Module 3 ALS Flashcards
The surface area of the rectum has no villi, thus has a relatively (high or low) absorptive surface area.
low
The rectal mucosa is the mucous layer of the rectum (rectal fluid) with a volume of ___ ml (100 micrometers thick) and pH of 7.5
3
Rectal fluid is about 3 mL which is very little fluid for drug …
dissolution
The epithelium of the rectal mucosa is cylindrical single cell layer and goblet cells, but it transitions to a _____ epithelium as it reaches the anus.
squamous
______ rectal veins drain to the general circulation (without hepatic first pass metabolism)
lower and middle
____ rectal vein drains to the hepatic portal vein which is more GI-like (with hepatic first pass metabolism)
superior
Venous Anastomoses is the opening; a natural communication between …
two blood vessels
____ can help spread the dosage form and are stimulated by colonic contents– Rectal Motility
Rectal contractions
Advantage of Rectal Drug delivery if the oral route is les desirable for the drug…
Bypass drug inactivation of upper GIT
Partial avoidance of Hepatic first pass metabolism (only absorbed in the lower rectum to bypass portal drainage)
The rate of absorption is not affected by gastric emptying or GI transit time
Disadvantage of Rectal Drug delivery …
Poor, slow, erratic drug bioavailability
- Low surface area
- Low fluid content
- complex blood drainage
(lower suppository placement– avoid portal drainage- which is needed if systemic effect is desirable)
Vehicles for oral liquids- primary solvent used is purified water, since tap water contains …
inorganic and organic impurities includes dissolved inorganic/organic matter (Calcium, Iron, Sulfates)
Purified water is obtained by …
distillation, reverse osmosis, or ion-exchange (end up with very low conc. of dissolved solute)
Syrup vehicles for oral liquids include the most common _____ with a pH of 3.5-4.0
Cherry syrup
Cosolvents work in aqueous media by reducing polarity, water miscible and includes…
alcohol, glycerin, and propylene glycol
Hydroalcoholic mixture (cosolvent in elixirs) is the mixture of water with the cosolvent…
alcohol
Disulfiram-like reactions may occur when taking alcohol-containing products, and this reaction …
cause one to vomit (Flushing, N+V)
Glycerin is a clear _____ liquid with a sweet taste and hard to work with.
viscous
____ is less viscous than glycerin and easier to work with as a cosolvent in oral liquids.
propylene glycol
_____ is a cosolvent and can have toxic effects if it accumulates, such as seizures, hemolysis, and tachycardia.
propylene glycol