96-well plate format
5µL sample volume
1 minute assay
Subvisible Particles Are Important to Small Molecule Drugs
Solubility of an active ingredient for small molecule development is just as important as subvisible particles (SVPs). The particle size can affect the solubility of the drug itself.
Aura+ with Backgrounded Membrane Imaging (BMI) enables high throughput screening to characterize and understand how the distribution of all particles and its respective sizes impact the solubility of the drug. Small molecule drug developers can now quickly identify the best conditions and concentrations required to maintain compound solubility without sacrificing precious sample or time.
Analysis for wide range of particle sizes with BMI.
More Sensitive Kinetic Solubility Measurement
To demonstrate correlation of subvisible particle counts measured on Aura systems to solubility changes, four control compounds with different aqueous solubilities were selected for analysis with BMI. A concentration series for each compound was prepared directly from DMSO stocks, then diluted into PBS, pH 7.4 to 1% DMSO final concentration.
Compound Solubility Profiles on Aura. Relationship between increasing concentration in PBS 7.4 and surface coverage of the membrane well with insoluble particles. Differing compound profiles support emergence of particle aggregates as an indicator of solubility of the different compounds. Of note is that the inflection of the particle coverage curves and rate of increased precipitate formation vary for each compound.
Kinetic solubility range for each compound was reported as the concentration above and below where membrane area coverage by particles exceeded a baseline threshold. The midpoint of this range was assigned as the compound’s estimated solubility.
Kinetic solubility measurement of TIPT on the Aura system. Threshold for solubility was set at 0.5% of well area coverage signal saturation.
Kinetic solubility measurement of Dipyridamole on the Aura system. Threshold for solubility was set at 0.5% of well area coverage signal saturation
Kinetic solubility measurement of Griseofluvin on the Aura system. Threshold for solubility was set at 0.5% of well area coverage signal saturation
Kinetic solubility measurement of Diclofenac on the Aura system. Threshold for solubility was set at 0.5% of well area coverage signal saturation
Ranking of the four test compounds for solubility with the Aura system was identical to ranking by turbidimetry. However, with Aura particle aggregates were detected at 5–10 times lower compound concentration.
The Value of the Unseen
Small scale synthesis of compounds during selection stage can lead to variation of physical form, which can have a dramatic effect on the measured aqueous solubility of compounds. BMI provides high resolution images and digital image analysis of aggregate particles to aid in evaluation of solid-state form.
Brightfield image acquired on the Aura of crystalline particles
Brightfield image acquired on the Aura of needle-shaped particles
Brightfield image acquired on the Aura of amorphous solid particles.
Featured product
Aura+
With the ability to support the full range of development and manufacturing applications across therapeutic approaches—including protein/antibody therapeutics, gene therapies, cell therapies, and small molecules— Aura+ packs powerful flexibility into a single particle analyzer.
Features
- 5 µL to 10 mL volume
- Particle characterization for protein, cell and gene therapeutics
- Three fluorescent channels for particle identification
- 4x and 20x magnification imaging
