@article{mason_papich_schmale_harms_davis_2019, title={Enrofloxacin Pharmacokinetics and Sampling Techniques in California Sea Hares (Aplysia californica)}, volume={58}, ISSN={1559-6109}, url={http://dx.doi.org/10.30802/AALAS-JAALAS-18-000072}, DOI={10.30802/AALAS-JAALAS-18-000072}, abstractNote={This pharmacokinetic study was designed to determine the pharmacokinetics of enrofloxacin at 5 mg/kg when given to sea hares in their hemolymph. Enrofloxacin is a commonly used antimicrobial in veterinary medicine and potentially could be used to treat sea hares exposed to susceptible
 bacterial species. We individually identified 8 juvenile Aplysia californica and group housed them in an open seawater flow system at 14 to 18 °C; 2 served as untreated controls. The remaining 6 animals were injected into the hemocoel with 0.030 mL of 22.7 mg/mL enrofloxacin (average
 dose, 5 to 6 mg/kg). At each time point, 300 μL hemolymph was collected from the pedal hemolymph sinus and HPLC-analyzed for enrofloxacin and ciprofloxacin levels. Enrofloxacin was detected in all dosed animals, at an average peak concentration of 3 μg/mL in hemolymph, and remained in
 the body for 20.3 h with an average clearance of 0.19 μg × h/mL. No ciprofloxacin was detected in any Aplysia in this study. Hemocoel injection appears to be an effective way to administer enrofloxacin to Aplysia and reach clinically relevant concentrations. Enrofloxacin reached therapeutic target concentrations in A. californica when dosed according to the regimen described in the current report.}, number={2}, journal={Journal of the American Association for Laboratory Animal Science}, publisher={American Association for Laboratory Animal Science}, author={Mason, Sharon E and Papich, Mark G and Schmale, Michael C and Harms, Craig A and Davis, Sally A}, year={2019}, month={Mar}, pages={231–234} }
 @article{mason_mullen_washburn_anderson_baynes_2018, title={Comparison of the pharmacokinetics of plant-based treatments in milk and plasma of USDA organic dairy cattle with and without mastitis}, volume={35}, ISSN={["1944-0057"]}, DOI={10.1080/19440049.2018.1502475}, abstractNote={ABSTRACT Organic dairy products are the second largest sector of the organic food market. Organic dairy products come from United States Department of Agriculture (USDA) certified organic dairy cattle that meet USDA organic standards. Organic dairy cattle in the US cannot be treated with antibiotics for mastitis, one of the costliest diseases of dairy cattle, and thus effective alternatives are needed. When any compound (medication or other non-food product) is used in a food producing animal, a withhold time for that compound that meets US Food and Drug Administration (FDA) standards for food safety must be applied to the animal and its products (like milk). However, there are no US FDA products approved for mastitis that maintain USDA certified organic dairy cattle’s organic status. Thus, we studied the pharmacokinetics of 3 compounds (garlic, thymol and carvacrol) used on organic both healthy and mastitic organic dairy cattle. We also used this information to estimate a milk withhold time using methods consistent with US FDA requirements. For thymol intra-mammary and carvacrol intra-mammary or topical administration, all compounds were partially absorbed into the body from the milk or skin. Thymol and carvacrol are measurable in plasma (at 0.0183 and 0.0202 µg/mL, respectively) after intramammary administration with similar elimination half lives of 1.7 h. Milk concentrations of thymol and carvacrol are much higher at 2.958 and 4.487 µg/mL in healthy cattle, respectively. Concentrations are not significantly different in cows with mastitis as compared to those in healthy cows. Despite these compounds being natural products, they should have a withhold time for milk of at least 24 h after administration. For garlic, levels remained below the limit of detection in milk and plasma and thus no withdrawal time appears to be needed for milk.}, number={9}, journal={FOOD ADDITIVES AND CONTAMINANTS PART A-CHEMISTRY ANALYSIS CONTROL EXPOSURE & RISK ASSESSMENT}, author={Mason, Sharon E. and Mullen, Keena A. E. and Washburn, Steven P. and Anderson, Kevin L. and Baynes, Ronald E.}, year={2018}, pages={1716–1727} }
