Portfolio of Our Published Work

We provided bioanalytical services including: development and validation of novel analytical methods, analysis of specimens and central lab funtions in support of the following:



Sex-specific Multi-level 3D Genome Dynamics in the Mouse Brain

Quantification of serum oestradiol levels using high-performance Liquid Chromatography with Tandem Mass Spectometry (HPLC/MS–MS) was performed.

Rocks D, Shukla M, Ouldibbat L, Finnemann SC, Kalluchi A, Rowley MJ, Kundakovic M. Nat Commun. 2022 Jun 15;13(1):3438. doi: 10.1038/s41467-022-30961-w. PMID: 35705546; PMCID: PMC9200740.


External Evaluation of Two Pediatric Population Pharmacokinetics Models of Oral Trimethoprim and Sulfamethoxazole

The plasma samples of both studies were quantified using validated high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS-MS) assays.   The LLOQs were 0.025 mg/liter for TMP and 0.25 mg/liter for SMX.

Wu YSS, Cohen-Wolkowiez M, Hornik CP, Gerhart JG, Autmizguine J, Cobbaert M, Gonzalez D; Best Pharmaceuticals for Children Act—Pediatric Trials Network Steering Committee. Antimicrob Agents Chemother. 2021 Jun 17;65(7):e0214920. doi: 10.1128/AAC.02149-20. Epub 2021 Jun 17. PMID: 33903114; PMCID: PMC8407045.


Optimal Dosing of Meropenem in a Small Cohort of Critically Ill Children Receiving Continuous Renal Replacement Therapy

Meropenem concentrations in plasma and the effluent were quantified using a validated high-performance liquid chromatography-tandem mass spectrometry bioanalytical assay.

Tan WW, Watt KM, Boakye-Agyeman F, Cohen-Wolkowiez M, Mok YH, Yung CF, Chan YH. J Clin Pharmacol. 2021 Jun;61(6):744-754. doi: 10.1002/jcph.1798. Epub 2021 Jan 12. PMID: 33314163; PMCID: PMC8089047.


The Tox21 10K Compound Library: Collaborative Chemistry Advancing Toxicology

Analytical QC analysis of Tox21 plates were performed over the course of several years and included liquid chromatography mass spectroscopy (LCMS), gas chromatography mass spectroscopy (GCMS), and nuclear magnetic resonance (NMR) spectroscopy on all or portions of the library.

Richard AM, Huang R, Waidyanatha S, Shinn P, Collins BJ, Thillainadarajah I, Grulke CM, Williams AJ, Lougee RR, Judson RS, Houck KA, Shobair M, Yang C, Rathman JF, Yasgar A, Fitzpatrick SC, Simeonov A, Thomas RS, Crofton KM, Paules RS, Bucher JR, Austin CP, Kavlock RJ, Tice RR. Chem Res Toxicol. 2021 Feb 15;34(2):189-216. doi: 10.1021/acs.chemrestox.0c00264. Epub 2020 Nov 3. PMID: 33140634; PMCID: PMC7887805.


Pharmacokinetics of Hydrochlorothiazide in Children: A Potential Surrogate for Renal Secretion Maturation

Performed Pediatric Trials Network central laboratory functions.

Commander SJ, Wu H, Boakye-Agyeman F, Melloni C, Hornik CD, Zimmerman K, Al-Uzri A, Mendley SR, Harper B, Cohen-Wolkowiez M, Hornik CP; Best Pharmaceuticals for Children Act-Pediatric Trials Network Steering Committee. J Clin Pharmacol. 2021 Mar;61(3):368-377. doi: 10.1002/jcph.1739. Epub 2020 Oct 7. PMID: 33029806; PMCID: PMC8232568.


Physiologically-Based Pharmacokinetic Modeling Characterizes the CYP3A-Mediated Drug-Drug Interaction Between Fluconazole and Sildenafil in Infants

Fluconazole and Sildenafil method development, validation and bioanalysis.

Salerno SN, Edginton A, Gerhart JG, Laughon MM, Ambalavanan N, Sokol GM, Hornik CD, Stewart D, Mills M, Martz K, Gonzalez D; Pharmaceuticals for Children Act - Pediatric Trials Network Steering Committee. Clin Pharmacol Ther. 2021 Jan;109(1):253-262. doi: 10.1002/cpt.1990. Epub 2020 Aug 22. PMID: 32691891; PMCID: PMC8138939.


