@article{buur_baynes_riviere_2008, title={Estimating meat withdrawal times in pigs exposed to melamine contaminated feed using a physiologically based pharmacokinetic model}, volume={51}, ISSN={["1096-0295"]}, DOI={10.1016/j.yrtph.2008.05.003}, abstractNote={Recently melamine was found to have contaminated the feed of multiple food production species leading to concern over the ability to establish an appropriate withdrawal interval and protect the safety of the food supply. To establish an appropriate withdrawal interval, a physiologically based pharmacokinetic (PBPK) model for melamine was developed for rats and extrapolated to pigs. The rat model underpredicted plasma concentrations, but better predicted tissue residues. Correlation values for plasma, kidney, and liver were 0.59, 0.76, and 0.73, respectively. The pig model underpredicted early plasma time points but had greater accuracy at later time points which is relevant to withdrawal times. Correlation (R(2)) between predicted and observed plasma values was 0.89 with a negative intercept of -0.76. The pig model estimated a withdrawal interval (based on kidney tissue residues) of 19.2 and 20.9h for single oral exposures of 3.0 and 5.12 mg/kg of melamine, respectively. Chronic oral dosing (3.0 and 5.12 mg/kg twice daily for 7 days) yielded withdrawal intervals of 20 and 21.3h, respectively. PBPK models, such as this one, provide evidence of the usefulness in species extrapolation over a range of dosing scenarios and can be used to protect the food supply after accidental exposure in the face of little in the target species.}, number={3}, journal={REGULATORY TOXICOLOGY AND PHARMACOLOGY}, author={Buur, Jennifer L. and Baynes, Ronald E. and Riviere, Jim E.}, year={2008}, month={Aug}, pages={324–331} }
 @article{mason_baynes_buur_riviere_almond_2008, title={Sulfamethazine water medication pharmacokinetics and contamination in a commercial pig production unit}, volume={71}, ISSN={["1944-9097"]}, DOI={10.4315/0362-028X-71.3.584}, abstractNote={Sulfamethazine is often used to treat disease in the swine industry. Sulfamethazine is available as water or feed medication and historically (over the past 40 years) has been associated with residue violations in both the United States and Europe. Despite sulfamethazine's approval for use as a water medication, little research on the pharmacokinetics of the water formulation is available. Therefore, a pilot study was performed to determine the plasma levels of an approved sulfamethazine water medication. Plasma levels in pigs treated with an oral bolus (250 mg/kg), which is equivalent to the total drug consumed within a 24-h period, achieved therapeutic concentrations (50 microg/ml). Noncompartmental-based pharmacokinetic model parameters for clearance, half-life, and volume of distribution were consistent with previously published values in swine. However, the above treatment resulted in exposure of pen mates to sulfamethazine at levels currently above tolerance (0.1 ppm). Using a physiologically based pharmacokinetic model, the treatment dose simulation was compared with observed plasma levels of treated pigs. Flexibility of the physiologically based pharmacokinetic model also allowed simulation of control-pig plasma levels to estimate contamination exposure. A simulated exposure to 0.15 mg/kg twice within approximately 8 h resulted in detectable levels of sulfamethazine in the control pigs. After initial exposure, a much lower dose of 0.059 mg/kg maintained the contamination levels above tolerance for at least 3 days. These results are of concern for producers and veterinarians, because in commercial farms, the entire barn is often treated,and environmental contamination could result in residues of an unknown duration.}, number={3}, journal={JOURNAL OF FOOD PROTECTION}, author={Mason, Sharon E. and Baynes, Ronald E. and Buur, Jennifer L. and Riviere, Jim E. and Almond, Glen W.}, year={2008}, month={Mar}, pages={584–589} }
 @article{merwe_buur_riviere_2007, title={Physiologically based pharmacokinetic modeling}, DOI={10.1016/b978-012370467-2/50100-0}, journal={VETERINARY TOXICOLOGY: BASIC AND CLINICAL PRINCIPLES}, author={Merwe, Deon and Buur, Jennifer L. and Riviere, Jim E.}, year={2007}, pages={42–50} }
 @article{buur_baynes_smith_riviere_2006, title={Pharmacokinetics of flunixin meglumine in swine after intravenous dosing}, volume={29}, ISSN={["1365-2885"]}, DOI={10.1111/j.1365-2885.2006.00788.x}, abstractNote={Journal of Veterinary Pharmacology and TherapeuticsVolume 29, Issue 5 p. 437-440 Pharmacokinetics of flunixin meglumine in swine after intravenous dosing J. L. BUUR, J. L. BUUR Food Animal Residue Avoidance Databank, Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USASearch for more papers by this authorR. E. BAYNES, R. E. BAYNES Food Animal Residue Avoidance Databank, Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USASearch for more papers by this authorG. SMITH, G. SMITH Food Animal Residue Avoidance Databank, Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USASearch for more papers by this authorJ. E. RIVIERE, J. E. RIVIERE Food Animal Residue Avoidance Databank, Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USASearch for more papers by this author J. L. BUUR, J. L. BUUR Food Animal Residue Avoidance Databank, Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USASearch for more papers by this authorR. E. BAYNES, R. E. BAYNES Food Animal Residue Avoidance Databank, Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USASearch for more papers by this authorG. SMITH, G. SMITH Food Animal Residue Avoidance Databank, Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USASearch for more papers by this authorJ. E. RIVIERE, J. E. RIVIERE Food Animal Residue Avoidance Databank, Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USASearch for more papers by this author First published: 06 September 2006 https://doi.org/10.1111/j.1365-2885.2006.00788.xCitations: 36 Ronald E. Baynes, 4700 Hillsborough St, Raleigh, NC 27606, USA. E-mail: ronald_baynes@ncsu.edu Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume29, Issue5October 2006Pages 437-440 RelatedInformation}, number={5}, journal={JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS}, author={Buur, J. L. and Baynes, R. E. and Smith, G. and Riviere, J. E.}, year={2006}, month={Oct}, pages={437–440} }
 @article{buur_baynes_smith_riviere_2006, title={Use of probabilistic modeling within a physiologically based pharmacokinetic model to predict sulfamethazine residue withdrawal times in edible tissues in swine}, volume={50}, ISSN={["1098-6596"]}, DOI={10.1128/AAC.01355-05}, abstractNote={ABSTRACT
          The presence of antimicrobial agents in edible tissues of food-producing
animals remains a major public health concern. Probabilistic modeling
techniques incorporated into a physiologically based pharmacokinetic
(PBPK) model were used to predict the amounts of sulfamethazine
residues in edible tissues in swine. A PBPK model for sulfamethazine in
swine was adapted to include an oral dosing route. The distributions
for sensitive parameters were determined and were used in a Monte Carlo
analysis to predict tissue residue times. Validation of the
distributions was done by comparison of the results of a Monte Carlo
analysis to those obtained with an external data set from the
literature and an in vivo pilot study. The model was used to predict
the upper limit of the 95% confidence interval of the 99th percentile
of the population, as recommended by the U.S. Food and Drug
Administration (FDA). The external data set was used to calculate the
withdrawal time by using the tolerance limit algorithm designed by FDA.
