This document discusses sustained and controlled drug delivery systems. Sustained release drug delivery systems aim to prolong the therapeutic effect of a drug through continuous release over a period of time from a single dose. Controlled release systems automatically deliver drugs at predetermined rates over long periods to maintain constant drug levels. The key difference is that controlled release systems achieve zero-order kinetics to precisely control drug levels, while sustained systems do not necessarily achieve this. Controlled release provides benefits like reduced dosing frequency, fewer side effects, and improved patient compliance. Challenges include potential for dose dumping and stability issues. The rationale is that these systems can deliver drugs locally or target delivery through spatial and temporal control of release.
2. INTRODUCTION
The understanding of pharmacokinetic and
pharmacodynamic behaviours of drugs have a more
rational approach to the optimul drug delivery system
.It has now become apparently appreciable that future
successes in drug delivery research will largely be the
result of multidisciplinary efforts. Novel drug delivery
system (NDDS) are the carriers which maintain the
drug concentration in therapeutic range for longer
period of time .
3. SUSTAINED RELEASE DRUG DELIVERY
SYSTEM :-
Sustained release is repository dosage forms are used
to identify drug delivery systems that are designed to
achieve a prolonged therapeutic effect by continuously
releasing medication on a single dose.
4. CONTROLLED RELEASE DRUG DELIVERY
SYSTEM :-
Controlled release has become associated with those
system from which therapeutic agents may be
automatically delivered at predefined rates over a long
period of time.
5. DIFFERENCE BETWEEN SUSTAINED AND
CONTROLLED DRUG DELIVERY SYSTEMS
SUSTAINED DURG
DELIVERY SYSTEMs
CONTROLLED DRUG
DELIVERY SYSTEMs
SRDF generally do not attain
Zero order release kinetic.
Constitutes dosage form that
provides medication over
extended period of time...
It may or may not be control..
It perfectly Zero order
kinetics..
Constitutes dosage form that
maintain constant drug levels
in blood or tissue..
It can be control..
6. ADVANTAGE OF CRDDS:-
Decreased dosing frequency.
Reduced rate of rise of drug concentration in blood.
Less fluctuation at plasma drug levels.
Enhanced bioavailability.
To achieve a targeted drug release.
Reduced side effects.
Improved patient compliance.
6
7. DISADVANTAGES OF CRDDS:-
Dose dumping.
Reduced potential for accurate dose adjustmant.
Stability problem.
Need of additional patient education.
8. RATIONALE OF CRDDS:-
Sustained or controlled drug delivery system provide
drug action at a predetermined rate by providing a
prolonged or constant release at therapeutically effect
circulation.
Localized drug delivery devices through spatial and
temporal control of drug release presence of the
target..
Targeted drug delivery by using carriers either meant
for passive preprogrammed or self preprogrammed
approach..
9. CONCLUSION:-
Various drug delivery and drug targeting systems are
currently under development. choice of delivary route
is driven by patient acceptability. properties of drug,
access to a disease location.
10. REFERENCE:-
Leon Lachman, Herbert A Lieberman; “The Theory
and Practice of Industrial Pharmacy”, 4th Edition, CBS
Publishers & Distributors Pvt. Ltd ;2013:872-906
Vyas .S.P and Khar R.K; “Controlled Drug Delivery
concepts AND Advances”,5th Edition,CBS Publishers &
Distributors Pvt. Ldt ;2010:1-54
Schacht, E.; Vermeesch, J.; Vandoorne, F.; Vercauteren,
R.(1985) J. Control. Rel.,2:245
Langer, R.; Peppas, N. (1983) J. Macromol. Sci., 23:61