Residual Metals and Metal Catalysts

In 2008, The European Medicines Agency (EMEA) set forth a guideline regarding the presence and amount of various metals as impurities in pharmaceuticals (EMEA 2008: Guideline on the Specification Limits for Residues of Metal Catalysts or Metal Reagents). The following is an overview of the guideline and options for setting the concentration limit for a metal residue.

The metals were classified by level of concern. Metals of significant safety concern are: Class 1A: Pt and Pd; Class 1B: Ir, Rh, Ru, Os; and Class 1C: Mo, Ni, Cr and V. Metals regarded as of  low safety concern are in Class 2 and include Cu and Mn. Finally, metals with minimal safety concern are Fe and Zn and are in Class 3.

The following chart shows the PDE for each of these metals and how the numbers vary with regard to the route of exposure:

(Click to enlarge)

Two options are available for setting a concentration limit for a metal residue. In the first option, the concentration limit in ppm as stated in the table can be used, as long as the total daily dose of the drug product does not exceed ten grams per day. If it exceeds 10 grams per day, then one must pursue the second option, the PDE. The amount stated in the table can be used in conjunction with the exact total daily dose of material in the drug product to calculate the permissible concentration of residual metal allowed. If using the second option it is not necessary to be in compliance with the limits stated in the first option.

For pharmaceutical products administered via other routes than those stated in the table, the concentration limits need to be set in consideration of the route of administration. Unless there is documented justification, parenteral limits or PDEs need to be used  for pharmaceutical substances that are administered by other routes, including inhalation.  Limits or PDEs via an oral route can be used if the absorption by other routes of administration are not likely to exceed the levels observed with oral administration.

For pharmaceutical products used in short-term or life-saving indications, higher PDE values may be acceptable in cases of short-term use (<30d), since the values in the table are based on the assumption of chronic use. Justifications to the agency are presented on a case-by-case basis.

>> Calvert Labs can help you with the resolution of any issues with regard to the presence of residual metals that you may be experiencing with your pharmaceutical substance.

Contact us today if you need assistance.

Written by Thomas Ferrell, B.S., RLATG
Manager, Laboratory Animal Resources & Primatologist
The use of non-human primates in biomedical research is a continually evolving process. With the advent of translational research the importance of genetic definition appears to be coming to the fore front.
At present, the most commonly used non-human primate models are the Cynomolgus macaque  (Macaca fascicularis) and the Rhesus macaque (Macaca mulatta). The Rhesus genome has been completed and basically reveals two distinct populations, India and China. For an example, Rhesus macaques from India, rather than China are currently the preferred model for AIDS research because they exhibit several genes shown to influence disease progression. India banned all export of Rhesus macaques in the mid-1970’s and as a result, animals brought in prior to the ban and their descendants have become very valuable as breeding stock.

The mapping of the Cynomolgus genome is in progress and preliminary results show distinct regional populations throughout Indochina and the islands (Philippines, Indonesia, Mauritius). Animals originating from various regional populations have already been mixed in captive breeding colonies resulting in hybrid animals. Recently in the Indonesian Cynomolgus, a cDNA sequence in the binding domain of a gene has been identified that they share exclusively and surprisingly with India origin Rhesus. Anecdotally, Vietnam origin Cynomolgus, weight for age tend to be smaller where Mauritius origin Cynos, weight for age tend to be the largest thus having a direct effect on the amount of test article required for a given study. As there is really no indigenous population of Cynos in China, Cynos of Chinese origin tend to be hybrid animals. Much work remains to be done to elucidate the differences in Cynomolgus monkeys from various regions.
The inadvertent inclusion of macaques from different geographic regions or their hybrids into experimental groups can foster results that are ambiguous due to the differences in physiological, phenotypic and behavioral traits that are controlled by genetic mechanisms.
Calvert always has and will continue to monitor and source match all experimental macaque groups in an effort to avoid adding unwanted experimental variables during the conduct of toxicology studies.

Written by Laurie Serfilippi, Director of Laboratory Animal Medicine at Calvert Labs

Swine have been used in biomedical research for decades.  With the development of small breeds of swine, mini-swine, the pig has become a more accepted model in toxicology testing.  The FDA has indicated that the mini-swine is considered to be the model of choice for dermal toxicity testing.  Pig skin is very similar to human skin in anatomy as well as how it reacts to substances administered topically.  Anatomically the stratum corneum in pig skin (20 microns) is very similar to human skin (10 – 20 microns) while the other species commonly used for dermal toxicity have a thinner stratum corneum.  This layer acts as a barrier to topically applied substances and using a model with a similar barrier layer is a more accurate indicator of the type of local and systemic toxicity that can be expected in the human.

Other similarities between pig skin and human skin are pH, cutaneous blood supply, tight attachment of the skin to the subcutaneous tissues, lipid biophysical properties, epidermal turnover kinetics, and carbohydrate metabolism in the skin.  Many of these properties make the pig an excellent model for transdermal drug delivery systems.

