal tract where that process occurs... 

Rouge N, Buri P, Doelker E (1996) Drug absorption sites in the gastrointestinal tract and dosage forms for site-specific delivery. Int J Pharm 136 117-139... 

A second example is the colon-specific delivery of glucocorticoids linked to dextran via a succinic acid or glutaric acid spacer [256a]. Such conjugates resist hydrolysis in the upper gastrointestinal tract, but are rapidly degraded by bacteria in the colon and caecum where little drug absorption occurs. 

A. H. Staib, D. Loew, S. Harder, E. H. Grayl, and R. Pfab, Measurement of theophylline absorption from different regions of the gastrointestinal tract using a remote controlled drug delivery device, Eur. J. Clin. Pharmacol. 30 95-97 (1986). 

However, it is important to note that the system does not actually facilitate oral transmucosal delivery per se, rather it allows rapid release of the drug in the mouth. The drug is then washed down with the saliva for subsequent absorption in the gastrointestinal tract. 

Bieck PR (1989) Drug absorption from the colon. In Hardy JG, Davis SS, Wilson CG (eds) Drug Delivery to the Gastrointestinal Tract. Ellis Horwood Ltd, Chichester, UK, pp 147-159... 

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