Solid dose production typically starts with the formation of the drug into particles which range in size from 0.1 to 101¼m. It is often important to characterise these particles as their size and shape can provide useful information on the manufacturing process. Particle size has also been shown to influence dissolution rate, content uniformity and sedimentation rates.
The next stage of the pharmaceutical manufacturing process is often to form the particles into a granule by using a binding agent. The resulting granules are typically in the range of a few millimetres and show improvements in flow properties. It is useful to characterise the roughness of granules to correlate this with the manufacturing processes. The final element in tablet manufacture often entails applying a coating to the granules which can serve a variety of functions, including protecting the drug from air and controlling dissolution behaviour. It is often a requirement in tablet manufacture to correlate the surface characteristics of their coatings to their dissolution rate.
There are a wide range of requirements for surface characterisation within the pharmaceutical manufacturing arena. One of the more important is in ensuring that the surface finish of pipes and dies in the process area are of a suitable quality to minimise bacterial contamination. Pipes used in pharmaceutical plants can be made from stainless steel or plastic and they can have a range of surface finishes, from 21¼m to 0.21¼m Rq. The surface finish of these pipes is critical when one considers that a common bacteria cell like pseudomonas aeruginosa, which is rod shape can be approximately 0.3 to 0.81¼m wide and 1 to 1.21¼m microns long. Poor surface finish on these pipes could allow for bacteria to build up and would contaminate the manufacturing process. For product information click the link below.