Aspirin pharmacokinetics and pharmacodynamics through gestation.

BACKGROUND: Low dose aspirin is recommended for prevention of preeclampsia, however there is not consensus on the appropriate dose. Pregnancy specific changes have the potential to impact the pharmacology of aspirin in pregnancy, however there are very limited studies on aspirin pharmacokinetics in pregnancy and none linking pharmacokinetics (PK, drug dose and drug level) to pharmacodynamics (PD, drug dose and physiologic response) in pregnancy. As a result, we do not have a good understanding of the pharmacologic response to aspirin in pregnancy, which has important implications for clinical efficacy. We sought to describe the PK and PD of aspirin through pregnancy and to identify individual covariates that impacted aspirin PK/PD. OBJECTIVE: We sought to describe the PK and PD of aspirin through pregnancy (first and third trimester), to identify covariates that significantly impact aspirin PK and to identify the relationship between aspirin PK and PD. STUDY DESIGN: This is a prospective study of patients at high risk for preeclampsia recommended to take 81 mg aspirin daily. This study involved 3 visits as follows: (1) baseline, first trimester (10-16 weeks of gestation) 6-hour PK visit, done before initiation of aspirin; (2) follow-up 1: 2 to 4 weeks after aspirin initiation; and (3) follow-up 2: third trimester 6-hour PK visit (28-32 weeks of gestation). The following were assessed at each visit: weight or body mass index, platelet function analysis-100 (Siemens), urinary thromboxane B2, serum thromboxane B2, and plasma salicylic acid. The PK visits consisted of blood work done at baseline (predose), administration of 81 mg nonenteric coated aspirin, and then plasma blood level of salicylic acid assessed at 30 minutes and then hourly 1 to 6 hours after dose. Pearson correlation and multivariable regression were used to identify associations between parameters and identify relevant covariates. Log-adjusted values were used for regression analysis. P<.05 was considered statistically significant. RESULTS: Nineteen participants were included with first trimester data, and 16 with third trimester data. There was no statistically significant change in mean PK parameters between the first and third trimester, although there was a trend to lower peak concentration in the third than in the first trimester (P=.08). In multivariable regression, baseline obesity and current body mass index as a continuous measures were negatively associated with log-adjusted peak salicylic acid concentration (-0.28 [-0.46 to -0.11], P=.003 and -0.02 [-0.03 to -0.009], P=.001, respectively) and log-adjusted plasma salicylic acid area under the curve 0 to 6 hours postdose (-0.25 [-0.45 to 0.05], P=.02, -0.04 [-0.07 to -0.01], P=.008 respectively). There was a significant decrease in urinary thromboxane 2 to 4 weeks after aspirin initiation compared with baseline, which correlated with a concomitant increase in platelet function analysis-100 closure time. In multivariable regression model, there was a strong association between plasma salicylic acid concentration (area under the curve 0-6 hours postdose) and urinary thromboxane (B=-3.12 [-5.38 to -1.04], P=.006), and with urinary thromboxane suppression and platelet inhibition, platelet function analysis-100 (-0.23 [-0.31 to -0.14], P<.001). With progressive thromboxane suppression, platelet inhibition (platelet function analysis-100 closure time) increased. Individual comorbidities, including weight, hypertension, and pregestational diabetes (Type I or II), also impacted aspirin response. CONCLUSION: We have demonstrated the relationship between individual factors, plasma concentrations of salicylic acid, thromboxane suppression, and platelet inhibition at a single dose (81 mg) of aspirin taken through pregnancy. Our findings suggest that dose modification of aspirin in pregnancy may help to achieve the optimal response. Our results may be used to facilitate computational modeling to identify optimal dosing, taking into consideration individual factors.

Improved Tumor Control Following Radiosensitization with Ultrasound-Sensitive Oxygen Microbubbles and Tumor Mitochondrial Respiration Inhibitors in a Preclinical Model of Head and Neck Cancer.

