Surface finish for reactor to produce API's

[Bartolo]

Does anybody has experience with different internal surface finishes of reactors that produce active pharmaceutical ingredients, and their relationship with cleanability?
I know that for the pharmaceutical industry there are standards that say that the Ra-value should not be higher than 0.8µm, but for the production of API's no such standards or guidelines exist.

 

[HEC]

Bartolo,

You have not mentioned what API is being produced or the steps required in production. I presume that it is also for Bulk Pharmaceutical. These are items to consider in determination of the surface finish requirements.In general cleanability, and bio contamination requirements need to be considered to determine the surface finish specification.

Specification of the Ra value only can yield unexpected performance. The method of obtaining a surface finish can also affect the final operating character of a surface. As an example to compare mechanical polishing and electropolishing. Mechanical polishing can provide very low Ra values, approaching mirror finish, however this is achieved by rolling peaks over which can create minute enclosed pockets. Compared to electropolishing that removes the peaks to provide a mirror finish. These two visually and stylus surface finishes will perform diferently depending upon the operating conditions.

In summary more must be known about the process and requirements before a recomendation on material surface finish can be made.

Mark Hutton
hutton4eng@picknowl.com.au

 

[Bartolo]

Mark,

Thanks for your response. The problem that I am facing at this moment is that there does not exist a standard for specifying the surface finish for multipurpose reactors producing API's. Being a producer of API's we have to comply with the ICH Q7A guidelines. However within these guidelines no requirements are stipulated about the surface finish of product contact materials. We only have to prove that the surfaces can be cleaned in a sufficient way. That is why I am wondering if anybody has experience with the selection of surface finishes within this type of industry.

 

[HEC]

Bartolo,

As I stated in my response, the nature of the process, actives, particle size etc will influence the cleanability of a surface. If you do not want to discuss the actives etc in a public forum perhaps you should email me directly.

Mark Hutton
hutton4eng@picknowl.com.au