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The world of drug delivery is getting more and more efficient every day with new forms of products, which are directly targeting the deficient organs. Dispersed systems such as emulsions (simple or multiple) or nanoparticle suspensions (metal oxides, etc.) are now widely used as drug carriers or nutritional solutions in this purpose. These new forms of products allow better targeting and assimilation for the patient, and give rise to new solutions for drug designers.

However, size measurement is very important as the product can get hazardous in case of agglomeration or aggregation. The size of the product in its native state is of great interest to reflect particles behavior in real conditions. Turbiscan measures particle size of drug dispersions from product development to quality control, in a large concentration and size range (10 nm to 1000µm).

  • Vaccines: kinetics of particles aggregation (proteins denaturation, metal oxides agglomeration…)
  • Skin lotion and cream: detection of particles size evolution due to coalescence or flocculation
  • Ophthalmic suspension: measurement of the active ingredient size after storage
  • Inhalers (pMDI): study of particles size variation due to aggregation in pressurized measurement cells

Documentation

Particles are commonly used in the coating industry, like titanium dioxide which is the most important white pigment used. They are widely used for their efficiency to scatter the light for coating applications. Nevertheless, bad dispersibility can affect its performance as it will decrease its opacifying efficiency.

Turbiscan enables to measure Dispersibility ratio (as defined by ISO 18748) and size after process in a large concentration and size range (10 nm to 1000µm).

  • Dispersibility measurement of talc : effect of dispersant on size of the concentrated dispersion
  • Mechanical mixing effect on titanium dioxide particles size

Documentation

Polymers (polysaccharides, plant proteins…) are widely used in the industry to control viscosity, provide end use properties and enhance the shelf life. Depending on the polymers concentration, emulsions form depletion or percolation networks. Such networks form flocs or droplet networks, they are sensitive to shear or dilution.

Turbiscan enables to measure droplets size at rest and to monitor in real time flocculation on the native product as flocs are sensitive to dilution and shear.

  • Food : predicting long term stability by measuring initial droplet size variation
  • Plant protein : droplet size measurement on the native emulsions, evaluation of the protein efficiency on the size value.

Documentation

Size measurement

Particle size and its evolution versus aging time are key parameters which have to be controlled. Liquid suspensions in industry are very complex mixtures as several components are dispersed and in equilibrium. Turbiscan is a powerful tool to measure the mean particle size on concentrated media, as no dilution nor sample stress are required: the sample is analyzed in its original state thanks to the Static Multiple Light Scattering.
Real dispersion state, such as presence of agglomerates or flocs, can be easily identified and measured, without altering the real particle size.

Key benefits

  • No Sample dilution
  • Wide range of concentration (10-4 - 95%)
  • Wide range of size (10 nm - 1,000 microns)

How does it work?

Static Multiple light Scattering consists in sending photons in concentrated media. The photons are scattered several times by the group of particles , thereby rapidly losing the incident direction.

For concentrated samples, the measured Backscattering intensity is directly proportional to the photon mean free path l* which directly depends on the particles size (d), the particles concentration (Phi), the refractive index of the particles and continuous phase (np and nf). According to Mie theory, our backscattering signal (BS) can be used to compute particles size:

BS = f (d, Phi, np, nf)

Equivalent spherical mean diameter is obtained on the real concentrated media, without any sample dilution nor preparation.

Read more

Data and key features

> Optical or hydrodynamics diameter

Based on the Mie theory, it is possible to compute the average spherical equivalent diameter of the particles in a concentrated media. 
This computation is based on the refractive index of particles and continuous phase, and the volume fraction of particles in the sample.

Based on the Stokes equation, it is possible to estimate the hydrodynamics mean diameter of the particles during a migration process. The faster the particles move, the smaller they are.
This computation is based on the density of the particles and continuous phase, and the viscosity of the continuous phase.


> Dispersibility ratio

Dispersibility (as defined by ISO 18748) is "a characteristic quantifying the ability of particles to be uniformly distributed in volume [...] and of specified size". It is a key parameter in process for various applications (Carbon nanotubes, graphene, slurries...).

Static Multiple Light Scattering is very well adapted to measure directly the dispersibility, as it can work on concentrated samples without dilution, and without any risk to alter the dispersion state.

Instrument demonstration

Discover our Range

  • > Turbiscan Lab

    THE REFERENCE STABILITY ANALYZER

    Accelerate and document ageing tests for a fast and deep understanding of destabilization mechanisms (creaming, sedimentation, flocculation, coalescence). Turbiscan LAB can be used in both R&D labs for formulation development and QC labs to control the stability of raw materials and final products. 

    Light source 880 nm
    Detection S-MLS
    Cell Volume 4 or 20 ml
    Quantitative monitoring of dispersion stability *
    Migration velocity & hydrodynamic diameter *
    ISO TR 13097 Compliant *
    Disposable glass cells *
    Turbiscan Stability Index (TSI) computation *
    Automatic samples recognition (bar-code) *
    Mean diameter and volume fraction *
    Temperature control RT to 60°C
  • > Turbiscan Tower

    THE NEW REFERENCE, 6 TIMES BETTER

    The brand new spearhead of the Turbiscan range to fully characterise the stability of concentrated dispersions (emulsions, suspensions, foams). Discover its new patented mechanical design, for an even better performance. 

    Light source 880 nm
    Detection S-MLS
    Cell Volume 4 or 20 ml
    Quantitative monitoring of dispersion stability *
    Migration velocity & hydrodynamic diameter *
    ISO TR 13097 Compliant *
    Disposable glass cells *
    Turbiscan Stability Index (TSI) computation *
    Automatic samples recognition (bar-code) *
    Mean diameter and volume fraction *
    Temperature control 4 to 80°C
    Multi-samples 6
  • > Turbiscan AGS

    HIGH-THROUGHPUT STABILITY ANALYZER

    High throughput screening is more and more useful to shorten the formulations time-to-market. Turbiscan AGS integrates the Turbiscan LAB, a robot, a storage station and a smart software for automatic sample handling and treatment. This concept enables an automated management of aging tests from sample storage at different temperatures to shelf-life determination. 

    Light source 880 nm
    Detection S-MLS
    Cell Volume 20 ml
    Quantitative monitoring of dispersion stability *
    Migration velocity & hydrodynamic diameter *
    ISO TR 13097 Compliant *
    Disposable glass cells *
    Turbiscan Stability Index (TSI) computation *
    Automatic samples recognition (bar-code) *
    Mean diameter and volume fraction *
    Temperature control RT to 60°C
    Multi-samples 54
    Storage at 3 different temperatures *