Population Pharmacokinetics of Metoclopramide in Infants, Children, and Adolescents

Plasma samples were stored and analyzed.   Extracts were analyzed by high‐performance liquid chromatography‐tandem mass spectrometry (HPLC‐MS/MS) using positive ion multiple reaction monitoring.   The HPLC‐MS/MS method was validated over the range 1–1,000 ng/mL and the lower limit of quantification was 1 ng/mL using a 10 μL aliquot of plasma.

Ge S, Mendley SR, Gerhart JG, Melloni C, Hornik CP, Sullivan JE, Atz A, Delmore P, Tremoulet A, Harper B, Payne E, Lin S, Erinjeri J, Cohen-Wolkowiez M, Gonzalez D; Best Pharmaceuticals for Children Act - Pediatric Trials Network Steering Committee. Clin Transl Sci. 2020 Nov;13(6):1189-1198. doi: 10.1111/cts.12803. Epub 2020 May 27. PMID: 32324313; PMCID: PMC7719387.


In Utero and Lactational Exposure to Flame Retardants Disrupts Rat Ovarian Follicular Development and Advances Puberty

Comprehensive steroid panel analysis (cortisol, corticosterone, 11-deoxycortisol, androstenedione, deoxycorticosterone, testosterone, OH-progesterone, progesterone, pregnenolone, estrone, and estradiol) using HPLC/MS/MS was performed.

Allais A, Albert O, Lefèvre PLC, Wade MG, Hales BF, Robaire B. Toxicol Sci. 2020 Jun 1;175(2):197-209. doi: 10.1093/toxsci/kfaa044. PMID: 32207525; PMCID: PMC7253202.


Oxidative Stress Biomarker Decreased in Preterm Neonates Treated With Kangaroo Mother Care

Allantoin measurements in urine samples, performed using liquid chromatography with tandem mass spectrometry (LC/MS/MS).

Forde D, Deming DD, Tan JC, Phillips RM, Fry-Bowers EK, Barger MK, Bahjri K, Angeles DM, Boskovic DS. Biol Res Nurs. 2020 Apr;22(2):188-196. doi: 10.1177/1099800419900231. Epub 2020 Jan 24. PMID: 31973579; PMCID: PMC7273802.


Population pharmacokinetics of sildenafil in extremely premature infants

Sildenafil and DMS concentrations in plasma were quantified using a validated high‐performance liquid chromatography–tandem mass spectrometry assay.   The lower limits of quantification for sildenafil and DMS were 0.1 and 0.2 ng/mL, respectively.

Gonzalez D, Laughon MM, Smith PB, Ge S, Ambalavanan N, Atz A, Sokol GM, Hornik CD, Stewart D, Mundakel G, Poindexter BB, Gaedigk R, Mills M, Cohen-Wolkowiez M, Martz K, Hornik CP; Best Pharmaceuticals for Children Act - Pediatric Trials Network Steering Committee. Br J Clin Pharmacol. 2019 Dec;85(12):2824-2837. doi: 10.1111/bcp.14111. Epub 2019 Dec 15. PMID: 31475367; PMCID: PMC6955411.


Dosing of Continuous Fentanyl Infusions in Obese Children: A Population Pharmacokinetics Analysis

Developed, validated and analyzed plasma for fentanyl concentrations by liquid chromatography-tandem mass spectrometry (LC/MS-MS)   The limit of quantification of the assay was 0.02 ng/mL.

Maharaj AR, Wu H, Zimmerman KO, Speicher DG, Sullivan JE, Watt K, Al-Uzri A, Payne EH, Erinjeri J, Lin S, Harper B, Melloni C, Hornik CP; Best Pharmaceuticals for Children Act - Pediatric Trials Network Steering Committee. J Clin Pharmacol. 2019 Dec 8:10.1002/jcph.1562. doi: 10.1002/jcph.1562. Epub ahead of print. PMID: 31814149; PMCID: PMC7591270.


Development of a Prospective Real-World Data Clinical Registry of Children and Adolescents With Migraine

Central labortory responsibilities.

