Establishment of a research pharmacy to support Ebola clinical research in Liberia.

OBJECTIVE: This article describes the establishment of a research pharmacy to support the Partnership for Research on Ebola Vaccines in Liberia (PREVAIL) vaccine study for Ebola virus disease. SETTING: This article describes the establishment of the pharmacy element to support the overall research program during an Ebola outbreak in Monrovia, Liberia, in 2014 and 2015. PRACTICE INNOVATION: The need for the rapid establishment of infrastructure to support the Liberia-United States joint clinical research partnership in response to the emerging Ebola virus disease provided the opportunity for collaboration among Liberian and U.S. pharmacists. PRACTICE DESCRIPTION: Resource austere and research naïve. EVALUATION: Research pharmacy prepared and randomized 1500 vaccinations in support of PREVAIL. RESULTS: Experiences of the Liberian and U.S. pharmacists involved in the program are described. CONCLUSION: The partnership was successful in the conduct of the study. More importantly, the capacity for Liberian pharmacists to support clinical research was established. In addition, the U.S. team learned several important lessons that will help prepare them for responding to research needs in future infectious disease outbreaks.

Determination of desoxyepothilone B in nude mice plasma by liquid-liquid extraction and reversed-phase high-performance liquid chromatography.

A novel reversed-phase high-performance liquid chromatographic (HPLC) method has been established for the determination of a newly developed anti-cancer agent desoxyepothilone B (dEpo B) in nude mice plasma. The sample preparation involved deproteination of 200 microl of plasma sample first, followed by liquid-liquid extraction of the resultant supernatant with chloroform. The compound taxol was used as the internal standard. Chromatographic separations were carried out on a 250 mm x 4.6 mm Zorbax SB-phenyl column with acetonitrile-0.25% orthophosphoric acid (50/50, v/v) as mobile phase and UV detection at 250 nm. For dEpo B and taxol at the concentration level of 10 microg/ml in nude mice plasma, the absolute extraction recoveries were 85.3 and 87.2%, respectively. The linear quantification range of the method was 0.1-100 microg/ml in nude mice plasma with linear correlation coefficients greater than 0.999. The within-day and between-day relative standard deviations (R.S.D.s) for dEpo B at 0.5, 2.5 and 10 microg/ml levels in nude mice plasma fell in the range of 2.8-4.8 and 1.5-4.6%, and the within-day and between-day recoveries were in the range of 96.5-101.7 and 97.7-101.2%, respectively.

Preclinical pharmacology of 2-methoxyantimycin A compounds as novel antitumor agents.

PURPOSE: The present study was designed to determine pharmacological and biochemical properties of 2-methoxyantimycin A analogs (OMe-A1, OMe-A2, OMe-A3, and OMe-A5), which are novel antitumor compounds, and provide a basis for future pharmaceutical development, preclinical evaluation, and clinical trials. METHODS: A high-performance liquid chromatography (HPLC) method was established and employed to assess the biostability of these analogs and to determine their pharmacokinetic properties in mice and rats. RESULTS: In vitro biostability of the 2-methoxyantimycin analogs was esterase-dependent, compound-dependent, and species-dependent. In the absence of esterase inhibitors, all of the analogs were relatively unstable. Stability was greater, however, in human and dog plasma than in rat and mouse plasma. In the presence of esterase inhibitors, OMe-A1 was stable at 37 degrees C for 60 min in mouse and rat plasma, moderately stable in human plasma, and unstable in dog plasma. OMe-A2 was generally stable in all types of plasma. OMe-A3 was stable in dog and rat plasma, but not in human or mouse plasma. OMe-A5 was stable in human and dog plasma, but not in mouse or rat plasma. Each of these analogs was highly bound to plasma proteins. Of S9 fractions from four species, human S9 was least efficient in metabolizing OMe-A3. Following an intravenous dose of OMe-A1 in mice, plasma levels decreased rapidly, with an initial half-life of 2.7 min and a terminal half life of 34 min. Following an intraperitoneal dose in mice, plasma levels decreased less rapidly with a terminal half-life of 215 min. Following an intravenous dose of OMe-A1 or OMe-A3 in rats, plasma levels decreased more rapidly with initial half-lives of about 1.0 min. At an equivalent dose, OMe-A3 had a faster clearance than OMe-A1. CONCLUSIONS: For 2-methoxyantimycin A analogs, species differences in biostability, metabolism, and pharmacokinetics may be pertinent in assessing their pharmacological and toxicological profiles and antitumor activity in humans.

