New study says nanoparticles don't penetrate the skin

New study says nanoparticles don’t penetrate the skin
The study shows that even the smallest nanoparticles don't penetrate the skin

(Phys.org)—Research by scientists at the University of Bath is challenging claims that nanoparticles in medicated and cosmetic creams are able to transport and deliver active ingredients deep inside the skin.

Nanoparticles, which are that are less than one hundredth of the thickness of a , are used in sunscreens and some cosmetic and pharmaceutical creams.

The Bath study discovered that even the tiniest of nanoparticles did not penetrate the skin's surface.

These findings have implications for pharmaceutical researchers and cosmetic companies that design skin creams with nanoparticles that are supposed to transport ingredients to the deeper layers of the skin.

However the findings will also allay safety concerns that potentially harmful nanoparticles such as those used in can be absorbed into the body.

The scientists used a technique called laser scanning confocal microscopy to examine whether fluorescently-tagged , ranging in size from 20 to 200 , were absorbed into the skin.

They found that even when the skin sample had been partially compromised by stripping the outer layers with , the nanoparticles did not penetrate the skin's outer layer, known as the stratum corneum.

New study says nanoparticles don’t penetrate the skin
This microscopy image shows the nanoparticles in green on the skin's surface

Professor Richard Guy from the University's Department of Pharmacy & Pharmacology, who led the study, said: "Previous studies have reached conflicting conclusions over whether nanoparticles can penetrate the skin or not.

"Using confocal microscopy has allowed us to unambiguously visualise and objectively assess what happens to nanoparticles on an uneven skin surface. Whereas earlier work has suggested that nanoparticles appear to penetrate the skin, our results indicate that they may in fact have simply been deposited into a deep crease within the skin sample.

"The skin's role is to act as a barrier to potentially dangerous chemicals and to reduce water loss from the body. Our study shows that it is doing a good job of this.

"So, while an unsuspecting consumer may draw the conclusion that in their , are 'carrying' an active ingredient deep into the skin, our research shows this is patently not the case."

The results of the work, published in the Journal of Controlled Release, suggest that it might be possible to design a new type of nanoparticle-based drug formulation that can be applied to the skin and give controlled release of a drug over a long period of time.

This would enable sustained delivery of the active drug, potentially reducing the frequency with which the patient would have to apply the formulation to the skin.


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Journal information: Journal of Controlled Release

Provided by University of Bath
Citation: New study says nanoparticles don't penetrate the skin (2012, October 1) retrieved 16 September 2019 from https://phys.org/news/2012-10-nanoparticles-dont-penetrate-skin.html
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Oct 01, 2012
Someone had better come up with an explanation for how Nicotine patches work, then. People can OD on those. I am allergic to nicotine to the extent that I cannot handle tobacco plant leaves. They cause me to vomit if I have been exposed over the course of a two-week duration, as during harvest.

Oct 01, 2012
45 years ago, I was cured from malfunction of the thyroid, just applying a medicated cream on my belly for a while. The doctor said it was better through the skin because my stomach didn't need the cure and was going to destruct 95% of it anyway. Were it full of nano ? or more likely macro? All I know is they went in and did the job! Most of the miracle creams don't work because they are not good, not for lack of reaching.

Oct 01, 2012
Only hydrophillic nanoparticles (like the titanium dioxide) cannot penetrate the skin - with compare to it the hydrophobic nanoparticles (i.e. those miscible with lipids) can penetrate tissues fast. Unfortunately, just these hydrophobic nanoparticles belong into most dangerous ones: they often contain heavy metals and induce cancer.

Oct 01, 2012
45 years ago, I was cured from malfunction of the thyroid, just applying a medicated cream on my belly for a while. The doctor said it was better through the skin because my stomach didn't need the cure and was going to destruct 95% of it anyway. Were it full of nano ? or more likely macro? All I know is they went in and did the job! Most of the miracle creams don't work because they are not good, not for lack of reaching.

You were probably given a topical or transdermal thyroxine preparation if your thyroid levels were low, before the advent of nano-sized pharmaceuticals. You probably would benefit from some dietary seaweed, which would boost your iodine levels, and your thyroid would be thankful.

Baudrunner, you were spared the scourge of tobacco, which has claimed 100,000,000 lives since 1900, due to illness and cancer. Give me a few moments to think of a vice more suited to your makeup.

Oct 01, 2012
Nano-mania is soon to be unleashed on the environment without proper research and precautions. Profit over safety will always prevail. When lead was used in gasoline, toxic lead residue could be found everywhere on earth, even in places where cars were never driven.

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