The withdrawal times obtained by both methods were compared to the
labeled withdrawal time for the same dose. The Monte Carlo method
predicted a withdrawal time of 21 days, based on the amounts of
residues in the kidneys. The tolerance limit method applied to the
time-limited data set predicted a withdrawal time of 12 days. The
existing FDA label withdrawal time is 15 days. PBPK models can
incorporate probabilistic modeling techniques that make them useful for
prediction of tissue residue times. These models can be used to
calculate the parameters required by FDA and explore those conditions
where the established withdrawal time may not be
sufficient.}, number={7}, journal={ANTIMICROBIAL AGENTS AND CHEMOTHERAPY}, author={Buur, Jennifer and Baynes, Ronald and Smith, Geof and Riviere, Jim}, year={2006}, month={Jul}, pages={2344–2351} }
 @article{buur_baynes_craigmill_riviere_2005, title={Development of a physiologic-based pharmacokinetic model for estimating sulfamethazine concentrations in swine and application to prediction of violative residues in edible tissues}, volume={66}, ISSN={["0002-9645"]}, DOI={10.2460/ajvr.2005.66.1686}, abstractNote={AbstractObjective—To develop a flow-limited, physiologicbased pharmacokinetic model for use in estimating concentrations of sulfamethazine after IV administration to swine.Sample Population—4 published studies provided physiologic values for organ weights, blood flows, clearance, and tissue-to-blood partition coefficients, and 3 published studies provided data on plasma and other tissue compartments for model validation.Procedure—For the parent compound, the model included compartments for blood, adipose, muscle, liver, and kidney tissue with an extra compartment representing the remaining carcass. Compartments for the N-acetyl metabolite included the liver and the remaining body. The model was created and optimized by use of computer software. Sensitivity analysis was completed to evaluate the importance of each constant on the whole model. The model was validated and used to estimate a withhold interval after an IV injection at a dose of 50 mg/kg. The withhold interval was compared to the interval estimated by the Food Animal Residue Avoidance Databank (FARAD).Results—Specific tissue correlations for plasma, adipose, muscle, kidney, and liver tissue compartments were 0.93, 0.86, 0.99, 0.94, and 0.98, respectively. The model typically overpredicted concentrations at early time points but had excellent accuracy at later time points. The withhold interval estimated by use of the model was 120 hours, compared with 100 hours estimated by FARAD.Conclusions and Clinical Relevance—Use of this model enabled accurate prediction of sulfamethazine pharmacokinetics in swine and has applications for food safety and prediction of drug residues in edible tissues. (Am J Vet Res2005;66:1686–1693)}, number={10}, journal={AMERICAN JOURNAL OF VETERINARY RESEARCH}, author={Buur, JL and Baynes, RE and Craigmill, AL and Riviere, JE}, year={2005}, month={Oct}, pages={1686–1693} }
 @article{buur_baynes_yeatts_davidson_defrancesco_2005, title={Analysis of diltiazem in Lipoderm (R) transdermal gel using reversed-phase high-performance liquid chromatography applied to homogenization and stability studies}, volume={38}, ISSN={["0731-7085"]}, DOI={10.1016/j.jpba.2004.11.053}, abstractNote={A simple and novel method for the extraction and quantification of diltiazem hydrochloride was developed and applied to homogenization and stability studies. The method used solid phase extraction coupled with reversed-phase high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Validation showed inter-day recoveries ranging from 84.00 to 96.52% with relative standard deviations ranging from 12.01 to 15.94%. Intra-day recoveries ranged from 67.95 to 106.1% with relative standard deviations less than 5%. The method showed excellent linearity from 50 to 250 mg/ml in undiluted gel (R2 = 0.996). The homogenization study showed good homogenization using both 50 and 100 depression techniques. Diltiazem was stable at a concentration of 246 mg/ml for 30 days and at a concentration of 99.6 mg/ml for 60 days no matter the storage conditions explored in this study.}, number={1}, journal={JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS}, author={Buur, JL and Baynes, RE and Yeatts, JL and Davidson, G and DeFrancesco, TC}, year={2005}, month={Jun}, pages={60–65} }