Preclinical pharmacology of epothilone D, a novel tubulin-stabilizing antitumor agent.

PURPOSE: To determine, for various species, the pharmacological and biochemical properties of epothilone D (EpoD) that are relevant in establishing an appropriate animal model for further evaluation of this promising antitumor agent. METHODS: A method involving high-performance liquid chromatography (HPLC) was developed and used to assess the stability and protein binding of EpoD in plasma from various species, its metabolism by various S9 fractions, and its pharmacokinetics in mice. RESULTS: EpoD was stable in dog and human plasma. In plasma from other species, stability decreased in the order: hamster > mouse > guinea pig > rat. EpoD was highly bound to proteins in dog and human plasma. In an evaluation of S9 fractions from mouse, rat, guinea pig, dog, and human, mouse S9 was most efficient in metabolizing EpoD. Following administration to CD2F1 mice, the initial half-lives for plasma elimination of EpoD were <5 min for an intravenous dose and <20 min for an intraperitoneal dose. CONCLUSIONS: The species differences in EpoD biostability and metabolism may have implications in assessing its antitumor activity and pharmacologic and toxicologic profiles in humans. Relative to humans, the mouse is not a good model for disposition of EpoD; the dog would be more appropriate.

Plasma and cellular pharmacology of 8-chloro-adenosine in mice and rats.

PURPOSE: The nucleoside 8-chloro-adenosine (8-Cl-Ado) is currently being developed for treatment of multiple myeloma and leukemias. Although accumulation of the phosphorylated drug product is known to occur within cell lines, its metabolic fate in plasma or circulating cells in animals is unclear. The purpose of the present study was to determine the pharmacology of 8-Cl-Ado in rodents through examination of plasma and cellular levels of parent drug and metabolites. In addition, we sought to determine whether an inhibitor of adenosine deaminase, 2'-deoxycoformycin (dCF), could enhance intracellular formation of 8-Cl-ATP by preventing degradation of 8-Cl-Ado to 8-Cl-inosine (8-Cl-Ino). METHODS: A validated HPLC assay permitted simultaneous determination of 8-Cl-Ado, 8-Cl-adenine (8-Cl-Ade), dCF, and 8-Cl-Ino. Radiolabeled cellular nucleotides were obtained from peripheral blood mononuclear cells (PBMC) of both mice and rats using a perchloric acid extraction procedure and were separated by HPLC. RESULTS: Stability of 8-Cl-Ado in the presence or absence of dCF was examined in fresh plasma from mice, rats and humans. Conversion of 8-Cl-Ado to 8-Cl-Ino was only marginally affected by coincubation with dCF. In CD(2)F(1) mice given 8-Cl-Ado i.p. at 100 mg/kg, there was rapid appearance in plasma of both 8-Cl-Ade and 8-Cl-Ino. The identities of the metabolites were confirmed by mass spectrometry. The plasma [(3)H]8-Cl-Ado concentration 1 h after drug injection was 1.3 micro M in mice while the intracellular levels of [(3)H]8-Cl-AMP and [(3)H]8-Cl-ATP were 1 m M and 350 micro M, respectively. Mice that had received dCF (2 mg/ml) 30 min prior to [(3)H]8-Cl-Ado had 27% less intracellular [(3)H]8-Cl-ATP in PBMC compared to mice without dCF pretreatment. The pharmacokinetics of 8-Cl-Ado were examined in greater detail in Sprague-Dawley rats. Animals were given [(3)H]8-Cl-Ado (42.5 mg/kg, i.v.) by itself or 30 min following injection of dCF (4 mg/kg). Mononuclear cells in mice accumulated 350 or 1200 micro M [(3)H]8-Cl-ATP 1 h after injection of either 50 or 100 mg [(3)H]8-Cl-Ado, respectively. The major metabolite in these cells was the monophosphate, which was four- to sevenfold higher in concentration than the triphosphate metabolite. In rats, [(3)H]8-Cl-AMP concentrations in PBMC were similar to those of the triphosphate metabolite which achieved a peak of 90 micro M 2 h after a bolus injection of 8-Cl-Ado (40 mg/kg). Cellular clearance of 8-Cl-ATP appeared to be slow: 24 h after injection of 8-Cl-Ado the cellular concentration of 8-Cl-ATP was still 40 micro M. CONCLUSIONS: The use of dCF did not significantly alter 8-Cl-ATP levels in PBMC and is not considered to be a useful therapeutic strategy. Even though a portion of 8-Cl-Ado is metabolically inactivated in plasma, high levels of cytotoxic 8-Cl-ATP accumulated intracellularly in these animals and were retained for a considerable length of time. Further development of 8-Cl-Ado is recommended.