Tumor hypoxia (oxygen deficiency) is a major contributor to radiotherapy resistance. Ultrasound-sensitive microbubbles containing oxygen have been explored as a mechanism for overcoming tumor hypoxia locally prior to radiotherapy. Previously, our group demonstrated the ability to encapsulate and deliver a pharmacological inhibitor of tumor mitochondrial respiration (lonidamine (LND)), which resulted in ultrasound-sensitive microbubbles loaded with O2 and LND providing prolonged oxygenation relative to oxygenated microbubbles alone. This follow-up study aimed to evaluate the therapeutic response to radiation following the administration of oxygen microbubbles combined with tumor mitochondrial respiration inhibitors in a head and neck squamous cell carcinoma (HNSCC) tumor model. The influences of different radiation dose rates and treatment combinations were also explored. The results demonstrated that the co-delivery of O2 and LND successfully sensitized HNSCC tumors to radiation, and this was also enhanced with oral metformin, significantly slowing tumor growth relative to unsensitized controls (p < 0.01). Microbubble sensitization was also shown to improve overall animal survival. Importantly, effects were found to be radiation dose-rate-dependent, reflecting the transient nature of tumor oxygenation.

Population pharmacokinetic and safety analysis of ropivacaine used for erector spinae plane blocks.

INTRODUCTION: Erector spinae plane blocks have become popular for thoracic surgery. Despite a theoretically favorable safety profile, intercostal spread occurs and systemic toxicity is possible. Pharmacokinetic data are needed to guide safe dosing. METHODS: Fifteen patients undergoing thoracic surgery received continuous erector spinae plane blocks with ropivacaine 150 mg followed by subsequent boluses of 40 mg every 6 hours and infusion of 2 mg/hour. Arterial blood samples were obtained over 12 hours and analyzed using non-linear mixed effects modeling, which allowed for conducting simulations of clinically relevant dosing scenarios. The primary outcome was the Cmax of ropivacaine in erector spinae plane blocks. RESULTS: The mean age was 66 years, mean weight was 77.5 kg, and mean ideal body weight was 60 kg. The mean Cmax was 2.5 ±1.1 mg/L, which occurred at a median time of 10 (7-47) min after initial injection. Five patients developed potentially toxic ropivacaine levels but did not experience neurological symptoms. Another patient reported transient neurological toxicity symptoms. Our data suggested that using a maximum ropivacaine dose of 2.5 mg/kg based on ideal body weight would have prevented all toxicity events. Simulation predicted that reducing the initial dose to 75 mg with the same subsequent intermittent bolus dosing would decrease the risk of toxic levels to <1%. CONCLUSION: Local anesthetic systemic toxicity can occur with erector spinae plane blocks and administration of large, fixed doses of ropivacaine should be avoided, especially in patients with low ideal body weights. Weight-based ropivacaine dosing could reduce toxicity risk. TRIAL REGISTRATION NUMBER: NCT04807504; clinicaltrials.gov.

Tumoral oxygenation and biodistribution of Lonidamine oxygen microbubbles following localized ultrasound-triggered delivery.

Prior work has shown that microbubble-assisted delivery of oxygen improves tumor oxygenation and radiosensitivity, albeit over a limited duration. Lonidamine (LND) has been investigated because of its ability to stimulate glycolysis, lactate production, inhibit mitochondrial respiration, and inhibit oxygen consumption rates in tumors but suffers from poor bioavailability. The goal of this work was to characterize LND-loaded oxygen microbubbles and assess their ability to oxygenate a human head and neck squamous cell carcinoma (HNSCC) tumor model, while also assessing LND biodistribution. In tumors treated with surfactant-shelled microbubbles with oxygen core (SE61O2) and ultrasound, pO2 levels increased to a peak 19.5 ± 9.7 mmHg, 50 s after injection and returning to baseline after 120 s. In comparison, in tumors treated with SE61O2/LND and ultrasound, pO2 levels showed a peak increase of 29.0 ± 8.3 mmHg, which was achieved 70 s after injection returning to baseline after 300 s (p < 0.001). The co-delivery of O2andLNDvia SE61 also showed an improvement of LND biodistribution in both plasma and tumor tissues (p < 0.001). In summary, ultrasound-sensitive microbubbles loaded with O2 and LND provided prolonged oxygenation relative to oxygenated microbubbles alone, as well as provided an ability to locally deliver LND, making them more appropriate for clinical translation.

Development and Preclinical Investigation of Physically Cross-Linked and pH-Sensitive Polymeric Gels as Potential Vaginal Contraceptives.

