Drug stability testing is a critical stage of R&D, quality control (QC), and quality assurance (QA) for pharmaceutical products. It typically comprises accelerated aging of a product under simulated use conditions to determine the shelf life of solid phase or colloidal pharmaceuticals.
Colloidal pharmaceuticals include vaccines, ophthalmic suspensions, inhalants, and dermatological lotions. These are comprised of heterogeneous mixtures of biologically active ingredients (AIs) and a suitable drug-delivery medium. Vaccines, for example, contain just a few micrograms (μg) of antigenic material specific to individual vaccinations. The remaining volume of the drug may contain a range of added ingredients including immunological adjuvants, stabilizers, and preservatives. Drug stability testing of vaccines requires intra-particle kinetics to be monitored in response to real-life destabilization phenomena such as temperature and agitation.
The Turbiscan is equipped to perform quantitative monitoring of vaccine stability for cell volumes as small as 4ml up to a maximum temperature of 80°C. But on-demand adapters can also be studied in order to measure the stability of your sample directly in their container (syringe, vial…). Particle migration and velocity of motion are detected using Multiple Light Scattering (MLS) technology, a non-invasive optical technique that can measure particles across a sample concentration of 0.0001 – 95%. Samples are subsequently characterized in their native state (i.e. without mechanical deformation or dilution), with measurements of destabilization mechanics being carried out as a function of temperature and time. Analysts can accurately simulate real-world usage or storage conditions to accelerate vaccine aging for accurate drug stability testing.
Creams and ointments are topical medicines that are applied to body surfaces, typically the skin. These are often unstable amorphous emulsions of either oil-in-water or water-in-oil compositions, with any number of AIs, dermatologically-friendly lipids, or scented agents. Sedimentation of particles in creams and ointments is less common than in more aqueous solutions such as vaccines, given their widely different rheological properties.
Drug stability testing of creams and ointments is often carried out to determine an emulsion’s tendency towards creaming or coalescence. Conventional drug stability testing is unsuitable for such complex emulsions as they require samples to be diluted and mechanically agitated to encourage particle migration. This often results in inaccurate representations of the creaming and coalescence of dermatological creams in real-use conditions.
The Turbiscan TOWER is a robust particle analyzer operating on the proprietary principles of MLS. It boasts an expanded temperature range of 4 – 80°C and can provide in-depth analysis of the migration velocity and hydrodynamic diameter of particles in 6 samples at a time. This provides robust drug stability testing of complex emulsions at high concentrations and opaque optical properties, providing quantitative insights into the destabilization mechanics of pharmaceutical creams in real-world conditions.
Formulaction specializes in the characterization of drug stability and product shelf lives in response to real use or storage conditions. Our proprietary method of MLS offers unmatched particle migration analysis irrespective of sample color and concentration.
Stability Testing of Pharmaceutical Dispersions is a complex process. Feel free to contact us or visit our library section to download related documents if you would like any more information about our innovative drug stability testing products, methods, and services.