The pig like the human is relatively hairless which makes preparation of the application site easier.  There is less chance of causing abrasions when the small amount of hair is removed. There are breeds of mini-swine such as the Göttingen and Hanford that are white which allows for accurate determination of dermal irritation.

Some of the differences between pig skin and human skin are a lack of apocrine sweat glands in pig skin and the amount of subcutaneous fat deposition as the pig ages compared to humans.

Some of the species specific considerations of using swine in dermal toxicology as well as toxicology testing in general are as follows:  When a dermal product is applied to a pig’s back it can not turn around and lick it off but pigs are great at rubbing on the sides of the cage so there is the potential to rub it off.  If toxicokinetic blood samples are required after a pig has been dosed topically there is the problem of having to collect the blood samples from the pig without disturbing the application site since blood collection is performed in mini-swine using a V-trough on their backs.  Swine are not an easy species to deal with when it comes to manipulations.  They resent most procedures that require restraint or momentary discomfort.  It takes time and effort to train them to accept most procedures so acclimation times are longer and the number of technicians that are dedicated to working with the pigs is greater to allow for training.  If adequate time and training are allowed pigs can become quite used to and acceptable to the preparation of the dermal application site and the application of the dermal compound.

Calvert offers toxicology studies using the Göttingen mini-pig.  The Göttingen mini-pig is the smallest of the mini-swine and is white, which is ideal to dermal toxicity testing.  Its size and slower growth rate allow for easier handling and conservation of test article when compared to some of the other breeds of mini-swine.

Below is the list of our upcoming conferences for 2010 and 2011.

If you plan on attending or would like to know more, contact Leslie Maas at 570.586.2411 or leslie.maas@calvertlabs.com. We would love to schedule a time to meet with you!
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Safety Pharmacology Society Meeting 2010
Boston, MA
September 20-23, 2010
Booth #203
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ACT 31st Annual Meeting
Baltimore Marriott Waterfront Hotel
Baltimore, MD
November 7 – 10, 2010
(Booth # will be posted soon)

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AAPS 2010
New Orleans Morial Convention Center, New Orleans, LA
November 14–18, 2010
Booth #821
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ToxExpo 2011
Walter E. Washington Convention Center
1207 9th Street Northwest Washington, DC
March 7–9, 2011
Booth #301
(Calvert will also be sponsoring the Golf Putting Station on Tuesday evening during the ToxExpo 50th Anniversary Celebration)

In 1999, the U.S. Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) recommended the mouse LLNA as a valid test method to assess the skin sensitization potential of most types of substances.  Regulatory agencies around the world now commonly accept the LLNA.

It has several advantages over the traditional guinea pig assays (the Buehler assay and the Guinea Pig Maximization Test).  First of all, the LLNA is run in mice which are lower on the phylogenetic ladder than guinea pigs and it uses fewer animals, which fulfill two of the animal welfare requirements (refinement and reduction).  Also adjuvant is not required which reduces the pain and distress for the animals, colored products do not mask the results, and the results are quantitative and are obtained within a week.

In 2007 concern was raised about the use of the LLNA with formulated products (mixtures) which had not been considered in the original evaluation.  ICCVAM convened an independent scientific peer review panel to review the use of the LLNA with mixtures and aqueous solution.  In June of 2009 the panel made the recommendation that the LLNA was suitable for use with these types of materials.

The use of radioactivity in some cases can be an issue.  Therefore, the peer review panel also evaluated 3 non-radioactive modified versions of the LLNA.  Two of the assays, the LLNA:DA and the LLNA:BrdU-ELISA were found to be acceptable with certain limitations.  The committee, however, concluded that the third assay, the LLNA:BrdU-FC, needed further evaluation since the results that were presented were only from one lab.  An interlaboratory validation study is needed.

The committee also evaluated a reduced local lymph node assay (rLLNA).  When appropriate, this method can reduce the number of animals used for each test by 40% compared to the traditional LLNA.  The rLLNA was found acceptable for use in hazard identification of skin-sensitizing materials if dose-response information is not needed.  It can also be used as an initial screen to determine the sensitizing potential of a material before conducting the traditional LLNA.  The only difference between the rLLNA and the traditional LLNA is that for the rLLNA only 1 dose of the test material is used.  The concentration should be the highest achievable concentration that does not cause overt systemic toxicity and/or excessive local irritation.  When used as a screen, if the results are negative, no further testing is required.  However, if the results are positive, the traditional LLNA should be conducted.

Calvert Laboratories has over 15 years of experience with the LLNA.  Our standard protocol follows the ICCVAM recommendation and all regulatory guidelines.  Contact Dr. Joan M. Chapdelaine at joan.chapdelaine@calvertlabs.com to discuss your next sensitization study.

We’ve grown accustomed to receiving real-time information. Many of us get breaking news stories instantaneously on our phones.

When we need to know our bank balances and which items have cleared or want to transfer funds–we go to our phones or computers for instantaneous information.

We expect access to information.  We expect effective, timely communication. That’s our normal lives today. And at Calvert Labs, we’re working to make it normal in our communication with you.