Hornik CP, Gelfand AA, Szperka CL, Pezzuto T, Utevsky A, Kessel S, McCune S, Alexander JJ, Benjamin DK Jr, Cohen-Wolkowiez M. Headache. 2020 Feb;60(2):405-415. doi: 10.1111/head.13714. Epub 2019 Nov 22. PMID: 31758549; PMCID: PMC7194169.


Population Pharmacokinetics of Doxycycline in Children

Doxycycline concentrations in plasma were quantified using a validated high performance liquid chromatography (HPLC)–tandem mass spectrometry (MS-MS) assay.   The lower limit of quantification for doxycycline was 50 ng/mL.

Thompson EJ, Wu H, Melloni C, et al. Antimicrob Agents Chemother. 2019;63(12):e01508-19. doi:10.1128/AAC.01508-19


Development of a Prioritization Method for Chemical-mediated Effects on Steroidogenesis using an Integrated Statistical Analysis of High-throughput H295R Data

Frozen medium was thawed, and hormone concentrations were quantified using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS).   Thirteen hormone measurements were made (pregnenolone, 17α-hydroxypregnenolone, progesterone, 17α-hydroxyprogesterone, deoxycorticosterone, corticosterone, 11-deoxycotrisol, cortisol, dehydroepiandrosterone, androstenedione, testosterone, estrone, 17β-estradiol).

Haggard DE, Setzer RW, Judson RS, Paul Friedman K. Regul Toxicol Pharmacol. 2019 Dec;109:104510. doi: 10.1016/j.yrtph.2019.104510. Epub 2019 Oct 29. PMID: 31676319; PMCID: PMC8667012.


Population Pharmacokinetics and Safety of Piperacillin-Tazobactam Extended Infusions in Infants and Children

Piperacillin and tazobactam concentrations were quantified using validated liquid chromatography-tandem mass spectrometry assays.   The lower limit of quantification (LLOQ) was 0.1 mg/L for both piperacillin and tazobactam.

Thibault C, Lavigne J, Litalien C, Kassir N, Théorêt Y, Autmizguine J. Antimicrob Agents Chemother. 2019;63(11):e01260-19. Published 2019 Oct 22. doi:10.1128/AAC.01260-19


Rifampin Pharmacokinetics and Safety in Preterm and Term Infants

Rifampin concentrations were quantified using a validated liquid chromatography-tandem spectrometry assay.   The validation range for the assay was 0.05 to 50 μg/mL.

Smith PB, Cotten CM, Hudak ML, et al. Antimicrob Agents Chemother. 2019;63(6):e00284-19. Published 2019 May 24. doi:10.1128/AAC.00284-19


Physiologically Based Pharmacokinetic Modeling of Fluconazole Using Plasma and Cerebrospinal Fluid Samples From Preterm and Term Infants

The prophylaxis study samples were analyzed via a high‐performance liquid chromatography/tandem mass spectrometry method developed.   Performed central laboratory funtions.

Gerhart JG, Watt KM, Edginton A, Wade KC, Salerno SN, Benjamin DK Jr, Smith PB, Hornik CP, Cohen-Wolkowiez M, Duara S, Ross A, Shattuck K, Stewart DL, Neu N, Gonzalez D; Best Pharmaceuticals for Children Act-Pediatric Trials Network Steering Committee. CPT Pharmacometrics Syst Pharmacol. 2019 Jul;8(7):500-510. doi: 10.1002/psp4.12414. Epub 2019 May 22. PMID: 31087536; PMCID: PMC6656941.


Pharmacokinetics of Ticarcillin–clavulanate in Premature Infants

Total ticarcillin concentrations in plasma were quantified using a validated HPLC/MS/MS assay.   The lower limit of quantification was 500 ng/mL.

Watt KM, Hornik CP, Balevic SJ, et al. Br J Clin Pharmacol. 2019;85(5):1021-1027. doi:10.1111/bcp.13882


The Fungal Cyp51-Specific Inhibitor VT-1598 Demonstrates In Vitro and In Vivo Activity against Candida auris

VT-1598 concentrations were determined by liquid chromatography-tandem mass spectrometry (LC/MS-MS).