This study explored the development of cross-linked gels to potentially provide a physical barrier to vaginal sperm transport for contraception. Two types of gels were formulated, a physically cross-linked iota-carrageenan (Ci) phenylboronic acid functionalized hydroxylpropylmethyacrylate copolymer (PBA)-based (Ci-PBA) gel, designed to block vaginal sperm transport. The second gel was pH-shifting cross-linked Ci-polyvinyl alcohol-boric acid (Ci-PVA-BA) gel, designed to modulate its properties in forming a viscoelastic, weakly cross-linked transient network (due to Ci gelling properties) on vaginal application (at acidic pH of ~3.5-4.5) to a more elastic, densely cross-linked (due to borate-diol cross-linking) gel network at basic pH of 7-8 of seminal fluid, thereby acting as a physical barrier to motile sperm. The gels were characterized for dynamic rheology, physicochemical properties, and impact on sperm functionality (motility, viability, penetration). The rheology data confirmed that the Ci-PBA gel was formed by ionic interactions whereas Ci-PVA-BA gel was chemically cross-linked and became more elastic at basic pH. Based on the screening data, lead gels were selected for in vitro sperm functionality testing. The in vitro results confirmed that the Ci-PBA and Ci-PVA-BA gels created a barrier at the sperm-gel interface, providing sperm blocking properties. For preclinical proof-of-concept, the Ci-PBA gels were applied vaginally and tested for contraceptive efficacy in rabbits, demonstrating only partial efficacy (40-60%). Overall, the in vitro and in vivo results support the development and further optimization of cross-linked gels using commercially available materials as vaginal contraceptives.

Development of a Dual Drug-Loaded, Surfactant-Stabilized Contrast Agent Containing Oxygen.

Co-delivery of cancer therapeutics improves efficacy and encourages synergy, but delivery faces challenges, including multidrug resistance and spatiotemporal distribution of therapeutics. To address these, we added paclitaxel to previously developed acoustically labile, oxygen-core, surfactant-stabilized microbubbles encapsulating lonidamine, with the aim of developing an agent containing both a therapeutic gas and two drugs acting in combination. Upon comparison of unloaded, single-loaded, and dual-loaded microbubbles, size (~1.7 µm) and yield (~2 × 109 microbubbles/mL) (~1.7) were not statistically different, nor were acoustic properties (maximum in vitro enhancements roughly 18 dB, in vitro enhancements roughly 18 dB). Both drugs encapsulated above required doses calculated for head and neck squamous cell carcinoma, the cancer of choice. Interestingly, paclitaxel encapsulation efficiency increased from 1.66% to 3.48% when lonidamine was included. During preparation, the combination of single drug-loaded micelles gave higher encapsulation (µg drug/g microbubbles) than micelles loaded with either drug alone (lonidamine, 104.85 ± 22.87 vs. 87.54 ± 16.41), paclitaxel (187.35 ± 8.38 vs. 136.51 ± 30.66). In vivo intravenous microbubbles produced prompt ultrasound enhancement within tumors lasting 3-5 min, indicating penetration into tumor vasculature. The ability to locally destroy the microbubble within the tumor vasculature was confirmed using a series of higher intensity ultrasound pulses. This ability to locally destroy microbubbles shows therapeutic promise that warrants further investigation.

Stability of extemporaneously compounded 5-fluorouracil utilizing high performance liquid chromatography.

The goal of the current study is to determine stability of compounded 5-fluorouracil (5-FU) in Intravia™ bags and CADD™ cassettes stored up to 15 days under refrigeration (2-8°C) and room temperature (25°C with 60% relative humidity), with four different concentrations (20 mg/mL, 30 mg/mL, 40 mg/mL, and 50 mg/mL) and two diluents (0.9% sodium chloride and 5% dextrose). A stability-indicating high-performance liquid chromatography (HPLC) method was developed to analyze the 5-FU concentrations. The stability of compounded 5-FU infusions was investigated using this method. Two samples from each storage condition were assessed for stability on days 0, 4, 7, 10, and 15 as per United States Pharmacopeia (USP) guidelines. The assay of 5-FU was done utilizing a calibrated stability-indicating HPLC method. The stability-indicating HPLC assay showed 5-FU completely degraded within 1 hour in basic conditions. No cloudiness or color change was observed during the stability study. Precipitation was observed in the CADD™ cassettes at day 15 in both storage conditions and at day 10 in a single room-temperature CADD™ cassette for 40 mg/mL in 5% dextrose (D5W). HPLC assay revealed the infusions in CADD™ cassettes retained greater than 90% of the initial concentrations of 5-FU for 15 days stored at room temperature (25°C and 60% relative humidity) and for 10 days at refrigeration (2-8°C). Intravia™ bags retained stability through 15 days for all the compounded 5-FU concentrations and both the storage conditions. 5-FU infusions in both CADD™ cassettes and Intravia™ bags were stable for extendable periods in multiple concentrations compared to recommended guidelines for hospital use.

