Showing posts with label Drug Delivery. Show all posts
Showing posts with label Drug Delivery. Show all posts

Tuesday, June 9, 2009

New Drug Delivery Technique

New Drug Delivery Technique Avoids NeedlesBy Sarah Graham

Hypodermic needles are the stuff of nightmares for many people, but they represent a common method for administering a variety of drugs. Patients who fear a needle prick, however, may soon have an alternative, painless way to receive medication. A new technique described today in the journal BMC Medicine uses a stream of gas to help deliver drugs through the skin with what subjects describe as the sensation of a gentle stream of air.

James Weaver of the Massachusetts Institute of Technology and his colleagues developed the novel procedure, which is known as microscission. It uses minuscule inert crystals of aluminum oxide to remove the rough outer layer of skin and create tiny holes, known as microconduits and measuring less than a quarter of a millimeter in diameter, through which medication can move. A jet of flowing gas then takes the crystals and the loosened skin away. After creating four microconduits on the inner arm of volunteers, the team applied a pad soaked in the anesthetic lidocaine. Within two minutes, the drug had worked and the subjects reported no feeling in the region.

The size and depth of the microconduits is determined by holes punched in a polymer mask laid on top of the skin. The team reports that "the onset of anesthesia takes longer in microconduits deep enough to yield blood than in shallower, nonblood producing microconduits." But deep microconduits do have some advantages. Patients suffering from diabetes, for example, often have to jab a finger to test their blood sugar; microscission could represent a less painful alternative, the team suggests.

Source>http://www.scientificamerican.com/

Capsules Encapsulated

Drug Deliver With Nanotechnology:
Capsules Encapsulated
ScienceDaily (May 20, 2009)

—> When cells cannot carry out the tasks required of them by our bodies, the result is disease. Nanobiotechnology researchers are looking for ways to allow synthetic systems take over simple cellular activities when they are absent from the cell. This requires transport systems that can encapsulate medications and other substances and release them in a controlled fashion at the right moment.

The transporter must be able to interact with the surroundings in order to receive the signal to unload its cargo. A team led by Frank Caruso at the University of Melbourne has now developed a microcontainer that can hold thousands of individual "carrier units"—a "capsosome". These are polymer capsules in which liposomes have been embedded to form subcompartments.
Currently, the primary type of nanotransporter used for drugs is the capsule: Polymer capsules form stable containers that are semipermeable, which allows for communication with the surrounding medium. However, these are not suitable for the transport of small molecules because they can escape. Liposomes are good at protecting small drug molecules; however, they are often unstable and impermeable to substances from the environment. The Australian researchers have now combined the advantages of both systems in their capsosomes.
Capsosomes are produced by several steps. First, a layer of polymer is deposited onto small silica spheres. This polymer contains building blocks modified with cholesterol. Liposomes that have been loaded with an enzyme can be securely anchored to the cholesterol units and thus attached to the polymer film. Subsequently, more polymer layers are added and then cross-linked by disulfide bridges into a gel by means of a specially developed, very gentle cross-linking reaction. In the final step, the silica core is etched away without damaging the sensitive cargo.
Experiments with an enzyme as model cargo demonstrated that the liposomes remain intact and the cargo does not escape. Addition of a detergent releases the enzyme in a functional state. By means of the enzymatic reaction, which causes a color change of the solution, it was possible to determine the number of liposome compartments to be about 8000 per polymer capsule.
"Because the capsosomes are biodegradable and nontoxic", says Brigitte Staedler, a senior researcher in the group, "they would also be suitable for use as resorbable synthetic cell organelles and for the transport of drugs." In addition, the scientists are planning to encapsulate liposomes filled with different enzymes together and to equip them with specific "receivers" which would allow the individual cargo to be released in a targeted fashion. This would make it possible to use enzymatic reaction cascades for catalytic reaction processes.

Source:Wiley-Blackwell (2009, May 20).
Drug Deliver With Nanotechnology:
Capsules Encapsulated.
ScienceDaily. Retrieved June 11, 2009,
from> http://www.sciencedaily.com/ /releases/2009/05/090519134717.htm

Drug Delivery Systems

Drug Delivery SystemsMarkets and Applications for Nanotechnology Derived Drug Delivery SystemsBackgroundThe most promising aspect of pharmaceuticals and medicine as it relates to nanotechnology is currently drug delivery. In the words of LaVan and Langer: ‘It is likely that the pharmaceutical industry will transition from a paradigm of drug discovery by screening compounds to the purposeful engineering of targeted molecules.’
Reasons Why the Drug Delivery Market is Rapidly Expanding At present, there are 30 main drug delivery products on the market. The total annual income for all of these is approximately US$33 billion with an annual growth of 15% (based on global product revenue). Two major drivers are primarily responsible for this increase in the market. First, present advances in diagnostic technology appear to be outpacing advances in new therapeutic agents. Highly detailed information from a patient is becoming available, thus promoting much more specific use of pharmaceuticals. Second, the acceptance of new drug formulations is expensive and slow, taking up to 15 years to obtain accreditation of new drug formulas with no guarantee of success.
How Drug Companies are Reacting to this Expansion In response, some companies are trying to hurry the long clinical phase required in Western medicine. However, powerful incentives remain to investigate new techniques that can more effectively deliver or target existing drugs (Saxl, 2000). In addition, many of these new tools will have foundation in current techniques: a targeted molecule may simply add spatial or temporal resolution to an existing assay. Thus, although many potential applications are envisaged, the actual near future products are not much more than better research tools or aids to diagnosis. These are summarised in the following three tables.
More details see >> AZoNanotechnology Article