Wiederhold NP, Lockhart SR, Najvar LK, et al. Antimicrob Agents Chemother. 2019;63(3):e02233-18. Published 2019 Feb 26. doi:10.1128/AAC.02233-18


A Population-Based Pharmacokinetic Model Approach to Pantoprazole Dosing for Obese Children and Adolescents

Pantoprazole and pantoprazole-sulfone concentrations in plasma were quantified using a validated high-performance liquid chromatography tandem mass spectrometry (HPLC/MS-MS) assay.   The lower limit of quantification for both pantoprazole and pantoprazole-sulfone were 10 ng/mL.

Shakhnovich V, Brian Smith P, Guptill JT, et al. Paediatr Drugs. 2018;20(5):483-495. doi:10.1007/s40272-018-0305-1


Population Pharmacokinetics and Exploratory Exposure-Response Relationships of Diazepam in Children Treated for Status Epilepticus

Diazepam concentrations were quantified using a validated liquid chromatography-tandem spectrometry assay.   The lower limit of quantification was 1 ng/mL.

Ku LC, Hornik CP, Beechinor RJ, et al. CPT Pharmacometrics Syst Pharmacol. 2018;7(11):718-727. doi:10.1002/psp4.12349


VT-1598 inhibits the in vitro growth of mucosal Candida strains and protects against fluconazole-susceptible and -resistant oral candidiasis in IL-17 signalling-deficient mice

VT-1598 levels were determined in tongue homogenates and plasma using LC-MS/MS.

Break TJ, Desai JV, Healey KR, et al. J Antimicrob Chemother. 2018;73(8):2089-2094. doi:10.1093/jac/dky170


The Novel Fungal Cyp51 Inhibitor VT-1598 Is Efficacious in Experimental Models of Central Nervous System Coccidioidomycosis Caused by Coccidioides posadasii and Coccidioides immitis

Plasma concentrations of VT-1598 and the positive control VT-1161 were determined by liquid chromatography/tandem mass spectrometry.

Wiederhold NP, Shubitz LF, Najvar LK, et al. Antimicrob Agents Chemother. 2018;62(4):e02258-17. Published 2018 Mar 27. doi:10.1128/AAC.02258-17


A Pharmacokinetic Model for Amiodarone in Infants Developed from an Opportunistic Sampling Trial and Published Literature Data

Amiodarone plasma concentrations were quantified using a validated high-performance liquid chromatography tandem-mass spectrometry assay.   The calibration range was between 5–5000 ng/mL using a 10 uL sample volume.

Dallefeld SH, Atz AM, Yogev R, et al. J Pharmacokinet Pharmacodyn. 2018;45(3):419-430. doi:10.1007/s10928-018-9576-y


Obese Children Require Lower Doses of Pantoprazole Than Nonobese Peers to Achieve Equal Systemic Drug Exposures

Pantoprazole and pantoprazole-sulfone concentrations in plasma were quantified using a validated high-performance liquid chromatography tandem mass spectrometry assay.   The lower limit of quantification for both pantoprazole and pantoprazole sulfone were 10 ng/mL.

Shakhnovich V, Smith PB, Guptill JT, et al. J Pediatr. 2018;193:102-108.e1. doi:10.1016/j.jpeds.2017.10.011


Comparative Analysis of Ampicillin Plasma and Dried Blood Spot Pharmacokinetics in Neonates

Ampicillin concentrations were measured using a validated bioanalytical high-pressure liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay.   The validated range of the method for ampicillin based on 10 μLs of human plasma was 0.05 to 50 μg/mL.

Le J, Poindexter B, Sullivan JE, et al. Ther Drug Monit. 2018;40(1):103-108. doi:10.1097/FTD.0000000000000466


Population Pharmacokinetics of Trimethoprim-Sulfamethoxazole in Infants and Children

Trimethoprim (TMP) and Sulfamethoxazole (SMX) concentrations were quantified using validated liquid chromatography-tandem mass spectrometry assays.   The TMP validation range was 25 to 50,000 ng/mL.   The SMX validation range was 250 to 500,000 ng/mL.

