special drug delivery system

SPECIAL DRUG DELIVERY SYSTEM

Ocuserts – Thin elliptical microunits  e.g  pilocarpine ocuserts

Progetagerts – I/U contraceptive device

Transdermal patch  e.g  hyoscine, GTN,  fentanyl, nicotine

Prodrug  -  e.g levodopa

Liposomes

ž  Small artificial vesicles of spherical shape that can be produced from natural nontoxic phospholipids  & cholesterol.

ž  Because of their small size, hydrophilic & hydrophobic character as well as biocompatibility,

                                --promising  system for drug delivery.

Based on their size and number of bilayers.   

•       Small unilamellar vesicles

•       Large unilamellar vesicles

•       Multilamellar vesicles

                Bilayer component determine the rigidity and charge of bilayer.

      Depending on charge there are two types  of

         liposomes, cationic and anionic liposomes

Lipid formulations of AMB have been  produced

•       Liposomal amphotericin B -- consist of 10% AMB incorporated in uniform sized (60-80nm) unilammelar liposomes made up of lecithin

•       Liposome mediated cytotoxic drug delivery e.g.doxorubicin, cisplatin

•       Gene delivery for CFTR in cystic fibrosis.

ž  polymeric  nanoparticles

•       Biodegradable polymers

•       Because of their small size, can penetrate through smaller capillaries can be taken up by cells,   which allow efficient drug accumulation at the target sites.

•       Nanocapsules could perform like miniature man- made viruses, but they will release a pharmaceutical within the target cell, instead of delivering nucleic acid upon penetration of the cell membrane

Computerised minature pump – e.g   insulin,GnRH

Monoclonal antibody as drug carriers–   trastuzumab, rituximab

Zydus  -- mouth desolving tablet – e.g antiemetic drug

GENE THERAPY

                Introduction of functional genetic material into target cells to replace or supplement  defective genes, or to modify target cells so as to achieve therapeutic goals