Friday, June 5, 2009

Nanoparticles Home in on Brain Cancer

Nanoparticles Home in on Brain Cancer
By Nikhil Swaminathan
November 17, 2006

Call them laser-guided smart bombs for brain tumors. Researchers at the University of Michigan announced the testing of a drug delivery system that involves drug-toting nanoparticles and a guiding peptide to target cancerous cells in the brain. Their study finds that via this method more of the drug can be delivered to a tumor's general vicinity. They report their findings in the November 15 issue of Clinical Cancer Research.
The researchers used a pharmaceutical called Photofrin, which is photodynamic, meaning it is activated by a laser after it has entered the bloodstream. As its primary side effect, the drug renders patients photosensitive, and they must remain out of bright sunlight and even unshaded lamps for up to 30 days after receiving treatment. Despite this major drawback, Photofrin is used in the treatment of esophageal, bladder and skin cancers. But their novel delivery system, which relies on the intravenous delivery of 40-nanometer-wide particles to carry the drug, may actually avoid much of the photosensitivity, because less Photofrin circulates in the bloodstream thanks to a peptide called F3. A sequence of 31 amino acids broken off of the protein HMGN2 (high mobility group protein 2), F3 has the ability to penetrate cell membranes. "This peptide acts as a "zip code" in that it enables the binding of the nanoparticles only to blood vessels within the tumor and not normal blood vessels," says Alnawaz Rehemtulla, a radiologist and environmental health scientist who co-authored the study. F3 can detect the expression of a protein called nucleolin, which is a marker on the surface of tumor cells.
Another problem the researchers avoided was having to deliver their medicine in such a way that it could cross the blood-brain barrier, which keeps many substances from entering the brain from the bloodstream. Typical chemotherapies must penetrate this shield to treat tumors. In this case, however, the nontoxic polyacrylamide particles didn't have to cross over via the bloodstream. "The nanoparticles do not need to cross the blood-brain barrier as they were specifically designed to target the blood vessel cells within the tumor," explains radiologist Brian Ross, one of the study's authors. "The treatment should be thought of as an antivascular treatment thereby shutting off the tumor blood flow resulting in the death of the tumor cells through starvation of oxygen and energy sources."
To test the delivery method, researchers divided 34 rats--all who received injections of cancerous cells into their brains--into different groups. Those that received no treatment or got only the laser fared poorly, dying on average within 8.5 days. Those that got Photofrin either intravenously or encapsulated in nanoparticles had a median survival time of 13 days. The group that got F3 with the Photofrin-carrying nanoparticles came through the best: they lived for, on average, 33 days; three of the five in this grouping lived for 60 days, and two of those three appeared tumor-free after six months. By using iron oxide as a contrast agent--to more easily detect where the nanoparticles ended up via MRI--the group determined that twice as much drug with the F3 peptide attached reached the tumor site--10 percent of the total amount administered--compared with when nontargeted nanoparticles were injected.
Ross says that based on the success of the study, the team is investigating if this delivery technology will work for nonphotodynamic therapies. Rehemtulla adds that if other FDA-approved chemotherapeutic agents reach their targets as successfully as Photofrin did, "then we will have developed a way to make cancer drugs more 'tumor-specific,' because they will only get into tumor vasculature and not normal vasculature. This will spare patients from normal tissue toxicity that is commonly associated with almost all chemotherapy."

Source>http://www.scientificamerican.com/article.cfm?id=nanoparticles-home-in-on

Nanocontainers Deliver Drugs

Nanocontainers Deliver Drugs Directly to Cells
By Sarah Graham
April 28, 2003

One challenge to effective drug treatment is getting the medication to exactly the right place. To that end, researchers have been investigating myriad new methods to deliver pharmaceuticals. Findings published in the current issue of the journal Science indicate that tiny nanocontainers composed of polymers may one day distribute drugs to specific spots within individual cells.
Radoslav Savic and his colleagues at McGill University tested the properties of tiny units built out of two types of polymers. The two compounds self-assemble into a spherical shape known as a micelle. One compound, which is hydrophobic (water fearing), aligns facing inwards and the other, which is hydrophilic (water loving), faces outwards. Drugs can then be loaded inside the tiny molecular globs, which measure 20 to 45 nanometers in diameter. The researchers used fluorescent labeling to track the micelles' journeys (see image). They found that the tiny containers could pass through the wall of a rat cell, but did not enter the cell's nucleus. The micelles did, however, penetrate some cell parts, such as mitochondria and the Golgi apparatus, which are important targets for drug delivery.
The scientists also determined that the micelles are very efficient at delivering their hydrophobic drug cargo once inside a cell. This property could mean that doctors may one day be able to administer smaller doses of toxic medications. "These micelles may thus be worth exploring for their potential to selectively deliver drugs to specified subcellular targets," the authors note. In an accompanying commentary, Jeffrey A. Hubbell of the University of Zurich cautions that much work remains to be done, "yet, multifunctional polymer micelles have already come a long way to reaching these ends."

