Everything about Microspheres
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  • Neutrally Buoyant in Water – Microspheres with Specific Gravity of 1g/cc

    Cospheric offers polymer microspheres with specific gravity of 1g/cc are specifically designed to match the density of water for optimal suspension of particles. Suspension of microspheres in water enables the visualization and characterization of fluid flow and testing the capability of devices to withstand particulate matter in the fluid stream, ensuring that microspheres do not settle and do not float on the surface.  Most of these polymer microspheres are at least moderately opaque and clearly visible in water, clear or translucent liquids.

    Many Colors are available in sizes from 10um up to 1180um,  of polyethylene microspheres are available with specific density of 1g/cc, designed for optimum suspension in water for fluid flow visualization.  Colors include Violet, Orange, Yellow, Fluorescent, Grey, Pink, Blue, and many fluorescent colors.

    600-710um violet PE microspheres250-300um ORANGE PE Microspheresblue microspheres 355-425um Yellow microspheresGrey Microspheres PE

  • FDA-Approved Microspheres

    What makes a microsphere FDA-approved?

    In order to tell whether the microsphere can be used in cosmetics, food, or medical devices it is important to look at the raw materials that are incorporated into the microsphere during manufacturing process.  For example, unpigmented or clear polyethylene microspheres supplied by Cospheric in sizes from 10 micron to 1000 micron meet the quality requirements of the US FDA as specified in 21 CFR 172.888 and 21 CFR 178.3720.  Specific grade of polyethylene used in manufacturing of these microspheres is  FDA-approved for food applications in chewing gum base, on cheese and raw fruits and vegetables, and as a defoamer in food.

    Color additives are subject to a strict system of approval under U.S. law (FD&C Act), sec. 721; 21 U.S.C. 379e. Color additive violations are a common reason for detaining imported cosmetic products offered for entry into this country. If a product contains a color additive, by law [FD&C Act, Sec. 721; 21 U.S.C. 379e; 21 CFR Parts 70 and 80] you must adhere to requirements for:

    • Approval. All color additives used in cosmetics (or any other FDA-regulated product) must be approved by FDA. There must be a regulation specifically addressing a substance’s use as a color additive, specifications, and restrictions.
    • Certification. In addition to approval, a number of color additives must be batch certified by FDA if they are to be used in cosmetics (or any other FDA-regulated product) marketed in the U.S.
    • Identity and specifications. All color additives must meet the requirements for identity and specifications stated in the Code of Federal Regulations (CFR).
    • Use and restrictions. Color additives may be used only for the intended uses stated in the regulations that pertain to them. The regulations also specify other restrictions for certain colors, such as the maximum permissible concentration in the finished product.

    Continue reading “FDA-Approved Microspheres” »

  • Phosphorescent Microspheres – Long Afterglow Particles

    Phosphorecent Beads - Yellow Green Afterglow Spheres

    Phosphorecent Beads - Yellow Green Afterglow

    Phosphorescent microspheres in particle sizes 10 to 600 microns are now available from Cospheric LLC. These phosphorescent particles are 90% spherical and appear to be off-white under ordinary daylight or regular room illumination.  However, when the lights are turned off these phosphorescent particles exhibit phosphorescent yellow-green after-glow.

    The spheres have tight particle size distributions and are > 90% within size range.  Polymer spheres that incorporate proprietary phosphorescent ingredient have a melting point of 115°C , and are mechanically stable past 90°C.  Phosphorescent beads are also inert in most solvents.

