PRESENTED TO: PRESENTED BY:
Dr. KANCHAN KOHLI NIDHI AGGARWAL
HOD(DEPARTMENT OF M.PHARMA (Pharmaceutics)
PHARMACEUTICS) 1st sem.

SPER, JAMIA HAMDARD

INTRODUCTION
 Most conventional (also named as immediate-release, IR) oral drug

products, such as tablets and capsules, are formulated to release
the active pharmaceutical ingredient (API) immediately after oral
administration.

 In the formulation of conventional drug products, no deliberate effort
is made to modify the drug release rate.

 In order to achieve a desired therapeutic objective or better patient
compliance, the pattern of drug release from modified-release (MR)
dosage forms is deliberately changed from that of a conventional
dosage formulation.

 MR drug products have always been more effective therapeutic
alternative to conventional dosage forms.

 The objective of MR drug products for oral administration is to control
the release of the therapeutic agent and thus control drug absorption
from gastrointestinal tract.

 The term modified-release (MR) drug product is used to describe
products that alter the timing and/or rate of release of the drug
substance in the formulation.

Several types of modified-release
oral drug products are recognized:

• Extended-release drug products:
A dosage form that allows at least a twofold reduction in dosage
frequency as compared to that drug presented as an immediate-release
(conventional) dosage form. Examples of extended-release dosage forms
include controlled-release, sustained-release, and long-acting drug
products.

• Delayed-release drug products:
A dosage form that releases a discrete portion/portions of drug at a time other
than the promptly release after administration. An initial portion may be released
promptly after administration. Enteric-coated dosage forms are common delayed-
release products (eg. enteric-coated aspirin and other NSAID products).

• Targeted-release drug products:
A dosage form that releases drug at or near the intended physiologic site of
action. Targeted-release dosage forms may have either immediate- or extended-
release characteristics.

• Orally disintegrating tablets (ODTs):
ODTs have been developed to disintegrate rapidly in the saliva after oral
administration. ODTs may be used without the addition of water. The drug is
dispersed in saliva and swallowed with little or no water.

SUSTAINED RELEASE
FORMULATIONS

 Sustained-release dosage forms are dosage forms designed to
release (liberate) a drug at a predetermined rate for a specific period
of time with minimum side effects.

 Usually, the drug may be delivered in an initial therapeutic dose,
followed by a slower and constant release.

 The purpose of a loading dose is to provide immediate or fast drug
release to quickly provide therapeutic drug concentrations in the
plasma. The rate of release of the maintenance dose is designed so
that the amount of drug loss from the body by elimination is
constantly replaced.

 SR maintains drug release over a sustained period but not at a
constant rate.

CONTROLLED RELEASE
FORMULATIONS
 Controlled-release formulations are absorbed more slowly than

conventional tablets and produce more stable serum levels
during the day and at night, even when given twice daily as
compared with conventional tablets given three times daily.

 The dosage form in which the drug is released in planned,
predictable and slower than conventional dosage form.

 CR maintains drug release over a sustained period at a
nearly constant rate.

SUSTAINED CONTROLLED
RELEASE RELEASE

DOSAGE FORM DOSAGE FORM

• Provides medication over • Maintains constant drug
extended period of time. levels in blood or tissue.

• Follows first order kinetics. • Follows zero order kinetics.

• Rate of release decreases with • Rate of release does not
decrease in concentration. change with concentration.

• Usually do not contain • Contains methods to promote
localization of drug at the active localization of drug at active
site. site.

Fig: A hypothetical plasma-time profile from conventional multiple
dosing and single doses of sustained and controlled delivery
formulations

ADVANTAGES: DISADVANTAGES:
• Enhance patient compliance and • Increased cost.

convenience.
• Toxicity due to dose dumping.

• Reduction in dosing frequency.
• Unpredictable and often poor

• Reduced fluctuation in
circulating drug levels. in vitro-in vivo correlation.

• More uniform effect. • Risk of side effects or toxicity
upon fast release of

• Reduced toxicity due to contained drug (mechanical
overdose.

failure, chewing or
• Enhanced bioavailability. masticating, alcohol intake).
• Elimination of wastage of drug • Need of additional patient

and inconvenience of night time
administration of drug. education counseling.

• Enhanced duration of activity for
short half-life drugs.

SOME MARKETED
CONTROLLED RELEASE
PREPARATIONS:

API BRAND NAME CLASS

Oxycodone OxyContin Pain relief

Alprazolam Xanax Benzodiazepines

Methadone Methadose Opioid

Hydrocodone & Tussionex Cough suppressant &
Chlorpheneramine Antihistamine

SOME MARKETED
SUSTAINED RELEASE
PREPARATIONS:

API BRAND NAME CLASS

Metformin SR Glucophage Oral hypoglycemic

Naproxen SR Naprelan NSAIDS

Guaifenesin SR Allfen & xpect Expectorant

Quetiapine SR Seroquel schizophrenic

REFERENCES

 Shargel and Yu’s “ APPLIED BIOPHARMACEUTICs AND
PHARMACOKINETCS”, 7th ed.

 https://www.slideshare.net/PrinceDivyesh/controlled-and-
sustained-release-dosage-formcontrolled-release-dosage-
formsuistained-release-dosage-form

 http://www.ijprbs.com/issuedocs/2017/4/IJPRBS%201351.pdf

 International Journal of Pharmaceutical Research and Bio-
science: A REVIEW ON SUSTAINED RELEASE
TECHNOLOGY DRUG DELIVERY SYSTEM