Radiolabeled 2'-fluorodeoxyuracil-beta-D-arabinofuranoside (FAU) and 2'-fluoro-5-methyldeoxyuracil-beta -D-arabinofuranoside (FMAU) as tumor-imaging agents in mice.

PURPOSE: The purpose of the present study was to evaluate, in conjunction with the National Cancer Institute, the feasibility of using two thymidine analogs, 2'-fluorodeoxyuracil-beta-D-arabinofuranoside (FAU, NSC-678515) and 2'-fluoro-5-methyldeoxyuracil-beta-D-arabinofuranoside (FMAU, NSC-678516), as 18-fluorine-labeled positron emission tomography (PET) imaging agents. METHODS: The in vivo distribution and DNA incorporation of [2-(14)C]FAU, [2-(14)C]FMAU, and [2-(14)C]thymidine (as a control) were studied in SCID mice bearing human xenografts of T-cell leukemia CCRF-CEM. Levels of drug-associated radioactivity in blood, tumor and normal tissues including liver, kidneys, heart, lungs, spleen, brain, and skeletal muscle were determined. RESULTS: At 1 h after dosing, radioactivity from all three compounds was distributed in a generally nonspecific manner, except that spleen and tumor tissue had relatively high concentrations of radioactivity from [(14)C]thymidine. At 4 h after dosing, the concentrations of radioactivity from [(14)C]thymidine and [(14)C]FMAU were relatively high in spleen and tumor tissue, and that from [(14)C]FAU was highest in tumor tissue. The tumor/skeletal muscle concentration ratios were 2.25+/-0.69 and 3.07+/-0.42 for [(14)C]FAU and [(14)C]FMAU, respectively. At 24 h after dosing, only spleen and tumor tissues contained appreciable amounts of radioactivity from either compound. In tumor tissue, the levels of radioactivity from [(14)C]FMAU were two- to threefold greater than those from [(14)C]thymidine or [(14)C]FAU. Examination of purified genomic DNA from tumor, liver, kidneys, brain, and skeletal muscle showed that, at 24 h after dosing, only DNA from tumor tissue contained appreciable concentrations of radioactivity. Radioactivity from [(14)C]FMAU in tumor DNA was 45% greater than that from [(14)C]thymidine and about threefold greater than that from [(14)C]FAU. CONCLUSIONS: The extent of accumulation of [(14)C]FMAU in tumor tissue and incorporation into tumor DNA indicate that [(18)F]FMAU could be useful as a functional PET tumor-imaging agent.