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Osmotically controlled system (ORDS- CT)

-The OROS-CT can be used to target the drug locally to the colon for the treatment of disease or to achieve systemic absorption.-An orifice is drilled through the membrane next to the drug layer -Immediately after the OROS-CT is swallowed, the gelatin capsule containing the push-pull units dissolves -Because of its drug-impermeable enteric coating, each push-pull unit is preventedfrom absorbing water in the acidic aqueous environment of the stomach, and hence no drug is delivered.-As the unit enters the small intestine, the coating dissolves in this higher pH environment(pH >7), water enters the unit, causing the osmotic push compartment to swell and concomitantly creates a flowable gel in the drug compartment.

Osmotically controlled system (ORDS- CT)

-The OROS-CT can be used to target the drug locally to
the colon for the treatment of disease or to achieve systemic absorption.
-The OROS-CT system can be single osmotic unit or may incorporate as many as 5-6 push-pull units,each 4 mm in
diameter, encapsulated within a hard gelatin capsule.
-Each bilayer push pull unit contains an osmotic push layer and a drug layer, both surrounded by a semi permeable
membrane.
-An orifice is drilled through the membrane next to the drug layer
-Immediately after the OROS-CT is swallowed, the gelatin capsule containing the
push-pull units dissolves
-Because of its drug-impermeable enteric coating, each
push-pull unit is preventedfrom absorbing water in the acidic aqueous environment
of the stomach, and hence no drug is delivered.
-As the unit enters the small
intestine, the coating dissolves in this higher pH environment(pH >7), water enters
the unit, causing the osmotic push compartment to swell and concomitantly creates a flowable gel in the drug compartment.
-Swelling of the osmotic push compartment forces drug gel out of the orifice at a rate precisely controlled by the rate of
water transport through the semi permeable membrane
-Drug release begins when the unit reaches the colon
-Drug release begins when the unit reaches the colon.
OROS-CT units can maintain a constant release rate for up to 24 hin the colon or can
deliver drug over a period as short as four hours
-For treating ulcerative colitis,
each push pull unit is designed to prevent drug delivery insmall intestine