Source >http://www.scientificamerican.com/article.cfm?id=nanocontainers-deliver-dr

New Drug Delivery

New Drug Delivery Technique Avoids NeedlesBy Sarah Graham

Hypodermic needles are the stuff of nightmares for many people, but they represent a common method for administering a variety of drugs. Patients who fear a needle prick, however, may soon have an alternative, painless way to receive medication. A new technique described today in the journal BMC Medicine uses a stream of gas to help deliver drugs through the skin with what subjects describe as the sensation of a gentle stream of air.

James Weaver of the Massachusetts Institute of Technology and his colleagues developed the novel procedure, which is known as microscission. It uses minuscule inert crystals of aluminum oxide to remove the rough outer layer of skin and create tiny holes, known as microconduits and measuring less than a quarter of a millimeter in diameter, through which medication can move. A jet of flowing gas then takes the crystals and the loosened skin away. After creating four microconduits on the inner arm of volunteers, the team applied a pad soaked in the anesthetic lidocaine. Within two minutes, the drug had worked and the subjects reported no feeling in the region.

The size and depth of the microconduits is determined by holes punched in a polymer mask laid on top of the skin. The team reports that "the onset of anesthesia takes longer in microconduits deep enough to yield blood than in shallower, nonblood producing microconduits." But deep microconduits do have some advantages. Patients suffering from diabetes, for example, often have to jab a finger to test their blood sugar; microscission could represent a less painful alternative, the team suggests.

Source>http://www.scientificamerican.com

Friday, May 22, 2009

Drug delivery

Drug delivery is a process, during which pharmaceutical compounds are delivered to humans or animals. Methods of delivery include several routs, such as oral, nasal, pneumonial, rectal and several others. In order to work effectively, the drug needs to work in a controlled manner, which would control the circulation of the drug in the body. Targeted delivery occurs when the drug remains active within a specified territory of the body. Targeted drug delivery is especially important in cases, when the drug needs to affect a malicious turmoil, such as in cancerous tissues.
Doctors all over the world are trying to find new methods for more effective drug development and drug delivery. One of the most successful methods developed in recent years is nanotechnology. This mechanism, which controls small-scale matter, makes it possible for drugs to permeate trough cell walls. The methods of nanotechnology play a very important role in pharma industry: health organizations manufacture more efficient drugs, released in a controlled manner in order to reach the target areas of the patients' body.
Drug development aims to find more effective drugs, which would cure or ameliorate symptoms of illness or medical condition. Drug development is required to establish the chemical properties of new compounds, their stability and chemical makeup. The process of drug development also involves the need to fit the regulatory requirements of drug licensing authorities. Pharmaceutical companies, which produce different medications, develop new methods of targeted drug delivery. Nanotechnology, developed in recent years may provide a breakthrough technique of drug delivery.
Submitted by Natalie Halimi - Content Editor in Internet Marketing Company - Inter-Dev http://www.inter-dev.co.il/en/ Drug delivery, drug development - http://www.docoop.com/

Thursday, May 21, 2009

Release of neurological drugs



Drug Delivery Systems
Markets and Applications for Nanotechnology Derived Drug Delivery Systems
Background
The most promising aspect of pharmaceuticals and medicine as it relates to nanotechnology is currently drug delivery. In the words of LaVan and Langer: ‘It is likely that the pharmaceutical industry will transition from a paradigm of drug discovery by screening compounds to the purposeful engineering of targeted molecules.’

Reasons Why the Drug Delivery Market is Rapidly Expanding
At present, there are 30 main drug delivery products on the market. The total annual income for all of these is approximately US$33 billion with an annual growth of 15% (based on global product revenue). Two major drivers are primarily responsible for this increase in the market. First, present advances in diagnostic technology appear to be outpacing advances in new therapeutic agents. Highly detailed information from a patient is becoming available, thus promoting much more specific use of pharmaceuticals. Second, the acceptance of new drug formulations is expensive and slow, taking up to 15 years to obtain accreditation of new drug formulas with no guarantee of success.

How Drug Companies are Reacting to this Expansion
In response, some companies are trying to hurry the long clinical phase required in Western medicine. However, powerful incentives remain to investigate new techniques that can more effectively deliver or target existing drugs (Saxl, 2000). In addition, many of these new tools will have foundation in current techniques: a targeted molecule may simply add spatial or temporal resolution to an existing assay. Thus, although many potential applications are envisaged, the actual near future products are not much more than better research tools or aids to diagnosis. These are summarised in the following three tables.

More details see >> AZoNanotechnology Article