 @article{mason_mullen_anderson_washburn_yeatts_baynes_2017, title={Pharmacokinetic analysis of thymol, carvacrol and diallyl disulfide after intramammary and topical applications in healthy organic dairy cattle}, volume={34}, ISSN={1944-0049 1944-0057}, url={http://dx.doi.org/10.1080/19440049.2017.1285056}, DOI={10.1080/19440049.2017.1285056}, abstractNote={ABSTRACT Mastitis is among the most costly concerns for dairy producers whether cattle are managed conventionally or organically. Unfortunately, there are no USFDA-approved mastitis treatments that allow dairy cows in the United States to maintain organic dairy status. We investigated the plasma pharmacokinetics of three organic mastitis products currently used by organic producers and organic dairy veterinarians. Those products include intramammary, topical and intravaginal preparations, each dosed at two levels. Additionally, tissue data were collected for kidney, liver and fat in order to estimate a withholding time for each of the products. The lower limit of quantification (LOQ) and lower limit of detection (LOD) were 0.001 and 0.0005 µg ml–1, respectively, in plasma and all tissues except fat for both thymol and carvacrol. Fat had an LOQ of 0.01 µg ml–1 and an LOD of 0.005 µg ml–1 for thymol and carvacrol. Diallyl disulfide had an LOQ of 0.005 µg ml–1 and LOD of 0.001 µg ml–1 in all tissues. For diallyl disulfide (garlic), no levels above 0.001 µg ml–1 were measurable in plasma or tissues. For topical and intramammary products, levels were measurable in the plasma, liver, kidney and fat up to 72 h after the last dose. The plasma half-lives were short for thymol (approximately 1.6 h) and carvacrol (approximately 1.5 h), whereas the estimated half-lives for these substances in tissues ranged from 13.9 to 31.5 h for thymol and from 16.9 to 25 h for carvacrol. The predicted amount of time that the molecules would be found in the body based on the slowest depletion time of liver tissue was 13 days for thymol and 10 days for carvacrol. The apparent half-life of topically applied carvacrol was approximately 4.5 h in plasma, with an estimated withhold time of 10 days. These times were calculated using the USFDA’s tolerance limit method for meat withdrawal times.}, number={5}, journal={Food Additives & Contaminants: Part A}, publisher={Informa UK Limited}, author={Mason, Sharon E. and Mullen, Keena A. E. and Anderson, Kevin L. and Washburn, Steven P. and Yeatts, James L. and Baynes, Ronald E.}, year={2017}, month={Feb}, pages={1–10} }
 @article{mason_almond_riviere_baynes_2012, title={Evaluation of factors important in modeling plasma concentrations of tetracycline hydrochloride administered in water in swine}, volume={73}, ISSN={["1943-5681"]}, DOI={10.2460/ajvr.73.10.1641}, abstractNote={Abstract
Objective—To model the plasma tetracycline concentrations in swine (Sus scrofa domestica) treated with medication administered in water and determine the factors that contribute to the most accurate predictions of measured plasma drug concentrations.
Sample—Plasma tetracycline concentrations measured in blood samples from 3 populations of swine.
Procedures—Data from previous studies provided plasma tetracycline concentrations that were measured in blood samples collected from 1 swine population at 0, 4, 8, 12, 24, 32, 48, 56, 72, 80, 96, and 104 hours and from 2 swine populations at 0, 12, 24, 48, and 72 hours hours during administration of tetracycline hydrochloride dissolved in water. A 1-compartment pharmacostatistical model was used to analyze 5 potential covariate schemes and determine factors most important in predicting the plasma concentrations of tetracycline in swine.
Results—2 models most accurately predicted the tetracycline plasma concentrations in the 3 populations of swine. Factors of importance were body weight or age of pig, ambient temperature, concentration of tetracycline in water, and water use per unit of time.
Conclusions and Clinical Relevance—The factors found to be of importance, combined with knowledge of the individual pharmacokinetic and chemical properties of medications currently approved for administration in water, may be useful in more prudent administration of approved medications administered to swine. Factors found to be important in pharmacostatistical models may allow prediction of plasma concentrations of tetracycline or other commonly used medications administered in water. The ability to predict in vivo concentrations of medication in a population of food animals can be combined with bacterial minimum inhibitory concentrations to decrease the risk of developing antimicrobial resistance.}, number={10}, journal={AMERICAN JOURNAL OF VETERINARY RESEARCH}, author={Mason, Sharon E. and Almond, Glen W. and Riviere, Jim E. and Baynes, Ronald E.}, year={2012}, month={Oct}, pages={1641–1649} }
 @article{mcphee_anderson_yeatts_mason_barlow_baynes_2011, title={Hot topic: Milk and plasma disposition of thymol following intramammary administration of a phytoceutical mastitis treatment}, volume={94}, ISSN={["1525-3198"]}, DOI={10.3168/jds.2010-3988}, abstractNote={Despite the recent growth of the organic dairy industry, organic producers and veterinarians have limited information when choosing mastitis treatments for animals in organic dairy production. Organic producers commonly administer homeopathic or other plant-based products without having research evaluating the efficacy of these products and using estimated or no withholding times to treat mastitis and other health problems in their herds. In this pilot study, we attempted to identify several active