Sustained-release medications are usually labeled with “SR” at the end of their name. These medications prolong the medication's release from a tablet or capsule so that you'll get the medication's benefits over a longer period of time. CR = controlled release, SR = sustained release, ER = extended release, IR = immediate release. *

1. SUSTAINED RELEASE (SR) &
CONTROLLED RELEASE (CR)
SUBMITTED BY: RAHUL PAL, PRACHI PANDEY SUBMITTED TO: ARSH CHANANA
M. PHARM (PHARMACEUTICS)
NIMS INSTITUTE OF PHARMACY, NIMS UNIVERSITY JAIPUR, RAJASTHAN INDIA

2. SUSTAINED RELEASE (SR)
The Sustained release are majorly designed to achieve the prolonged therapeutic effect by
continuously releasing medication over the extended period of time usually 8-12 hr., after
single dose administration.
 Especially they provide the medication over extended time of period.
 SR release follow 1st order release kinetics, means depends on concentration.
 In Other words, “The slow release of drug substances from a dosage form to maintain
therapeutic responses for extended period of time”.
Example: Aspirin, Dextrin SR.

3. CONTROLLED RELEASE (CR)
The delivery of the drug medicament at predetermined rate, for locally and systematically
for specified period of time, known as “Controlled release”.
 Maintain the constant drug level in the blood as well as tissues.
 CR release follow Zero order release kinetic, means independence of concentration.
 In short words, “ The formulation which delivers the drug at predetermined rate.”
Example: GITS (Prazosin), Morphine Sulphate (Roxonal SR®)

4. GRAPHICAL REPRESENTATION OF SR/CR
CONTROLLED RELEASED (CR) SUSTAINED RELEASED (SR)

5. STUDY OVERVIEW OF DRUG RELEASE

6. DIFFERENCE BETWEEN SR/CR
SUSTAINED RELEASE (SR)
 Dosage form that provide medication over
extended period of time.
 Follow 1st order release kinetics.
 Usually do not promote localization of the
drug at active site.
 Drug release at programmed rate,
dependent on external environmental.
CONTROLLED RELEASE (CR)
 Dosage form that maintains constant drug levels
in the blood/tissue.
 Follow zero order release kinetics.
 Usually promote localization of the drug at
active site.
 Drug release at predetermined rate,
independent of external environmental.

7. ADVANTAGES OF SR/CR DRUG DELIVERY
a) Reduced GI side effects, and dosing frequency.
b) Improve absorption, enhancing the bioavailability (BA).
c) Bateer patients acceptance and compliance.
d) Decreased the local and systemic side effect.
e) Minimized the accumulation of drug medicament with chronic dosing.

8. DISADVANTAGES OF SR/CR DRUG DELIVERY
a) Dose dumping problem occurred.
b) Stability problem.
c) Cost of single unit dosage form is higher than that of conventional dosage form.
d) Poor In-vitro & In-Vivo correction.
e) Dose adjustment sometime difficult.
f) Patient education is required for the successful therapy.

9. FACTORS AFFECTING THE SR/CR DRUG
RELEASE

10. APPROACHES IN SR/CR DDS

11. DISSOLUTION CONTROLLED RELEASE

12. DIFFUSION CONTROLLED RELEASE

14. APPLICATION OF SR/CR