Drug loading of single nanoparticles as a function of size

We have successfully demonstrated the capability to measure drug mass per nanoparticle as a function of the particle diameter. This is a unique measurement that no other technique can achieve. 

Measurements were carried out on pharmaceutical grade liposomal formulations Doxil® and Onivyde® that were provided by the Nanotechnology Characterization Lab (NCL), Maryland, USA.

From Figure 1, it is evident that the doxorubicin load in mass is constant across the size range, showing a narrow distribution. This suggests that the drug loading by mass is not dependent on the liposome size, and that very small variations in drug mass are present across the liposome population.

In contrast to what we observed for Doxil, Figure 2 shows that in Onivyde the irinotecan mass per nanoparticle increases with size showing a broader distribution, suggesting that the amount of drug mass in this formulation is highly dependent on the nanoparticle size distribution, and as a result, bigger liposomes encapsulate a higher content of drug.

If you would like to see the full results and experimental data, this is available in our application note.

Oxford HighQ has developed an innovative technology based on optical microcavities for nanoparticle (NP) characterisation. Our technology can detect and measure single nanoparticles in real time, giving detailed information on their properties including drug loading in mass per nanoparticle for both encapsulated and surface-coated nanoparticles.

We have also successfully demonstrated real time measurements of:

Shell thickness distribution of core-shell nanoparticles
on a particle-by-particle basis

Drug loading and offloading profile of an API from
mesoporous silica nanoparticles on a particle-by-particle basis

Nanoparticle Size Distribution

Laboratory demonstration instruments are currently available to perform proof-of-capability measurements on customer samples and our first production version of the nanoparticle analyser for nanomedicine applications is entering its final development stage and will be shipping in 2021.

If you would like to receive updates including copies of our application and technical notes or are interested in having samples measured, please complete our contact request form.


Drug unloading from mesoporous silica nanoparticles

Figure 1: Doxorubicin mass measured per nanoparticle as a function of the liposome diameter

Nanoparticle Analyser

Figure 2: Irinotecan mass measured per nanoparticle as a function of the liposome diameter