Autmizguine J, Melloni C, Hornik CP, et al. Antimicrob Agents Chemother. 2017;62(1):e01813-17. Published 2017 Dec 21. doi:10.1128/AAC.01813-17


Development of a Pediatric Physiologically Based Pharmacokinetic Model of Clindamycin Using Opportunistic Pharmacokinetic Data

Clindamycin plasma concentrations were quantified using a validated liquid chromatography-tandem spectrometry (LC-MS/MS) assay.   The validation range for the assay was 50–50,000 ng/mL.

Hornik CP, Wu H, Edginton AN, Watt K, Cohen-Wolkowiez M, Gonzalez D. Clin Pharmacokinet. 2017;56(11):1343-1353. doi:10.1007/s40262-017-0525-5


VT-1161 protects mice against oropharyngeal candidiasis caused by fluconazole-susceptible and -resistant Candida albicans

VT-1161 and VT-1129 concentrations were determined using LC–MS/MS with electrospray ionization.

Break TJ, Desai JV, Natarajan M, et al. J Antimicrob Chemother. 2018;73(1):151-155. doi:10.1093/jac/dkx352


Antifungal Extraction by the Extracorporeal Membrane Oxygenation Circuit

Fluconazole concentrations were measured using HPLC/MS-MS.   The lower limit of quantification (LLOQ) was .01 mg/L with a calibration curve range of .01–10 mg/L.

Watt KM, Cohen-Wolkowiez M, Williams DC, et al. J Extra Corpor Technol. 2017;49(3):150-159.


Prophylactic Treatment with VT-1161 Protects Immunosuppressed Mice from Rhizopus arrhizus var. arrhizus Infection

VT-1161 levels were measured by liquid chromatography-tandem mass spectrometry (LC/MS-MS).

Gebremariam T, Alkhazraji S, Lin L, et al. Antimicrob Agents Chemother. 2017;61(9):e00390-17. Published 2017 Aug 24. doi:10.1128/AAC.00390-17


Population Pharmacokinetics and Exploratory Pharmacodynamics of Lorazepam in Pediatric Status Epilepticus

Plasma lorazepam concentrations were quantified using a validated liquid chromatography-tandem mass spectrometry assay developed by the Pediatric Trials Network (PTN) central laboratory (OpAns, Durham, NC).   Calibration standards ranged from 1 to 500 ng/mL in human plasma.

Gonzalez D, Chamberlain JM, Guptill JT, et al. Clin Pharmacokinet. 2017;56(8):941-951. doi:10.1007/s40262-016-0486-0


Efficacy of the Investigational Antifungal VT-1161 in Treating Naturally Occurring Coccidioidomycosis in Dogs

VT-1161 was extracted from plasma samples and analyzed using high-performance liquid chromatography with tandem mass spectrometry using electrospray ionization.

Shubitz LF, Roy ME, Trinh HT, Hoekstra WJ, Schotzinger RJ, Garvey EP. Antimicrob Agents Chemother. 2017;61(5):e00111-17. Published 2017 Apr 24. doi:10.1128/AAC.00111-17


Pharmacokinetics of Clindamycin in Obese and Nonobese Children

Clindamycin concentrations collected from the three trials were quantified using a validated liquid chromatography-tandem spectrometry assay.   The lower limit of quantification was 50 ng/mL.

Smith MJ, Gonzalez D, Goldman JL, et al. Antimicrob Agents Chemother. 2017;61(4):e02014-16. Published 2017 Mar 24. doi:10.1128/AAC.02014-16


Clustering of PCOS-like traits in naturally hyperandrogenic female rhesus monkeys

Steroid hormones were separated and quantified using high-performance liquid chromatography followed by tandem mass spectrometry (HPLC-MS/MS).   The lower detection limits were: androstenedione (A4), 0.1 ng/mL; cortisol and dehydroepiandrosterone (DHEA), 0.5 ng/mL; corticosterone, 11-deoxycortisol and deoxycorticosterone (DOC), 0.05 ng/mL; estradiol (E2) and estrone, 5 pg/mL; 17-hydroxyprogesterone (17-OHP) and progesterone, 0.2 ng/mL and Testosterone (T), 0.02 ng/mL.

Abbott DH, Rayome BH, Dumesic DA, et al. Hum Reprod. 2017;32(4):923-936. doi:10.1093/humrep/dex036


Clindamycin Pharmacokinetics and Safety in Preterm and Term Infants

Clindamycin concentrations were quantified using a validated liquid chromatography-tandem mass spectrometry assay.   The lower limit of quantification was 50 ng/mL.

