What can it be used for?
Preparing flawless samples.
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Most textbooks on different measurement techniques describe the uniformity with defined geometries as the key to determining accurate material properties. The VCM technology was originally developed for preparing samples for rheological measurements.
Rheology (Discs 8-25 mm & Bars 10x40 mm)
When studying flow behavior, samples are deformed within defined measuring geometries and characteristic material properties are derived. When bubbles are present, the flow field is distorted and the measurement falsified.
Homogenous
vs.
Bubbles
Homogenous
vs.
Bubbles
Early rupture
Extensional rheology requires homogeneous bars to obtain results. No sample preparation starting from powders existed so far. VCM opens the opportunity for the first time. New insights help to understand material and processing behaviors.
Our customers use the flawless VCM samples for various measurement methods such as DSC, hardness, notch impact strength, heat capacity, solubility, DMTA, microscopy etc. Below is a short excerpt of one of the most frequently requested measurement methods.
What else?
Surpassing your expectations.
DSC Measurements (Discs 5 mm)
Samples are placed in a crucible and subjected to a controlled heat transfer cycle. Particle boundaries hinder heat transfer. Homogeneous VCM samples ensure uniform heat transfer and will lead to more significant results.
Heating Unit
Powder
VCM sample
1st
heating
1st
heating
DSC
crucible
Phase
Boundaries
Homogeneous
Vacuum Unit
Moreover, thermal conductivity and heat capacity can be derived via a mathematical model from modulated DSC measurements on two samples with different thicknesses. Both values can be derived from sample quantities lower than 100 mg of material.
0.4 mm
3 mm
What about prototyping?
Nothing easier than that.
Pilot plants and six-digit Euro investments were required for prototyping of pharmaceutical dosage forms with melt-processed carriers in the past. Now, the VCM technology enables rapid prototyping at a fraction of costs and time required for traditional prototyping methods.
Dissolution (Discs 5-25 mm)
MeltPrep samples can be used for intrinsic dissolution testing giving valuable insights into formulations characteristics. The samples have defined geometries and release the drug via a defined surface, thus specific drug release properties can be derived from testing. Optional cups can be used to enable unilateral testing.
Heating Unit
Noyes-Whitney equation
Intrinsic dissolution rate
Vacuum Unit
Cup
Sample
Dissolution
vessel
Spectroscopy (Discs 25 mm)
MeltPrep has developed dedicated easy-to-use offline solutions for combining the VCM Tools with common process sensors to analyze molten samples offline. The results can be used for designing the probe position for inline implementation.
Is that all?
Not even close.
The VCM Technology enables the production of multilayer samples. Layers of different materials are prepared one by one. Subsequently, the layers are stacked in the desired order and loaded into the VCM Tool. By performing an additional VCM cycle they are fused to one solid multilayer sample
Diffusion Studies (Discs 8-25 mm)
Multilayer samples are requested in galenics to study drug diffusion and release. They are also used for controlled release drugs. A well-known example is the intra-vaginal birth control ring (IVR) from Merck (NuvaRing™).
Heating Unit
Drug loaded core
Diffusion barrier
100 pm
4 mm
Diffusion barrier
100 pm
Lateral surface
sealed with
barrier glue
e.g. Ø10 mm
Vacuum Unit
Cross
section
IVR e.g. Ø 50 mm
Drug loaded core
Diffusion barrier
Eder et al. (2017)
VCM preparation < 1 day
vs.
Conventional co-extrusion > weeks
Similar results
at a fraction of the
cost and time
Standard dissolution testing and surface corrections lead to similar results. In many cases there is no need for executing pilot scale experiments.
