[e-drug] Pharmacokinetics (2)

["Nadeem Irfan Bukhari" <nadeemi@imu.edu.my>]

E-DRUG: Pharmacokinetics (2)
----------------------------

Dear Penguin Shu

Sustained Release
Sustain release tablet is one type of controlled release delivery
system which releases an initial drug sufficient for therapeutic action
and then gradual release over an extended time. Therefore, in a
sustained release tablet, the drug is released in the body at a specific
rate over an extended period of time, allowing optimal therapeutic
effects.  This is reported to be a safe process that allows the patient
to reduce the number of doses.

Controlled release tablet is a tablet which releases a drug in a single
dose at controlled rates to maintain drug concentration in a desired
therapeutic range. Controlled release denotes that the system is able to
provide some actual therapeutic control, whether this be of a temporal
nature, spatial nature, or both. The goal of a sustained-release dosage
form is to maintain therapeutic blood or tissue levels of the drug for
an extended period.

The controlled release actually goes beyond the scope of sustained drug
action since it implies a predictability and reproducibility in drug
release kinetics, Rate-Preprogrammed Drug Delivery Systems Release of
drug molecules has been accomplished by system design which controls the
molecular diffusion of drug molecules. Fick's laws of diffusion are
often followed.

The dosage forms included under controlled relase are the modified
Release (which rlease a relatively large portion of the drug immediately
to provide immediate effects. The remainder is released in a sustained
fashion), Pulsatic Release (releasing designated amounts of the drug 
according to a schedule defined by time delays) and sustained release
(ad defined above).

Long acting tablets release drugs for prolonger perionds. 

Hoping it will be of some help.


Nadeem Irfan Bukhari,
Lecturer, Pharmaceutical Technology,
School of Pharmacy,
International Medical University (IMU),
Bukit Jalil, Kuala Lumpur - 57000
Malaysia
Tel: + 60 86567228; Fax: 86567229
H/P +60 12 3242264
http://www.imu.edu.my
"Nadeem Irfan Bukhari" <nadeemi@imu.edu.my>