Coming March 2010—We are in the process of building a secure, near real-time, info-on-demand area of our website which will provide each client private access to info such as study schedules, study progression notifications, lab certifications, inspection information, and more. In addition, clients will be able to download an iPhone application which provides 24/7, secure, mobile access to their data.

What if it’s 11PM—or the weekend—and you need access to the most recent information on your study?  What are you going to do?  With most companies you will wait until the next business day. If you are a client of Calvert, you’re going log in and find that information. You will be able to download the App from the Apple store for free, use our secure name/password protection to access your account, and view your current study information whenever/where ever it’s convenient for you. Your App’s icon will indicate that there have been updates to your study so you will know that new information is available.

These new additions will further enable us to improve communication and become more responsive to our clients’ needs. Contact us today to learn how your life can be better at Calvert.

Our new data collection system will provide our clients with a greater degree of flexibility in study design, defined measurements, and ultimately in reporting. Other benefits include: statistical analysis integrated into data reports, greater variety of report formats, and a reduction in time needed to complete study reports.

The Xybion Pristima™ system provides our clients with a greater degree of flexibility in study design, defined measurements, and ultimately in reporting.  Xybion provides continuous product and service improvements as well as excellent technical support.  There is also an independent User Group run by the client community which meets yearly to discuss the system, present issues and make recommendations about the the system to Xybion.  Quality Assurance auditors from the User Group perform independent audits of Xybion and the system for FDA GLP and Part 11 compliance and report their findings to Xybion.

There are several features which can improve overall study quality. Among the features:

• More efficient data entry such as manual entry with minimal screen changes, keystrokes and mouse clicks.
• Interfaced data collection for body weights, feeder weights, and any other type of data that could be recorded via an interfaced device such as a balance, barcode reader or clinical pathology instruments.
• Checks to minimize technical errors, including visual matches of an animals group assignment to a designated color, scanning of barcode on dosing vessel prior to start of each group to verify that the correct test article concentration is being used, and scanning of barcode on sample tubes to verify that the correct tube is being filled.
• Master and study lexicons result in consistent and accurate use of measurement terminology.
• Seamless tracking of clinical pathology samples from collection in the animal room, to receipt in the clinical pathology lab, to analysis by the clinical pathology instrumentation with direct data transfer from the instrumentation to the Pristima system.
• Statistical analysis integrated into data reports. If a statistical evaluation is requested that is outside our normal procedure, a specific statistical decision tree can be created from an existing dictionary of statistical tests and incorporated into each individual report.
• Data Reports are available in a variety of formats (PDF, Word, Excel, HTML, CSV, text)

We will also now have the ability to record data for teratology/reproductive toxicology studies on-line and easily generate data tables.  Previously, the majority of data we collected for these studies was generated on paper and then manually tabulated, followed by 100% QC check of all the data points to ensure the accuracy of the transcription. With online data collection and table generation, there will be a reduction in time needed to complete study reports.

About Xybion Medical Systems
Since 1977, Xybion has been the enterprise system partner of choice for life science product companies and scientific research organizations worldwide. In addition to Pristima, Xybion provides professional services, consulting, training, and validation activities to clients around the world.

Calvert’s commitment to quality, customer service, and flexibility is now extended even further with the addition of intravenous continuous infusion as part of our parenteral route of administration.

Intravenous continuous infusion is commonly used in the clinical administration of drugs such as chemotherapeutics, antibiotics, etc..  When a compound needs to be delivered by continuous infusion clinically, using intravenous continuous infusion as the preclinical route of administration is required to mimic future clinical trials.

To perform the procedure, animals are surgically implanted with in-dwelling catheters. Each animal on study requires an infusion setup consisting of a harness (which the animal wears to connect the catheter to the infusion setup), a tether that connects the infusion line to the harness and protects the infusion line from the animal, and a swivel which allows the animal to move relatively freely within the cage.  These items are all purchased for each individual animal on a study by study basis. Calibrated infusion pumps are then used to control the rate of dose administration to each animal over prolonged periods of time.

When Calvert first considered adopting the continuous infusion procedure, the technology with the catheter implantations, infusion pumps and infusion setups was not as advanced as it is today. The improvements in technology have lead to an overall reduction in the number of technicians required to perform each study.  This now allows us to focus more time on the individual study and communication with our clients.

By now offering continuous infusion, clients requiring this service can now have now get access to Calvert’s commitment to quality, customer service and excellent reputation in the industry, and to benefits that they may not get elsewhere.

Join the Calvert Labs team at our west coast conventions this fall:

30th Annual Meeting of the American College of Toxicology
Palm  Springs Convention Center
November 1-4, 2009
Booth #202

2009 AAPS Annual Meeting and Exposition
Los Angeles Convention Center
November 9-11, 2009
Booth #432

Planning to attend? Let us know. Contact Jeff Tippett at 919-854-4453 or jeff.tippett@calvertholdings.com. We would love to schedule a time to meet with you!