New drug delivery system delivers or aimed at maximizing the drug effectiveness or minimizing the side effects.
Some of the Novel dosage forms are:
1) Implants
2) Controlled drug delivery system
3) Sustained release system
4) Liposomes
5) Erythrocytes
6) Nanoparticles
7) Prodrugs
8) Film and strips.
1) Implants:
The hypodermic tablets are placed under the skin by a minor surgery in order to release drugs over a prolonged periods of time. Now the magnetically controlled implants have been developed which can be opened or closed in order to release or stop the drug. The implants which are in capsule form, consist of a body and a cap. It can be opened by placing a magnet onthe skin and moving it in the desired direction. These implants are placed in the upper thigh at a depth of 5 mm. These implants are useful in hormone therapy
2) Controlled Drug Delivery System: Controlled Drug Delivery Systems are devices which are formed by embedding the drug within polymeric matrix so that it get released slowly to the body over a very long period of time .The polymeric matrices used to hold drug reversibly are polyethylene silicon elastomer and cellulose ester. These controlled drug delivery modules are punctured before administration with laser beam to make a small orifice of a few microns in diameter for the release of drug.
3) Sustained Release system: Sustained released dosage forms are the new drug delivery system. They provide a therapeutic blood level of the drug which is attained rapidly and is maintained within narrow limits over extended period of a time, usually for 10 to 12 hrs. afer administration of single dose. Sustained release of dosage are achieved because they are enteric coated which get released in specific part of body.
4) Liposomes: They are phospholipids which can be transported with hydrophilic and hydrophobic drugs.
Applications:
1) Liposomal drugs are used in diseases caused by intracellular parasites.
e. g. Malaria, Tuberculosis
2) Liposomes can be used to transport functional DNA/RNA molecules into cells.
5) Erythrocytes:
As the life span of Erythrocytes is 120 days drugs are encapsulated in Erythrocytes. The drug release for a prolonged period of time.
Applications:
1) Resealed erythrocytes of asparaginase have shown good results in asparaginase dependant leukaemia.
2) Resealed erythrocytes of methotrexate and adrianycin have been tried in cancer therapy.
6) Nanoparticles:
The particle size ranges from 200-500 nm. The system consists of drug and carrier to deposit the drug at the target site. The carrier used are serum albumin, bovine serum, albumin, gelatin, casein, s ethyl cellulose.
7) Prodrugs:
The compounds that shows desirable pharmacological activity after its metabolism are called as prodrugs. Prodrugs are used to increase solubility, stability and bioavailability of drug, masking the unpleasant taste and odour of the parent drug and reducing the toxicity.
8) Film and strips:
These are meant for topical application for slow release of drug over predetermined period of time. The film and strips which are becoming popular these days are
I. Zero order release film.
II. Buccal Stip.
III. Spray bandages.