Office for Technology Commercialization

Drug Delivery: Shear-reversible Semi-solid Composites

Technology #20160315

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Injectable Drug DeliverySilica Nanoparticles
Chun Wang, PhD
Associate Professor, Biomedical Engineering
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Managed By
Leza Besemann
Technology Marketing Manager 612-625-8615
Kevin Nickels
Technology Licensing Officer 612-625-7289
Patent Protection

Provisional Patent Application Filed

Controlled Drug Release

New composites for drug release, include silica nanoparticles and a semisolid polymer, are more versatile than the semi-solid polymers alone in terms of accommodating and releasing multiple drugs and active molecules. They are easily injectable, allow more controlled/sustained release, allow different release profiles of a single drug (or for two different drugs from the same composition) and do not require solvents. The semi-solid composite design features shear-reversible properties:

  1. Shear thinning. The viscosity of the composite can be reduced by mechanical shear, making it easier to inject or process the material.
  2. Shear recovery. Thinned material regains its viscosity after shear stress is lifted; the material “solidifies” after injection or processing (e.g., releases a drug in a sustained manner).

Injectable Drug Delivery System

Less than half of the high potency, low solubility drugs developed ever reach the market because of inadequate excipients that cannot solubilize a sufficiently high concentration or provide stability. Meanwhile, demand for injectable drug delivery systems capable of long-term delivery with tunable release profiles has steadily risen over the last few years. Injectability and processing of semi-solid polymers for parenteral, oral or topical drug delivery can be challenging due to inherent viscosity of the polymers. These new shear-reversible, semi-solid composites can be injected or processed at shear-induced low viscosity and then "solidify" to high viscosity after injection or processing. This method does not require any solvents, diluents, heating or spray-drying.


  • Two-part formulation (polymer and silica components)
  • Shear thinning reduces viscosity, making it easier to inject or process
  • Shear recovery allows material to “solidify” after injection or processing
  • Requires no solvents
  • Allow more controlled/sustained release than hydrogels
  • Enables different release profiles of a single drug or for two different drugs from the same composition


  • Drug delivery platforms
  • Oral and parenteral drug delivery
  • Pharmaceutical excipients
  • Injections
  • 3D printing of oral tablets

Phase of Development - In-vivo testing