Gonzalez D, Delmore P, Bloom BT, et al. Antimicrob Agents Chemother. 2016;60(5):2888-2894. Published 2016 Apr 22. doi:10.1128/AAC.03086-15


High-Throughput Screening of Chemical Effects on Steroidogenesis Using H295R Human Adrenocortical Carcinoma Cells

Steroid hormones were quantified using high-performance liquid chromatography followed by tandem mass spectrometry (HPLC-MS/MS).   The lower detection limits varied depending upon analyte.   Steroid hormones were extracted from media samples using methyl tert-butyl ether (MTBE).   An extra derivatization with dansyl chloride was included for estrogen (estrone and estradiol) detection only.

Karmaus AL, Toole CM, Filer DL, Lewis KC, Martin MT. Toxicol Sci. 2016;150(2):323-332. doi:10.1093/toxsci/kfw002


Exposure of Female Rats to an Environmentally Relevant Mixture of Brominated Flame Retardants Targets the Ovary, Affecting Folliculogenesis and Steroidogenesis

Steroid hormones, including pregnenolone, progesterone, 17-OH pregnenolone, 17-OH progesterone, dihydroepiandrosterone, androstenedione, testosterone, and dihydrotestosterone (DHT), were measured in 100-μl serum samples by high-performance liquid chromatography system interfaced to an Agilent Triple Quad LC/MS.

Lefèvre PL, Berger RG, Ernest SR, et al. Biol Reprod. 2016;94(1):9. doi:10.1095/biolreprod.115.134452


VT-1161 Protects Immunosuppressed Mice from Rhizopus arrhizus var. arrhizus Infection

VT-1161 plasma levels were measured by liquid chromatography-tandem mass spectrometry (LC/MS-MS).

Gebremariam T, Wiederhold NP, Fothergill AW, et al. Antimicrob Agents Chemother. 2015;59(12):7815-7817. doi:10.1128/AAC.01437-15


Evaluation of VT-1161 for Treatment of Coccidioidomycosis in Murine Infection Models

VT-1161 was extracted from plasma samples with methyl tert-butyl ether.   Samples were analyzed using high-performance liquid chromatography with tandem mass spectrometry using electrospray ionization.

Shubitz LF, Trinh HT, Galgiani JN, et al. Antimicrob Agents Chemother. 2015;59(12):7249-7254. doi:10.1128/AAC.00593-15


Efficacy of the Clinical Agent VT-1161 against Fluconazole-Sensitive and -Resistant Candida albicans in a Murine Model of Vaginal Candidiasis

VT-1161 was extracted from plasma samples with methyl tert-butyl ether.   Samples (plasma and vaginal tissues) were analyzed using high-performance liquid chromatography with tandem mass spectrometry using electrospray ionization.

Garvey EP, Hoekstra WJ, Schotzinger RJ, Sobel JD, Lilly EA, Fidel PL Jr. Antimicrob Agents Chemother. 2015;59(9):5567-5573. doi:10.1128/AAC.00185-15


Safety and Pharmacokinetics of Lisinopril in Pediatric Kidney Transplant Recipients

The concentration of lisinopril in plasma and urine was measured using high-pressure liquid chromatography–tandem mass spectrometry (HPLC-MS/MS).   For plasma, the lower limit of quantification was 0.5 ng/mL, and for urine the lower limit of quantification was 50 ng/mL.

Trachtman H, Frymoyer A, Lewandowski A, et al. Clin Pharmacol Ther. 2015;98(1):25-33. doi:10.1002/cpt.127


Simultaneous Determination of Trimethoprim and Sulfamethoxazole in Dried Plasma and Urine Spots

A precise, accurate and reproducible HPLC–MS/MS method was validated and applied to simultaneously quantify trimethoprim-sulfamethoxazole in dried plasma spots and dried urine spots samples collected in an opportunistic pediatric study.   The LLOQ for trimethoprim was 100 ng/mL in dried plasma spots and 500 ng/mL in dried urine spots samples; for sulfamethoxazole, the LLOQ was 1000 ng/mL for both matrices.