Randomized trial of prophylactic antibiotics vs. placebo after midshaft-to-distal hypospadias repair: the PROPHY Study.

BACKGROUND: Use of prophylactic antibiotics after stented hypospadias repair is very common, but most research has not identified any clinical benefits of this practice. Only one study has found that postoperative prophylaxis reduces symptomatic urinary tract infections (UTIs). Data from the same trial suggested that prophylaxis may also reduce urethroplasty complications. No studies on this subject have been placebo-controlled. OBJECTIVE: We performed a randomized, double-blind, placebo-controlled study to evaluate the effect of postoperative prophylactic antibiotics on the incidence of infection or urethroplasty complications after stented repair of midshaft-to-distal hypospadias. STUDY DESIGN: Boys were eligible for this multicenter trial if they had a primary, single-stage repair of mid-to-distal hypospadias with placement of an open-drainage urethral stent for an intended duration of 5-10 days. Participants were randomized in a double-blind fashion to receive oral trimethoprim-sulfamethoxazole or placebo twice daily for 10 days postoperatively. The primary outcome was a composite of symptomatic UTI, surgical site infection (SSI), and urethroplasty complications, including urethrocutaneous fistula, meatal stenosis, and dehiscence. Secondary outcomes included each component of the primary outcome as well as acute adverse drug reactions (ADRs) and C. difficile colitis. RESULTS: Infection or urethroplasty complications occurred in 10 of 45 boys (22%) assigned to receive antibiotic prophylaxis as compared with 5 of 48 (10%) who received placebo (relative risk [RR], 2.1; 95% confidence interval [CI], 0.8 to 5.8; p = 0.16). There were no significant differences between groups in symptomatic UTIs, SSIs, or any urethroplasty complications. Mild ADRs occurred in 3 of 45 boys (7%) assigned to antibiotics as compared with 5 of 48 (10%) given placebo (RR, 0.6; 95% CI, 0.2 to 2.5; p = 0.72). There were no moderate-to-severe ADRs, and no patients developed C. difficile colitis. CONCLUSIONS: In this placebo-controlled trial of 93 patients, prophylactic antibiotics were not found to reduce infection or urethroplasty complications after stented mid-to-distal hypospadias repair. The study did not reach its desired sample size and was therefore underpowered to independently support a conclusion that prophylaxis is not beneficial. However, the result is consistent with most prior research on this subject. GOV IDENTIFIER: NCT02096159.

Stability-indicating HPLC method to determine the stability of extemporaneously prepared vancomycin oral solution cups.

PURPOSE: To determine the stability of compounded sweetened vancomycin oral formulations in plastic unit dose cups stored up to 180 days under 2 temperature conditions: refrigeration (2°C-6°C) and room temperature (25°C with 60% relative humidity). METHODOLOGY: A stability-indicating high-performance liquid chromatography (HPLC) method was developed to analyze vancomycin in the presence of degradation peaks. The stability of extemporaneously compounded vancomycin solution stored in oral unit dose cups was investigated using this method. The tested vancomycin oral solutions were compounded formulations of 125 mg/2.5 mL and 500 mg/10 mL. Three oral unit dose cups from each storage condition were withdrawn and assessed for stability on days 0, 3, 7, 15, 22, 30, 90, 120, 150, and 180 as per United States Pharmacopeia guidelines. The assay of vancomycin was carried out by using a calibrated stability-indicating HPLC method. RESULTS: The stability-indicating HPLC assay showed that vancomycin completely degraded within 2 hours when exposed to highly acidic or basic pH conditions. No precipitation, cloudiness, or color changes were observed during the study under either temperature condition. The HPLC assay revealed that vancomycin oral solution cups retained greater than 90% of the initial concentrations of vancomycin for 30 days when stored at room temperature (25°C and 60% relative humidity) and for 180 days with refrigeration (2°C-6°C). CONCLUSION: Vancomycin oral formulations were stable for long-term storage periods beyond those specified in manufacture guidelines. Our data suggests the extended stability of vancomycin oral solutions compounded for hospital use can be extended.

Longitudinal evaluation of azithromycin and cytokine concentrations in amniotic fluid following one-time oral dosing in pregnancy.