ingredients of Phyto-Mast (Penn Dutch Cow Care, Narvon, PA), a plant-based mastitis treatment used on organic dairy farms, and to quantify the product residue in milk and plasma after intramammary administration. We developed an assay to quantify thymol (one of the active ingredients in Phyto-Mast) in milk and plasma using gas chromatography and mass spectrometry (GC-MS). Thymol is a volatile aromatic compound with antiinflammatory properties. As a model for dairy cows, 5 healthy, lactating alpine dairy goats were given 5 mL of Phyto-Mast per udder half. For 10 d following treatment, we analyzed blood and milk samples for thymol residues using GC-MS. The GC-MS assay was very sensitive for thymol detection, to a concentration of 0.01 μg/mL in plasma. Using thymol as a marker, Phyto-Mast was detectable and quantifiable in plasma beginning with the 15-min posttreatment sample, but was no longer detectable in the 4-h posttreatment sample. Thymol residues were only detected in the 12-h posttreatment milk sample. An inflammatory response was not evident in the udder following phytoceutical administration. Although this study provides information about the elimination of thymol, the product contains several other active chemicals, which may have different pharmacokinetic behaviors. Further analysis and additional study animals will help to determine a milk withholding time for Phyto-Mast. Given the recent growth of the organic dairy industry, understanding the pharmacokinetics of therapeutics used in organic production and developing accurate withholding recommendations will help to ensure milk safety.}, number={4}, journal={JOURNAL OF DAIRY SCIENCE}, author={McPhee, C. S. and Anderson, K. L. and Yeatts, J. L. and Mason, S. E. and Barlow, B. M. and Baynes, R. E.}, year={2011}, month={Apr}, pages={1738–1743} }
 @article{baynes_barlow_mason_riviere_2010, title={Disposition of melamine residues in blood and milk from dairy goats exposed to an oral bolus of melamine}, volume={48}, ISSN={["0278-6915"]}, DOI={10.1016/j.fct.2010.04.040}, abstractNote={There have been numerous reports of melamine-related illnesses following oral exposure to this contaminant. These studies have been in monogastrics, but there are few reports of adverse effects and pharmacokinetics of melamine in ruminants. The purpose of this project was to determine how melamine is systemically cleared from the blood and milk in lactating animals. Five lactating goats were given a single oral dose of 40 mg/kg body weight. Milk and blood samples were collected for 144 h and analyzed to determine key pharmacokinetic parameters. The apparent plasma half-life (11.12 h) was 3 times longer in these ruminants than that reported in monogastrics and the apparent volume of distribution was more than 6 times greater than that reported in monogastrics. The milk had an apparent half-life of 9.44 h and less than 0.4% of the melamine dose was eliminated in milk. All milk samples were below the LOQ at 4 days (96 h) after exposure. In summary, the pharmacokinetics of melamine in ruminants is not predictive from monogastrics and milk from similarly exposed animals should be condemned for at least 4 days after the last exposure to avoid violation of proposed MRLs or safe levels for milk.}, number={8-9}, journal={FOOD AND CHEMICAL TOXICOLOGY}, author={Baynes, Ronald E. and Barlow, Beth and Mason, Sharon E. and Riviere, Jim E.}, year={2010}, pages={2542–2546} }
 @article{young_smith_leavens_wetzlich_baynes_mason_riviere_tell_2011, title={Pharmacokinetics of tulathromycin following subcutaneous administration in meat goats}, volume={90}, ISSN={["0034-5288"]}, DOI={10.1016/j.rvsc.2010.06.025}, abstractNote={Tulathromycin is a triamilide antibiotic that maintains therapeutic concentrations for an extended period of time. The drug is approved for the treatment of respiratory disease in cattle and swine and is occasionally used in goats. To investigate the pharmacokinetics of tulathromycin in meat goats, 10 healthy Boer goats were administered a single 2.5 mg/kg subcutaneous dose of tulathromycin. Plasma concentrations were measured by ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC–MS/MS) detection. Plasma maximal drug concentration (Cmax) was 633 ± 300 ng/ml (0.40 ± 0.26 h post-subcutaneous injection). The half-life of tulathromycin in goats was 110 ± 19.9 h. Tulathromycin was rapidly absorbed and distributed widely after subcutaneous injection 33 ± 6 L/kg. The mean AUC of the group was 12,500 ± 2020 h ng/mL for plasma. In this study, it was determined that the pharmacokinetics of tulathromycin after a single 2.5 mg/kg SC injection in goats were very similar to what has been previously reported in cattle.}, number={3}, journal={RESEARCH IN VETERINARY SCIENCE}, author={Young, Gabrielle and Smith, Geof W. and Leavens, Teresa L. and Wetzlich, Scott E. and Baynes, Ronald E. and Mason, Sharon E. and Riviere, Jim E. and Tell, Lisa A.}, year={2011}, month={Jun}, pages={477–479} }