Gonzalez D, Melloni C, Poindexter BB, et al. Bioanalysis. 2015;7(9):1137-1149. doi:10.4155/bio.15.38


Developmental Programming: Exposure to Testosterone Excess Disrupts Steroidal and Metabolic Environment in Pregnant Sheep

Plasma concentrations of androstenedione, cortisol, dehydroepiandrosterone (DHEA), deoxycorticosterone (DOC), 11-deoxycortisol, estradiol, estrone, pregnenolone, 17α-OH-pregnenolone, 17α-OH-progesterone, and T were assayed in a subset of maternal samples (those bearing female fetuses, n = 6/group) collected at day 90 and the corresponding fetal samples using HPLC/mass spectrometry-mass spectrometry.

B. Abi Salloum, A. Veiga-Lopez, D. H. Abbott, C. F. Burant, and V. Padmanabhan corresponding author. Endocrinology. 2015 Jun; 156(6): 2323–2337. Published online 2015 Mar 12. doi: 10.1210/en.2014-2006 PMCID: PMC4430607 PMID: 25763641


VT-1161 Dosed Once Daily or Once Weekly Exhibits Potent Efficacy in Treatment of Dermatophytosis in a Guinea Pig Model

Collected samples (plasma, skin and hair) were analyzed using liquid chromatography-tandem mass spectrometry (LC/MS-MS) with electrospray ionization following extraction with methyl tert-butyl ether (MTBE).

Garvey EP, Hoekstra WJ, Moore WR, Schotzinger RJ, Long L, Ghannoum MA. Antimicrob Agents Chemother. 2015;59(4):1992-1997. doi:10.1128/AAC.04902-14


The Clinical Candidate VT-1161 Is a Highly Potent Inhibitor of Candida albicans CYP51 but Fails To Bind the Human Enzyme

In vitro ADME CYP2C9, CYP2C19, and CYP3A4 assays.

Warrilow AG, Hull CM, Parker JE, et al. Antimicrob Agents Chemother. 2014;58(12):7121-7127. doi:10.1128/AAC.03707-14


Use of Opportunistic Clinical Data and a Population Pharmacokinetic Model to Support Dosing of Clindamycin for Premature Infants to Adolescents

Clindamycin in plasma was quantified using a validated liquid chromatography-tandem spectrometry (LC-MS/MS) assay.   The validation range for the assay was 50–50,000 ng/mL.

Gonzalez D, Melloni C, Yogev R, et al. Clin Pharmacol Ther. 2014;96(4):429-437. doi:10.1038/clpt.2014.134


Characterization of the Population Pharmacokinetics of Ampicillin in Neonates Using an Opportunistic Study Design

Ampicillin concentrations were determined using a validated bioanalytical high-pressure liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay.   The validated range of this method for ampicillin based on 10 μLs of human plasma was 0.05 to 50 μg/mL.

Tremoulet A, Le J, Poindexter B, et al. Antimicrob Agents Chemother. 2014;58(6):3013-3020. doi:10.1128/AAC.02374-13


Synthesis, metabolic stability and antiviral evaluation of various alkoxyalkyl esters of cidofovir and 9-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]adenine

Test articles were incubated in Liver S9 fractions at 37 °C.   Samples were pulled from the incubation mixture at specified time points (0 to 90 minutes) and added to a solution of 1% ammonium hydroxide in N-propyl alcohol.   The amount of test article in each sample was quantified by HPLC/MS/MS.

Ruiz J, Beadle JR, Buller RM, et al. Bioorg Med Chem. 2011;19(9):2950-2958. doi:10.1016/j.bmc.2011.03.034


Development of hexadecyloxypropyl tenofovir (CMX157) for treatment of infection caused by wild-type and nucleoside/nucleotide-resistant HIV

Analyses of the PBMC samples to determine concentrations of the nucleotide analog TFV and anabolites TFV-MP and TFV-PP were performed utilizing high-performance liquid chromatography (HPLC) with tandem mass spectrometric detection (MS/MS).   TFV, TFV-MP, and TFV-PP were separated by gradient, reverse-phase, ion-pairing chromatography and detected by positive-ion electrospray.

Lanier ER, Ptak RG, Lampert BM, et al. Antimicrob Agents Chemother. 2010;54(7):2901-2909. doi:10.1128/AAC.00068-10