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Encapsulation / Microencapsulation Services

Encapsulation  Microencapsulation Services
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Encapsulation  Microencapsulation Services
  With expertise in research and development for a variety of encapsulating substrates, AVEKA serves industries ranging from consumer goods and alternative energy, pet care, medical device, and manufacturing sectors. Our encapsulation and microencapsulation methods include alignate encapsulation, polyoxymethylene urea microencapsulation, and complex coacervation (gelatin) microencapsulation, with each technique offering unique and specific advantages dependent on factors such as bead formation, release mechanism, active and core materials. Our encapsulating substrate research and development specialties include solid and liquid, water soluble or hydrophobic, controlled gradual or sudden release, substrates tied to a pH, temperature and/or other physical or chemical change. We're happy to provide contract and continuous manufacturing, as well as consulting, innovation and IP development, and other services. To learn how AVEKA can assist in your next encapsulation or microencapsulation project, please see below and contact us today.
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Encapsulation / Microencapsulation Services Specifications:

General Capabilities Contract Manufacturing
Continuous Manufacturing
Toll Processing
Research And Development
Innovation and IP Development
Industry Focus Consumer Goods
Alternative Energy
Personal Care
Medical Device
Pet Care
Industry Standards ISO - 9001 - 2008
International Organization for Standardization
Alginate Encapsulation This encapsulation technique is traditionally used to produce relatively soft spheres of alginate, a natural polymer extracted from seaweed.  Oils of all kinds can be incorporated into the alginate beads at loadings of up to about 70 weight percent (wt %), including oils for personal care items (e.g., Jojoba oil), specialty foods (e.g., olive oil), fragrances, and nutritional supplements (e.g., marine liver oils, garlic oil). Since alginate is approved for food, cosmetic, and pharmaceutical uses, it is well suited for a broad range of applications.  Most alginate beads are matrix-type capsules, that is, they hold the fill material throughout the bead, rather than having a distinct shell as in a core-shell type capsule; however, alginate can also be used to make a core-shell bead using a new patent-pending process.

Soft Alginate Beads

Typical Fill Materials
Hydrophobic liquids, such as mineral oil, fragrance oils, and edible oils; solid particulate material and powders; skin emollients and hair conditioners; sun screens; pigments.

Release Mechanism
Soft Alginate capsules are broken by pressure, typically that amount generated by a gentle squeeze between thumb and forefinger. The beads can be made soft enough to fall apart easily or tough enough to withstand specific chemical and thermal environments.

Alginate soft beads are a matrix type capsule. For liquids, the percentage fill, or payload, is typically between 20 to 60 weight %, although on some oils the fill may be lower or higher. Bead size can presently be varied between about 100 microns and 4.5 mm; processes under development promise to push the lower size limit to about 10 microns.

Present Production Capacity
AVEKA has developed an innovative production process to produce hard beads faster than traditional drip methods.

Advantages of Alginate Microencapsulation
The soft alginate technique is well established and produces edible capsules with easy release by pressure and little remaining wall material after breakage. It is ideal for carrying hydrophobic liquids (i.e., oils), and is called for when capsules must be very soft, food or cosmetic grade.

Dry Alginate Beads (Starch Beads and More)
Solid powders and pigments, such as titania, zirconia or starch, can also be incorporated in the wet beads at loadings of up to 95-99%.  By drying these beads under controlled conditions, a hard bead is obtained.

To make a starch bead, 1-3 wt % alginate is mixed with unhydrolyzed starch granules and then dried.  Since the starch is in a granule form, the resulting starch bead has up to 30 volume % porosity.  In use, the beads may be soaked in a liquid active to imbibe the liquid.  The release of the active is by diffusion. Starch beads are handy, environmentally safe carriers and deliverers of fragrances, typically used in the air freshener and potpourri market. Usual sizes of the dry white or pigmented bead range from 2-5 mm.

Typical Active Materials
Hydrophobic liquids, such as fragrance oils; and pigments. In starch beads, fragrance oils can be loaded to 30 %.

Release Mechanism
The hard alginate beads release their fragrance gradually over time.

For the hard beads, the titania or zirconia is 92-98 wt % of the bead, while starch is 97-99+ wt % of the bead.

Present Production Capacity
We are currently ramping up the production levels for the hard beads.

Advantages of Alginate Microencapsulation
The hard alginate beads are excellent for delivering fragrances, for agglomeration of dry powders into spherical beads, or for carrying dry materials into water-based systems.
Polyoxymethylene Urea Microencapsulation The PMU encapsulation technique, also known as urea-formaldehyde, can be used to deposit a tough polymer coating on drops of oils or other hydrophobic liquids, as well as some solids or powdered material. The technique is widely used for encapsulation of fragrances and cosmetic oils. PMU encapsulation is an emulsion technique, where the material to be encapsulated is first emulsified in a water solution and then the shell is deposited on the droplet. Hence the core (fill) material must be insoluble in and non-reactive with water.

Typical Core Materials
Hydrophobic liquids, such as mineral oil and fragrance oils, are often encapsulated with PMU. Any liquid with negligible miscibility in water, reasonable viscosity, and a pH near neutral can in principle be used as a core with this method. In addition, some solid particulate material can be encapsulated with PMU, as long as it is stable in water at low (acidic) pH values.

