Role of nanotechnology in New drug delivery system Nanotechnology
Role Of Nanotechnology In New Drug Delivery Systems Nanotechnology is the study, design, creation, synthesis, manipulation, and application of materials, devices, and systems at the nanometre scale. The prefix nano is derived from the Greek word dwarf. One nanometer (nm) is equal to onebillionth of a meter, that is, 10−9 m. This size range holds so much interest as in this range materials can have different and enhanced properties compared with the same material at a larger size. Nanomaterials differ significantly from other materials due to the following two major principal factors: the increased surface area and quantum effects. These factors can enhance properties such as reactivity, strength, electrical characteristics and in vivo behaviour. Nanotechnology and nanoscience are widely seen as having a great potential to bring benefits to many areas of research and applications. The application of nanotechnology in the field of health care has come under great attention in recent times. There are many treatments today that take a lot of time and are also very expensive. Using nanotechnology, quicker and much cheaper treatments can be developed. There is another aspect for using nanotechnology. Normally, drugs work through the entire body before they reach the disease affected area. Using nanotechnology, the drug can be targeted to a precise location which would make the drug much more effective and reduce the chances of possible side-effects. We have recently seen the launch of the first nanodelivery system (DOXIL; Ortho-Biotec), a reformulated version of the anticancer agent doxorubicin. Here the drug is encased within polyethylene glycol (PEG)-coated liposomes less than 200nm in diameter. Because of the sustained release of the drug from the liposome and its long circulation time from the “stealth” ability conferred by the PEG, intravenous treatment is only required every four weeks. The use of PEG to mask a drug from our natural defences has also been used for antibody based therapeutics. An ideal drug-delivery system possesses two elements: the ability to target and to control the drug release. Targeting will ensure high efficiency of the drug and reduce the side effects, especially when dealing with drugs that are presumed to kill cancer cells but can also kill healthy cells when delivered to them. The reduction or prevention of side effects can also be achieved by controlled release. NPDDS provide a better penetration of the particles inside the body as their size allows delivery via intravenous injection or other routes. The nanoscale size of these particulate systems also minimizes the irritant reactions at the injection site. Early attempts to direct treatment to a specific set of cells involved attaching radioactive substances to antibodies specific to markers displayed on the surface of cancer cells. Antibodies are the body’s means of detecting and flagging the presence of foreign substances. Antibodies specific to certain proteins can be mass produced in laboratories, ironically using the cancer cells. These approaches have yielded some good results, and NPDDSs are demonstrating lot of potential in this area. Nanoparticles can be used in targeted drug delivery at the site of disease to improve: · the uptake of poorly soluble drugs · the targeting of drugs to a specific site · drug bioavailability Advantages of Nanoparticles · Increased bioavailability · Dose proportionality · Decreased toxicity · Smaller dosage form (i.e., smaller tablet) · Stable dosage forms of drugs which are either unstable or have unacceptably low bioavailability in non-nanoparticulate dosage forms. · Increased active agent surface area results in a faster dissolution of the active agent in an aqueous environment, such as the human body. Faster dissolution generally equates with greater bioavailability, smaller drug doses, less toxicity. · Reduction in fed/fasted variability. CONCLUSION The emergence of nanotechnology is likely to have a significant impact on drug delivery sector, affecting just about every route of administration from oral to injectable, according to specialist market research firm NanoMarket Nanotechnology is also opening up new opportunities in implantable delivery systems, which are often preferable to the use of injectable drugs, because the latter frequently display firstorder kinetics (the blood concentration goes up rapidly, but drops exponentially over time). This rapid rise may cause difficulties with toxicity, and drug efficacy can diminish as the drug concentration falls below the targeted range. In contrast, implantable time release systems may help minimize peak plasma levels and reduce the risk of adverse reactions, allow for more predictable and extended duration of action, reduce the frequency of re-dosing and improve patient acceptance and compliance. Nano-implants will also be used in the not-toodistant future for treating cancer. Among the first nanoscale devices to show promise in anti-cancer therapeutics and drug delivery are structures called nanoshells, which NanoMarkets believes may afford a degree of control never before seen in implantable drug delivery products. Despite these advances, the vast majority of consumers prefer an oral drug delivery system to implantables or injectables. With this in mind, various development groups are working to enhance traditional oral delivery systems with nanoengineered improvements. There are some areas where nano-enhanced drugs could make a big difference in increasing oral bioavailability and reducing undesirable side effects. By increasing bioavailability, nanoparticles can increase the yield in drug development and more importantly may help treat previously untreatable conditions.
