We have found that most people are using it for new applications and some are looking at it as replacement for current methods,
especially because of potential cost savings. For example, the technology does not use nozzle systems. The technology also
has been helpful in some cases where there may be difficulty in scaling up a process because of over-wetting and the number
of nozzle systems that may need to be used. Foam technology has been proven to scale very easily for both immediate release
and matrix controlled-release products. The technology also uses less water per granulation, which means less drying time
and less impact on the environment.
This technology appears to help solve the issues that people have been having with wet granulation of highly water-soluble
and even very poorly water soluble drugs. These issues include areas of concentrated over wetting and over granulated products.
The technology seems to provide a better and a wider endpoint in which to granulate to even with some very difficult actives
that we work with, including natural ingredients in the nutritional supplement industry.
People have approached us who may initially have had an issue with a particular active ingredient that is water sensitive
but they still want to go with an aqueous system because of EPA (Environmental Protection Agency) concerns. Or they have issues
with distributing a very low concentration drug level—milligram or microgram per tablet—in a powder bed, which has been an
issue for years in the industry. People have used many techniques to solve the low-dose distribution issue. Foam does a good
job of solving this problem because it is a good carrier of components, not just the liquid itself and the polymer, but it
also can carry active ingredients at very low concentrations.
Q. There is interest in converting some unit operations from batch processing to continuous processing. Has continuous application
of foam granulation been explored?
A: One of the application areas we are looking into is continuous granulation using foam. Some manufacturers of continuous granulation
equipment have approached us regarding possibly working with them to use foam to deliver the liquid binder system to a continuous
manufacturing system. If you have a continuous granulation, definitely one of your key questions is whether you are getting
uniform distribution of a binder under short residence times during the process. This is one area where foam technology might
be able to provide some advantage.
Q. Are there any remaining regulatory issues or concerns with foam granulation technology?
A: We have met with and have presented this technology to the US Food and Drug Administration's Center for Drug Evaluation and
Research. They were very excited and approved the concept because they could see how this technology could resolve issues
in getting better reproducibility of granulations. They are very supportive of the technology, and they have told us that
if people come in using this technology, it would not slow down any approvals.
Q. What are the future plans for this technology? Will its applications be extended?
A: One of the things that we are continuing to develop and that we have patents for is to fine-tune the technology for coating
of tablets using foam rather than conventional spraying. We are working with equipment vendors on that. On the granulation
side, we are continuing work on using foam to distribute low-dose drugs uniformly within a powder bed or to improve content
uniformity of low-dose active pharmaceutical ingredients. We are also working with fluid-bed applications.
1. P. Sheskey et al., "Foam Technology: The Development of a Novel Technique for the Delivery of Aqueous Binder Systems in
High-Shear and Fluid-Bed Wet-Granulation Applications," poster presented at AAPS Annual Meeting and Exposition, Salt Lake
City, UT, Oct. 26-30, 2003.
2. P. Sheskey et al., "Scale-Up Trials of Foam Granulation Technology—High Shear," Pharm. Technol.
31 (4), 94–108 (2007).