Morphology Testing for Microspheres & Microneedles

Both microspheres and microneedles are used as carriers for drug delivery, and their shape and size have a bearing on the delivery of the drug. CD Formulation can receive samples from companies for morphology testing, and also offers custom product services for morphology testing of microspheres or microneedles. We will provide you with morphology testing data directly after preparation to ensure that the product is delivered to your specifications and that it is homogeneous. The current morphology analysis for microspheres and microneedles is divided into electron microscopy testing and particle size analysis.

How to Perform SEM Testing

Scanning electron microscope (SEM) is an analytical instrument that uses secondary electron and backscattered electron signals to obtain information about various physical and chemical properties of the sample under test itself, such as morphology, composition, crystal structure, electronic structure and internal electric or magnetic field, through a vacuum system, electron beam system and imaging system, with a resolution of up to nanometer level, to analyze the morphology of microspheres and microneedles.

Microsphere sample preparation process

Take the suspension of the sample after sonication with a pipette gun, put a drop on the silicon wafer or tinfoil, dry it naturally/infrared lamp, and stick the silicon wafer or tinfoil on the sample bench after drying with conductive adhesive for testing.

Microneedle preparation process

Cut microneedle strips prepared by different prescriptions, observed under microscope, and photographed and recorded, and the surface morphology of microneedles observed more clearly by scanning electron microscopy.

Service Details for Particle Size Analysis

Particle size analysis is based on Dynamic Light Scattering (DLS). A typical application of dynamic light scattering is the characterization of particles dispersed in liquids. The Brownian motion of the particles suspended in solution causes fluctuations in the light intensity of the scattered light. The fluctuations in light intensity are analyzed to obtain the velocity of the Brownian motion of the particles, and then the particle size is obtained by the Stokes-Einstein equation. DLS can be used to determine the size distribution of various particles, including polymers, and nanoparticles. If the system is not size-dispersive, the average effective diameter of the particles can be determined, as the measurement depends not only on the core size of the particles, but also on the size of the surface structure, the particle concentration and the type of ions in the medium.

Generally, particle size analysis is applied to the detection of microspheres. CD Formulation uses a high performance particle size analyzer to characterize the particle size and its distribution of microspheres by taking a suspension of microspheres in a four-walled quartz dish, setting the refractive index and viscosity of the dispersed mass and the dispersed phase for testing, and taking all the number-average distribution data for statistical analysis of the results. The particle size distribution polydispersity coefficient (PDI) is also calculated by the instrument, the smaller the PDI value, the narrower the particle size distribution.

If you have samples for morphology testing, or you need custom microspheres or microneedles, please feel free to contact us and we will provide you with professional testing services.