Merits of Novel Drug Delivery System
1. Reduction in the total amount of drug administered over the
period of drug treatment. This contributes to the reduced
incidence of systemic and local side effects.
2. Devoid of first pass metabolism and gastrointestinal tract
degradation.
3. Improved patient compliance resulting from the reduction in
the frequency of doses required to maintain the desired
therapeutic response.
4. Targeting of the drug molecule towards the tissue (or) organ
reduces the toxicity to the normal tissues.
5. Pulsatile and pH dependent systems release the drug whenever
the body demands.
6. Biocompatibility.
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.
Rationale for Site Specific Drug Delivery (Tomilinson, 1991)
1. To reach previously inaccessible domains e.g. intracellular site,
bacteria, viruses parasites etc.
2. Exclusive drug delivery to the specific cells or diseased site in
the body.
3. Reduction in the drug dose and side effects.
4. To control the rate and frequency of drug delivery at the
pharmacological receptor.
5. To protect the drug and the body from one another until it
reaches at the desired site of action.