The Benefits of the Zetasizer

In order to be effective, topical oil-based products, or ‘semisolid’ drugs, need to be able to penetrate the skin in a manner that allows them to be delivered to the body’s circulation. Whether it’s for beauty, medicine or any other purpose, the challenge of delivering semisolids into the body is crucial to the success of any given semisolid product.

Measuring the size of particles within these semisolids is the key to ensuring the product is delivered in the most effective manner. Various methods of particle size measurement or analysis are used to measure these materials, including laser diffraction and dynamic light scattering. Further to this, by using an instrument called the Zetasizer, scientists can also understand the variable effects of pH and temperature on the delivery system.

Dynamic light scattering

In order to guarantee the size of the nanoparticles remains consistent at the pH and temperature that will be found on the human body, the process of dynamic light scattering (DLS) can be used. DLS measures the intensity of scattered light from particles suspended under Brownian motion, before analysing fluctuations. DLS is so sensitive that it can track changes in particle size to less than 1nm across, making it very nicely suited to examining potential particle size shifts in the human body.

pH and temperature changes

By studying the effect of pH changes on the nanoparticles, we can finely tune the molecular change that may result when being applied to the human body. For example, when pH values are low, the diameter of the particles increases; if the pH level is raised again, then it will be restored to its former size. Using this technique allows us to control the size of the nanoparticles in the body. Alternatively, we can also use temperature instead of pH; higher temperatures make nanoparticles more hydrophobic, resulting in larger particle sizes.

An example

Take, for example, the Lipodisq delivery system, which copies the way naturally-occurring HDLs [high-density lipoproteins] bind cholesterol in the body. The nanoparticles of the Lipodisq system are able to find a way through the skin while still carrying the pharmaceutical agents with them to be delivered into the bloodstream – but they need to be exactly the right size. In fact, the suitable size range is very small; if the nanoparticles are larger than 50nm (nanometres) in size, they will not be able to breach the outer layer of the skin. If they’re less than 5-10nm, they will be too unstable to properly transport the required ingredients. Therefore, these nanoparticles must fall somewhere between 10nm and 50nm in order to be effective.

Using the Zetasizer

Particle size analysis technology is already having dramatic benefits to the pharmaceutical industry as the ability for executing controlled releases of semisolids into the body is increased. Any method that achieves particle size measurement can go a long way to aiding in this regard, but the fact that the Zetasizer is capable of taking into account variables such as pH and temperature make it an outstanding tool and one that will undoubtedly be used on a more regular basis.

ATS Scientific offers a range of Zetasizer instruments, so browse our product range today to find the right one for you.