Progress 09/01/09 to 08/31/11
Outputs
OUTPUTS: Multiple projects were undertaken as part of this project and all remain in various stages of completion. All project studies fell within the general mission of the NRSP-7 program to develop supportive data and otherwise facilitate regulatory approval of new and useful drugs suitable and safe for use in minor food animal species. The projects included the following: Lasalocid for Treatment of Coccidiosis in Pheasants (ADR#279)- This pending project is a collaborative effort between the North-Central and Southern Region. The primary role of the Southern region is to carry out drug analyses of all tissue samples. Previous attempts to bridge the approved regulatory method for lasalocid analysis in bovine liver were unsuccessful, which led to the failure of a human food safety trial. We have now solved all of the analytical problems and have a robust and reliable working method. That method has undergone a partial validation in pheasant tissues and is currently undergoing review by ONADE. Pending CVM final review and concurrence (expected Nov. 2012) with the study protocol and the analytical method, this project will be in position to move forward with the in-life phase studies in the North-Central Region. The anticipated time line for project start up is October of 2012. Ivermectin Medicated Feed Block for Control of Cattle Fever Tick in South Texas (ADR#352) - Preliminary work has continued slowly on this project. The study represents a minor use in a major food animal species and is a collaborative effort among several agencies and institutions, including the North-Central Region and Southern Region as well as USDA-ARS and APHIS. The project has not yet received concurrence from the CVM and it is unclear whether it will proceed or be completed. The primary role of the Southern Region is to conduct analytical testing of ivermectin levels in medicated feed blocks, which will be used for drug delivery to cattle in pastures, contain a complex mixture of nutrients, minerals and numerous other ingredients, including molasses as a taste enhancer. We have been successful in adapting the approved regulatory method for ivermectin analysis in order to determine drug levels in the feed blocks. At this time, we have completed analysis of five batches of medicated blocks, each containing 16 to 24 individual blocks. Work is currently in progress as we continue to analyze medicated blocks for consistency of drug levels. Fenbendazole in Game Birds (ADR#280) - This is a collaborative project among the North-Central, Western and Southern regions. The Southern Region has no principal role related to in-life studies (North-Central Region) nor the analytical phase (Western Region), so any final technical updates will be contained in those regional reports. Update on Other Programmatic Efforts and Changes: NRSP-7 Website: The Southern Region is responsible for maintaining and updating the NRSP-7 website, including MUMsRx and the RUSTi system for tracking the status of regional projects. In addition, the Southern Region coordinator organizes and coordinates monthly teleconferences among the regional coordinators and administrators. PARTICIPANTS: Individuals at the Southern Region of Nrsp-7 who contributed to this project were: 1) Dr. Thomas W. Vickroy, Principal Investigator and Regional Drug Coordinator for the Southern Region and 2) Mr. Kacy Magee, B.S., Analayst and GLP Studies Coordinator. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The major result that contributed to a programmatic outcome/impact was the validation and bridging of an analytical method for lasalocid residue analysis in liver and skin of ring-necked pheasants. The approved regulatory method for determination of lasalocid residues in edible animal tissues was originally developed and validated for bovine liver and, it was considered pivotal for this method to be adapted and validated in pheasant tissues as a critical prerequisite for a planned Human Food Safety (Tissue Residue) Trial for lasalocid in pheasants (Study# 2012‐235‐HFS). Full bridging of the regulatory method for lasalocid residue determination in pheasant tissues (liver and skin with adhering fat) was conducted in full compliance with Good Laboratory Practice (GLP) guidelines in order to satisfy FDA requirements. It should be noted that several previous attempts to establish and validate the regulatory method for lasalocid residue determination in pheasant tissues were unsuccessful; accordingly, it was considered crucial to establish and validate a robust and reliable analytical method based on the approved regulatory method for lasalocid determination prior to undertaking in‐life tissue depletion studies. Based upon the outcomes from this preliminary validation study, it appears that the regulatory method is reliable, sensitive and specific for lasalocid determination in pheasant tissues, though it was necessary to incorporate several minor adjustments to the regulatory method. For convenience, we included side‐by‐side comparisons of the regulatory method and the slightly modified method for both the tissue sample extraction process as well as the procedure for lasalocid determination by high‐performance liquid chromatography (HPLC) with fluorometric detection. In the latter case, it should be noted that a contemporary version of the analytical column was substituted since the column that was used for the original regulatory method is no longer available commercially. A copy of the standard operating procedure (SOP) for the modified method was submitted to the FDA-CVM Office for New Animal Drug Evaluation (ONADE) and a final decision on concurrence is expected in November of this year. The overall performance of the modified method was evaluated based on selectivity, system suitability, linearity, range, accuracy, precision, repeatability and tissue matrix interferences. Results from these evaluations revealed outcomes that were well within acceptable limits. Overall recoveries of lasalocid in spiked pheasant tissues were 83.4% (liver) and 104.4% (skin with adhering fat) with corresponding RSD values of 7.5% and 5.7%, respectively. Baseline studies of tissue controls for both liver and skin exhibited no significant peak interferences at the retention time for lasalocid. Using the aforementioned SOP for lasalocid determination, eight standard parameters were evaluated as part of the preliminary validation of this method in samples of pheasant liver and skin with adhering fat. This method will provide critical analytical support for study 2012-235-HFS, which has been in progress for more than four years.
