Monday, July 30, 2012

Rememberance

A year ago an icon of the pharmaceutical industry, the expert of filtration passed. Dr. Theodore H. Meltzer, a friend, advizer and mentor. He will always be remembered for his wealth of knowledge and humanity.

Thursday, May 24, 2012

Science versus Commercial Intentions - Example

Recently this blog discussed the issue of science versus sales, addressing the unfortunate truth that there are so called "science focused" subject matter experts with a primary, underlying ambition to increase sales for the organization they work for. A very current example shows, how such subject matter experts amend the interpretation of regulatory statements to their advantage, as well as trying to influence scientifically based positions to spin such position to the arguments used later in promotional activities.
A prime example of such behavior is the current pre-use/post-sterilization integrity test issue, which has been picked up by a major filter manufacturer to promote an integrity test system. But let's go back how it all started; EC Annex 1, paragraph 113 states that "The integrity of the sterilized filter should be verified before use...". This statement is not new, but existing since the early 90's. However, the statement became critical since a few regulators started enforcing this statement, adding confusion rather than clarity. A presentation given in 2008 at the PDA/FDA Conference pointed out that the enforcement of the statement will increase processing risks, since the sterilized downstream side requires manipulation and atmospheric pressure conditions to perform the integrity test. This was challenged by a prominent member of the mentioned major filter supplier. A task force formed by PDA analyzed multiple different filtration system designs and so far all risk assessments showed an increase in the risk probability number. The position has to be to encourage risk assessment and not thoughtless enforcement.
Coming back to the prominent "subject matter expert"; first the challenge in 2008 that the risk increase is not substantial, but then this same person tried to influence regulators and a position statement, which encourages risk assessment instead of standardizing to such pre-use test. The reason for the motivation to argue for such test just became obvious with an announcement of a webinar, promoting a test device which performs a pre-use test on single-use filter devices. Even in the webinar promotion, regulators are used to cause enforcement for the industry and statement are interpreted to the ambition of the supplier. Moreover, not just the test system is promoted, but also redundant filtration. 
Well, science versus commercial interests, this is a prime example. It is a disgrace that the industry is pushed by a vendor sales ambition into something which showed risk increase, which might not be scientifically sound and moreover into a re-design of all their processes. Vendors should support the end-user. So called subject matter expert need to stay scientific.

Monday, April 9, 2012

Pre-use/Post-sterilization integrity testing - the use of a debate for commercial purposes !

Why, one has to ask, is it that a scientific, biopharmaceutical industry topics ends up to become ones again a commercial opportunity to some ?!
Is it not bad enough for the industry to convince regulators that a) processes and activities used for decades in the industry work reliably and b) one knows what one does, i.e. leave the decisions to the end-user ? No, instead of supporting the industry with expertise and a one voice approach, scientific and/or regulatory topics become a contest by the supply industry ! The "who knows best" game is played and unscientific debates spur the fire of confusion. Moreover in instances like this, the regulatory confusion is even used as a commercialization opportunity. Purely to gain a few percentage points of increased revenue an entire industry is subjected to non-common sense regulatory demands.
When do suppliers realize that not the supplier with the highest commercial sense, but the one with the most scientific sense and support will be embraced by an industry which is scrutinized enough ?
A prime example is the current debate of the necessity of pre-use/post-sterilization integrity testing. The topic is fairly easy to resolve; leave the decision whether or not such integrity test should be performed or not to the end-user, to the industry. They perform the riosk assessment and not the supplier, they require to justify their activities to regulators and not the supplier and they have the best experience with their processes and not the supplier. The supplier should support with data, when asked for and required. This topic is not about the ability to perform such test and the great engineering abilities of suppliers, it is about the choice of the industry to either perform such test or not and what are the risks involved.
However, as usual, some suppliers think to take advantage out of a situation like this, express their unsolicited opinion and cause more problem for the industry than good.
Time to stop this nonsense and rather put science in front of commerical motivations !

Sunday, April 1, 2012

Are sterilizing grade filters commodities ?

Sterilizing grade filters are once in awhile perceived a commodity item, especially by procurement departments, not realizing that this is far from truth. Technical departments choosing the right or better optimal sterilizing grade filter for a specific application understand the importance of the utilization of the optimal filter. If the filter is is chosen by pricing instead of performance, the actual costs is far higher than the savings of the price of a filter. Filter performance is not only measured by its retentivity, which is a required must anyway, but also by proper sizing, unspecific adsorption, premature fouling, thermal and mechanical stability etc. If he filter system is improperly sized, the hold-up volume will result in major product losses. Tests in unspecific adsorption showed potential losses of hundreds of thousands of dollars of product on the membrane surface. Sterilizing grade filters testing is of importance to find the optimally balanced filter for the specific application, then the procurement department can negotiate pricing, but should fully understand that the optimally balanced filter will safe far more money than a 20% discount.

Monday, March 5, 2012

"Absolute" retention - A necessary debate ?

Unfortunately the 80s are still with us and there are still believers of "absolute" retention, in instances even for prefilters. There are statements of such and such filter with "absolute" retention, retention rating or the "absolute" retention is justified by the mythical beta-value (not so mythical and extra ordinary in process engineering calculations of sieves and porous loads). Moreover, not that such statements are pretty unscientific, but there are some who argue the case of "absolute" retention or retention rating.
Well is that debate necessary ? No, absolutely not.
In reliable filtration, whether depth-, pre- or membrane filtration one has to determine the performance of the filter within the particular application; under the process conditions the specified contaminants requires to be separated to pre-defined levels. So no matter what "absolute" rating is given, it is unimportant as the performance needs to be tested under the process conditions of the particular application. Only then the real retentivity is determined, only then one can reliably say that the filter's retention rating holds what it promises. Retention rating labels are useful guidances to chose certain filter types, but ones chosen the retention performance needs to be verified, as filters can act differently under different process conditions, fluid streams and contaminants. The separation mechanisms of sieve and absorptive retention need to be checked for their effectiveness, are these still act in a sufficient way under the particular process conditions, fluid streams and contamination types. Process validation of filters is the most necessary action to gain a reliable filtration process.
"Absolute" filtration is obsolete, therefore an unnecessary debate or better expressed by Dr. Cooney "It should solely be used for vodka". I agree.

Sunday, January 29, 2012

Is integrity testing reliable ?

The quick answer is yes, when performed with an automated integrity test system and truly it does not matter of which particular brand, when used correctly and according to the manufacturer. The brands compete against each other, often claim a better test method and highest sensitivity, but well physics is what it is, you cannot twist it or make one part of it better than the other.
Anyway, back to integrity testing reliability. Integrity testing has developed over the last 20 years to a state of the art refined technology, with high accuracy and robustness. Testing especially sterilizing grade filters is of utmost importance to verify that these filters have not been damaged during use. So the test machine, but also the method and end-user training requires to be robust to achieve the reliable test results. The test should not be rushed, as it once in awhile happens, because saving test time, seems to be more important than a precise outcome, besides a failed test will cost by far more than time. There should be no shortcuts when it comes to appropriate wetting of the filter, training of staff, proper test gases and temperature conditions etc. When the test is properly qualified and performed, reliability of the test does not need to be in doubt.
Having said this an integrity test does not replace process validation of a filter. Process validation including product/process related bacteria challenge testing is the only option to verify that the filter is retentive within the process conditions filtering the defined fluid.
Integrity testing does not replace the necessity of the challenge effort. The integrity test is there to test the validated filter, i.e. the state of that filter in that validated process. Nothing more, nothing less.