Limitations of Novel Drug Delivery System
1. The drugs having biological half-life of 1 hr. or less are difficult
to be formulated as sustained release formulations. The high
rate of elimination of such drugs from the body needs an
extremely large maintenance dose which provides 8-12 hrs of
continuous therapy.
2. These products normally contain a large amount of drug. There
is a possibility of unsafe over dosage, if the product is
improperly made and the total drug contained therein is
released at one time or over too short time interval.
3. If it is once administered, it may be difficult to stop the therapy
for reasons of toxicity or any other reasons.
4. It may be unwise to include potent drugs in such systems.