Extended release

vs

Delayed release

Extended release= drug available over an extended period of time

Delayed release= drug released later time (not immediately)

KCl 

slow release = less GI irritation

Prevents high local conc of K+

Swelling/Eroding matrix

hydrates and swells over time to inc SA

ciprofloxacin HCl

gastroretentive system(drug release controlled in Stomach)

matrix controlled release

-drug release in stomach allows max abs in intestine

Spansules made by Glaxo-Smith-Kline

Coated Rx(prolong drug release)

Spheroidal Oral Drug Absorption System (Elan)

uniform, 1-2 mm beads of drug plus excipients are surrounded by layers of soluble and insoluble polymers.

EX: VERELAN

Chronotherapeutic Oral Drug Absorption System

enables delay in the release of the drug

Verelan PM = used chronotherapeutically, whereby the drug is not released until 4 to 5 hours after ingestion

-Kadian (morphine sulfate) ER capsules=

[PEG dissolves quick,enteric polymer dissolves at high pH, allowing more drug to diffuse out in GI]

EMbeda

pellets of drug beads 

 membrane coated pellet

sequestered coating>surrounded by Rx>surrounded polymer coating

Intestinal Protective Drug Absorption System

Membrane-Matrix Hybrid-beads wi semipermeable membrane

-semipermeable membrane & osmotic pressure

-GITS  GI systems (Alza)

-two osmotically active compartments

-from laser drilled hole

ex: Procardia-XL,CONCERTA,COVERA

Concerta (methylphenidate HCl)[2 conc inside]

variation of GITS

Covera HS (drug taken at HS will start to work in a.m)

intervening layer

[product shud end up in stool]

Delsym Suspension (Dextromethorphan Polistirex)- q12 h vs q 4 to 8h

tussionex

pennkinetic sys

(ion-exchange resin coated with non dissolving polymer)