 @article{lee_leavens_mason_monteiro-riviere_riviere_2009, title={Comparison of Quantum Dot Biodistribution with a Blood-Flow-Limited Physiologically Based Pharmacokinetic Model}, volume={9}, ISSN={1530-6984 1530-6992}, url={http://dx.doi.org/10.1021/nl803481q}, DOI={10.1021/nl803481q}, abstractNote={A physiologically based pharmacokinetic model with partition coefficients estimated from quantum dot (QD) 705 biodistribution was compared with the biodistribution of other QDs in mice and rats to determine the model's predictive ability across QD types, species, and exposure routes. The model predicted the experimentally observed persistence of QDs in tissues but not early time profiles or different QD biodistribution. Therefore, more complex models will be needed to better predict QD biodistribution in vivo.}, number={2}, journal={Nano Letters}, publisher={American Chemical Society (ACS)}, author={Lee, Hyun A. and Leavens, Teresa L. and Mason, Sharon E. and Monteiro-Riviere, Nancy A. and Riviere, Jim E.}, year={2009}, month={Jan}, pages={794–799} }
 @article{mason_baynes_almond_riviere_scheidt_2009, title={Pharmacology of tetracycline water medication in swine}, volume={87}, ISSN={["1525-3163"]}, DOI={10.2527/jas.2009-1877}, abstractNote={Medicating drinking water with tetracycline is commonly used in swine production systems to treat and prevent disease outbreaks. However, little information is known of the pharmacokinetics of this medication in water formulations. Twenty-four barrows, divided into 1 control group (of nontreated animals) and 3 equally sized treatments groups (n = 6/group), were treated with tetracycline water medication for 5 d at 125, 250, and 500 mg/L. Blood samples were collected at 0 (prestudy), 4, 8, 12, 24, 32, 48, 56, 72, 80, 96, and 104 h after exposure. Data analyses consisted of a noncompartmental pharmacokinetic analysis and statistical analysis of steady state concentrations with repeated measures ANOVA and multiple-comparison testing to determine whether plasma concentrations differed among groups. Derived pharmacokinetic parameters were consistent with previously published feed and intravenous data. Plasma tetracycline concentrations at steady state were 0, 0.33, 0.47, and 0.77 microg/mL for 0-, 125-, 250-, and 500-mg/L exposures, respectively. Treatment group steady-state plasma concentrations were significantly different from plasma concentrations in control animals (P < 0.0001); however, whereas the 125- and 250-mg/L groups were significantly different from the 500-mg/L group (P < 0.0001), their mean plasma tetracycline concentrations did not differ from one another. Furthermore, the study showed that tetracycline oral bioavailability is very small. The dose response curve also shows that concentrations of plasma tetracycline increase linearly, yet not in a 1 to 1 ratio, to the direct increase in water medication dose.}, number={10}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Mason, S. E. and Baynes, R. E. and Almond, G. W. and Riviere, J. E. and Scheidt, A. B.}, year={2009}, month={Oct}, pages={3179–3186} }
 @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{baynes_smith_mason_barrett_barlow_riviere_2008, title={Pharmacokinetics of melamine in pigs following intravenous administration}, volume={46}, DOI={10.1016/j.fct.2007.11.013}, abstractNote={Melamine-contaminated pet food was recently added as a supplement to livestock feed. There is little or no information concerning the pharmacokinetics of melamine in livestock, and the aim of this study was to obtain pharmacokinetic parameters for this contaminant in pigs. Melamine was administered intravenously to five weanling pigs at a dose of 6.13 mg/kg and plasma samples were collected over 24 h, extracted for melamine, and then analyzed by HPLC–UV. The data was shown to best fit a one-compartment model with melamine’s half-life of 4.04 (±0.37) h, clearance of 0.11 (±0.01) L/h/kg, and volume of distribution of 0.61 (±0.04) L/kg. These data are comparable to the only mammalian study in rats and suggests that melamine is readily cleared by the kidney and there is unlikely to be significant tissue binding. Further tissue residue studies are required to assess the depletion kinetics of this contaminant in the pig which will determine whether residue levels in the kidney should be of public health concern if pigs were exposed to a similar dose.}, number={3}, journal={Food and Chemical Toxicology}, author={Baynes, R. E. and Smith, Geof and Mason, S. E. and Barrett, E. and Barlow, B. M. and Riviere, J. E.}, year={2008}, pages={1196–1200} }
 @article{mason_suyemoto_baynes_almond, title={Stability and bioactivity of tetracycline hydrochloride water medication in a swine production unit}, volume={19}, number={2}, journal={Journal of Swine Health and Production}, author={Mason, S. E. and Suyemoto, M. and Baynes, R. and Almond, G.}, pages={107–111} }