Wall Material
The wall material is derived from co-polymer of urea and formaldehyde. While formaldehyde is used in the process, the amount of free formaldehyde remaining after the capsules have been made and dried is extremely small (less than 100 ppm is typical).

Release Mechanism
The core material is constantly released slowly by diffusion and releases in a burst when the capsules are broken by pressure. They may be broken by squeezing between thumb and finger or by scratching PMU capsules that have been printed on a page, as in scratch and sniff applications.

PMU capsules are true core shell type microcapsules. For liquids, the fill or payload can reach up to 80% or more, depending on the material. Capsule size can presently be varied between 10 and 120 microns; larger sizes may be accommodated for some materials.

Present Production Capacity
PMU encapsulation is a batch process, with present capacity at about 25 kg of capsules/batch. The process is being scaled up to attain about 100 kg per batch.

Advantages of PMU Microencapsulation 
The PMU technique is a well-established technique that produces durable capsules with good retention of volatile components. PMU is approved for use in cosmetics. It is ideal for hydrophobic liquids (i.e., oils), and is called for when capsules must be very small (below 20 microns), thermally stable, and have insoluble walls.

Dry Water
Dry Water is an innovative way to deliver water-soluble active ingredients to the skin and hair using a patented AVEKA method. The beads form a dry free-flowing powder that liquefies upon gentle rubbing.

Typical Core Materials
Water that may contain additives such as fragrances and other water soluble and water dispersible materials.

Wall Material
Hydrophobic fumed silica

Release Mechanism
Gentle rubbing

Core-shell capsules range from 20-200 microns in diameter. The current beads are stable, but fairly fragile and will not maintain their integrity if frozen.

Present Production Capacity
At least 250 kg per day

Advantages of Dry Water
Dry Water make a dry flowable powder that carries liquid water. The beads may be used to carry hydrophilic fragrances and actives for release in personal care products when the beads are rubbed in the hands. The release of the liquid also provides a cooling affect.
Complex Coacervation (Gelatin) Microencapsulation The complex coacervation encapsulation technique uses coating materials derived from natural plant and animal sources. Gelatin is derived from either pork or bovine sources, and although it surprises some people, Kosher gelatin is available. The other component of complex coacervation microencapsulation is often acacia, also known as gum acacia or gum arabic, which is made from the bark of several species of acacia trees. Microencapsulation via gelatin and/or gelatin-acacia is an emulsion technique, where the material to be encapsulated is emulsified in a water solution. Hence the fill material must be insoluble in and non-reactive with water. The technique is often used to encapsulate oils and other hydrophobic liquids for use in food and pharmaceuticals.

Typical Core Materials
Any liquid with negligible miscibility in water, reasonable viscosity, and pH between 4 and 8 can in principle be used as a core with this method. Hydrophobic liquids, such as edible oils and flavorings, are frequently used. Also, solid particles and powders can be encapsulated in gelatin-acacia capsules.

Wall Material
The wall material for complex coacervation is derived from co-polymer of the natural polymers gelatin and acacia. Gelatin alone has also been used. Walls are insoluble in water, and can be made thicker or thinner to control the core release rate. If the walls are cross linked, they become much tougher and less leaky.

Release Mechanism
Gelatin-acacia capsules are broken by pressure or mechanical forces, such as chewing, and by digestion.

Gelatin-acacia capsules are a true core-shell type microcapsule. For liquids, the fill or payload, can reach up to 90% or more, depending on the material. Capsule size can presently be varied between 20 and 300 microns; larger sizes may be accommodated for some materials.

Present Production Capacity 
Gelatin-acacia encapsulation is a batch process, with present batch capacity at about 4 kg of capsules. The process is being scaled up to attain about 50 kg per batch.

Advantages of Gelatin-Acacia Microencapsulation
The gelatin-acacia technique is a well established technique and produces food grade capsules with stable, digestible or chewable walls. It is ideal for applications calling for hydrophobic liquids (i.e., oils), small capsules (below 20 microns), and edible materials.
GEL Beads GEL Bead will deliver up to 95% oil without unwanted residue. This patent-pending, "no shell" technology allows liquids to be transformed into a soft gel bead with oil loads previously impossible to manufacture. They can deliver oils and miscible actives including ingredients such as tocopherol (Vitamin E) and Vitamin K. They can also be designed to deliver a heating effect. Unlike most beads, GEL Beads can be easily rubbed out with virtually no residue! GEL Beads can be suspended in oils or in aqueous formulation for skin care, hair care, and other applications. It is possible to deliver actives and create a unique visual appeal using GEL Beads.

GEL Beads are a colored or pearlescent bead used to deliver oil and active ingredients to the skin or hair without unwanted residue. The standard formulation utilizes 89% soybean oil. Custom colors, oils, and formulations are available upon request.

Example Formulation:

Glycine Soja (Soybean) Oil,Polyethylene, BHT, Pigment
Percent Oil: 89%
Bead Size: 400 - 1000 microns

GEL Beads are packaged in water in one (4 lbs) or five (20 lbs) gallon containers.Custom packed sizes can be evaluated.

Store in a cool, dry area, preferably less than 85 degrees F and less than 60% relative humidity. Under these conditions, shelf life of unopened containers should be a minimum of one year. Retesting may be recommended if ambient conditions exceed above.

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