    Phosphorescent Decay CurveIntensity of Phosphorescent Afterglow:

    Intensity according to DIN 67510-1

    800 mcd/m2 at 1 minute
    180 mcd/m2 at 5 minutes
    90 mcd/m2 at 10 minutes
    12 mcd/m2 at 1 hour
    5 mcd/m2 at 2 hours

    Excitation and Phosphorescent Emission Curve:
    Excitation and Emission Spectra

  • Microspheres for Medical Devices – MDDI Magazine – January 2011

    The Microsphere of Influence

    Published: January 2011, MDDI

    Published on MDDI Magazine
    By: Yelena Lipovetskaya

    Find more content on: Feature, Nano and Microtechnology, Technology, Testing and Inspection

    Microspheres come in many different grades and sizes, and are usually solid particles that are composed of polymers, glass, and ceramics. All images courtesy of COSPHERIC LLC

    Microspheres are round microparticles that typically range from 1 to 1000 μm in diameter. In the pharmaceutical and cosmetics industry, microspheres are well known for their ability to deliver active materials. This process usually involves the microencapsulation of a drug or an active cosmetic ingredient to protect it from the deteriorating effects of the environment or for optimal release and performance in the final product. Active ingredients are released by dissolution of the capsule walls, mechanical rupture (rubbing, pressure, or impact), melting, or digestion processes. Solid microspheres are widely used as fillers and spacers in a variety of industries.

    Microspheres used to manufacture and test medical devices are typically solid particles that are made from robust and stable raw materials such as polymers, glass, and in some cases, ceramics. Different types and grades of microspheres are available and selected based on specific application requirements.

    They are often used as tracers and challenge particles in medical devices. In these situations, it is beneficial to use larger microspheres with sphere diameters greater than 50 μm that are vividly colored (red, blue, black, yellow, or green), since they provide contrast with the background material and visibility to the naked eye in daylight. Colored microspheres are typically used in the testing of filtration media and systems, vial and container cleaning evaluations, flow tracing and fluid mechanics, centrifugation and sedimentation processes, pharmaceutical manufacturing, and contamination control.

    Fluorescent microspheres are recommended for applications that require the use of particles that emit distinctive colors when illuminated by UV light and offer additional sensitivity for observation through the use of microscopes, lasers, and other analytical methods. Examples include microcirculation and biological research, imaging, and flow cytometry. Fluorescent microspheres can be excited and detected by a wide range of methods and are useful as experimental particles for acoustical and optical analytical systems.

    Continue reading “Microspheres for Medical Devices – MDDI Magazine – January 2011” »

  • Density Marker Beads – Microspheres with Specific gravity of 1.065 and 1.075

    Product Announcement:

    Density Marker Beads 1.065 Specific Gravity

    Red 1.065 g/cc Spheres

    In the biomedical industry researchers are sometimes looking for cells having targeted specific gravities.  In order to locate these cells in test tubes it is useful to have colored marker beads which will show where the delineation between specific densities occurs.  Two microsphere products having densities of 1.065 g/cc and 1.075 g/cc were recently released.

    Blue Density Marker Beads with Specific Gravity of 1.075

    Blue 1.075g/cc Spheres

    These spheres are offered with density tolerances of ±0.005 g/cc enabling excellent stratification, and bright blue and red coloration for high visibility with the unaided eye.

    R&D Quantities are in stock and ready to purchase in sizes from 10um to 600um, larger 1kg+ quantities can be made to order to existing specifications or made to your custom color and density requirements. For more information visit:  Blue Density Marker Beads 1.075g/ccRed Density Marker Beads 1.065g/cc.    Additional densities of marker beads are also available in 1.01-1.10g/cc

    Some Materials which have densities close to these markers are1:

    Rat liver cells
    Hepatocytes 1.07–1.10g/ml
    Kupffer cells 1.05–1.06g/ml
    Human  blood cells
    Thrombocytes 1.04–1.06g/ml
    Lymphocytes 1.06–1.08g/ml
    Granulocytes 1.08–1.09g/ml
    Erythrocytes 1.09–1.10g/ml
    E. coli 1.13g/ml
    Viruses
    Tobacco mosaic virus 1.06g/ml
    Equine  abortion virus 1.08g/ml
    Influenza virus 1.06g/ml
    Organelles
    Mitochondria 1.09–1.11g/ml
    Lysosomes 1.04–1.11g/ml
    Peroxisomes 1.05–1.07g/ml
    Synaptosomes 1.04–1.06g/ml
    Nuclei 1.08–1.12g/ml

    Source:
    1 – Courtesy of Amersham Biosciences