Publications
- No publications reported this period
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Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: FARAD is a USDA-sponsored program that is a collaborative research and extension program overseen by faculty in veterinary medicine at North Carolina State University, University of California-Davis and the University of Florida. This program is an important component of the national effort to maintain a residue-free food supply for the American public. FARAD focuses on residues derived from veterinary drugs, agricultural chemicals or environmental contaminants. Since it is possible that acts of agro-terrorism could target food animals, expertise within FARAD would be key to mitigation of human exposure risks. FARAD operates to identify, extract, assemble, evaluate and distribute reviewed information about residue avoidance and mitigation to people involved in residue avoidance programs throughout the United States. The types of information available through FARAD include basic veterinary drug registration information, withdrawal times, indications for use, as well as unique technical information about the pharmacokinetics and toxicokinetics of drugs and chemicals in food animals. With implementation of cooperating international residue programs through Global FARAD (gFARAD), those data are also available for evaluation and dissemination. Under the broad umbrella of chemical food safety, FARAD fulfills several unique and specific roles, including: (1) providing an essential service to veterinarians involved in the treatment and care of major food‐producing animals. As one of the requirements for legal extra‐label drug use in a food- animal species, the Animal Drug Use Clarification Act (AMDUCA) mandates that a veterinarian must "establish a substantially extended withdrawal period prior to marketing of milk, meat, eggs, or other edible products supported by appropriate scientific information." FARAD is the only source for this required withdrawal information and provides scientifically-derived recommendations as a free service to food-service veterinarians. (2) serving as a centralized source of comprehensive pharmacokinetic information for numerous toxicants that present a significant risk exposure for food animals, including pesticides, agrochemicals, industrial chemicals and other harmful agents. During the past two years, FARAD has provided crucial advice in cases involving food animal toxicant exposures at the domestic level (e.g., cattle exposures to natural gas fracking water in Pennsylvania) as well as internationally, such as food animal exposure to radionuclides during the Japanese Fukushima reactor tragedy. Each toxicant exposure case is unique and requires thorough researching, evaluation and analysis of available data by our team of pharmacokineticists and veterinary toxicologists. (3) providing the only source for food safety information and drug withdrawal times for many minor food animal species, including sheep, goats, elk, ducks, pheasants, rabbits, salmon, cod, catfish, tilapia, lobster, shrimp and other minor-use species. These industries comprise an integral component of the nation's food supply and contribute to the overall diversification of our agricultural base. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Output measures of extension-related progress through the FARAD program are best measured by data related to the use of FARAD's Regional Access Center (calls and emails) as well as use of information resources on the FARAD web site. During the past 12 months, FARAD Regional Access Call Centers have handled approximately 1200 inquiries or an average of 3.3 calls per day. With respect to these calls, it is important to note (1) the reasons for calls are very diverse and range from the ORDINARY REQUESTS for drug withdrawal recommendations related to extra‐label drug use or accidental drug overdoses to the EXTRAORDINARY REQUESTS, which include incidents of cattle being exposed to frac water. In many cases, producers need to know how long to hold the animals before slaughter. In these cases, time is money but safety is the top concern for everyone involved. the number of animals involved with each call can be quite substantial. Recently, we started requesting information from callers in order to obtain an estimate of the numbers of animals impacted by these cases. Although these estimates are likely to be low (for example, entries for herds are frequently reported as 1 animal), we estimate that 1200 calls correspond to more than 6 million individual animals per year. Since July of 2010, on-line use of FARAD Web Resources, the FARAD home page (http://www.farad.org/) has received more than 6,800 visits or an average of more than 22 visitors per day. More than 92% of the visits are from North American locations. Regular users often bypass the FARAD home page and go directly to the VetGRAM at a rate of more than 9 per day. More than 96% of the visitors to VetGRAM were from US locations. In late 2010, a searchable database of published Withdrawal Intervals (WDI) for drugs used extra‐label was created and placed on our web site. This WDI look up tool was created with the intent to reduce the significant number of calls that involved previously published WDI recommendations. Since the launch of the WDI lookup tool, that site has been visited by 1304 individuals (average of more than 28 per day), with 99 visitors making multiple visits. More than 90% of the visitors to the WDI lookup were from locations in the U.S.
Publications
- No publications reported this period
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