To utilize noninvasive collection of amniotic fluid in the setting of preterm premature rupture of membranes (PPROMs) to report the time concentration profile of azithromycin in amniotic fluid over 7 days from a single dose, and evaluate the correlation between azithromycin concentration and inflammatory markers in amniotic fluid. Prospective cohort study of five pregnant patients admitted with PPROMs and treated with a single 1 g oral azithromycin dose. Amniotic fluid was collected from pads and used to quantify azithromycin concentration as well as TNFa, IL-1a, IL-1b, IL-6, IL-8, and IL-10 concentrations. Primary outcome was time/concentration profile of azithromycin in amniotic fluid. Secondary outcome included correlation between azithromycin concentration and cytokine concentrations. Five patients were enrolled. Mean gestational age on admission with PPROM was 27.5 ± 2.3 weeks with a median latency of 7 days (interquartile range [IQR] = 4-13). A median of two samples/day (IQR = 1-3) were collected per participant. Azithromycin was quantified in duplicate; intra-assay coefficient of variation was 17%. Azithromycin concentration was less than 60 ng/ml after day 3. Azithromycin concentration was positively correlated with IL-8 (r = 0.38, p = 0.03), IL1a (r = 0.39, p = 0.03), and IL-1b (r = 0.36, p = 0.04) in amniotic fluid. Azithromycin is detectable in amniotic fluid over 7 days from a single 1 g maternal dose, however, it is not sustained over the range of minimum inhibitory concentration for common genitourinary flora. Based on correlation with specific cytokines, azithromycin penetration in amniotic fluid may relate to maternal monocyte concentration in amniotic fluid in the setting of PPROM.

Pharmacometric dose optimization of buprenorphine in neonatal opioid withdrawal syndrome.

Results from Blinded Buprenorphine OR Neonatal morphine solution (BBORN), a previous phase III trial in infants with neonatal opioid withdrawal syndrome (NOWS), demonstrated that sublingual buprenorphine resulted in a shorter duration of treatment and shorter length of hospital stay than the comparator, oral morphine. Objectives of Buprenorphine Pharmacometric Open Label Research study of Drug Exposure (BPHORE), a new trial with buprenorphine in a similar population, were to (1) optimize initial dose, up-titration to achieve symptom control and weaning steps of pharmacologic treatment and (2) investigate safety of the revised regimen. A pharmacodynamic model linked buprenorphine exposure to NOWS symptom scores. Adaptive dose regimens were simulated using BBORN results to compare dosing regimens for times to stabilization, weaning, and cessation. A clinical trial using model informed doses (BPHORE), was conducted. Simulations indicated benefits in time to stabilization and weaning when up-titration rates increased to 30%. Stabilization time was not greatly impacted by the starting dose. Time to wean and time to cessation were dose dependent. A weaning rate of 25% shortened time to cessation. Ten infants were enrolled in BPHORE using buprenorphine starting dose of 24 µg/kg/day, 33% titration, and 15% wean rate. Five subjects required adjuvant therapy. Half-maximal effective concentration (EC50 ) values indicated maximum buprenorphine doses did not generate maximal effect size, suggesting potential efficacy of a further increased dose if a goal was to reduce the use of adjunct agents. Simulations indicated that further benefits can be gained by increasing starting doses of buprenorphine and increasing wean rates. Use of a model-based analysis to provide focused guidelines for care can be used with goals of reducing treatment time and hospital stays in infants with NOWS.

Stability-indicating LC-MS Method for Determination of Stability of Extemporaneously Compounded Buprenorphine Oral Syringes for Neonatal Abstinence Syndrome.

OBJECTIVE: In the hospital settings, buprenorphine is used for the treatment of patients with neonatal abstinence syndrome. It is extemporaneously compounded and stored in oral plastic syringes. However, limited information exists about the stability of buprenorphine and its compounded formulations when stored under specific conditions. Hence, we developed a stability-indicating high-performance liquid chromatography-mass spectrometry (LC-MS) method to analyze the stability of buprenorphine over time. METHODS: A stability-indicating LC-MS method was developed to map the potential degradation peaks of buprenorphine when exposed to acidic, basic, and oxidative conditions. This method was used to study the stability of compounded buprenorphine oral syringes stored under refrigeration (2°C-8°C) and room temperature (25°C ± 2°C with 60% relative humidity). Syringes from each storage condition were assessed for stability using pH meter and stability-indicating LC-MS assay for 30 days. RESULTS: Buprenorphine gets completely degraded in the presence of acid at the end of 1 hour of exposure. Various degradation peaks were identified using LC-MS assay for buprenorphine under acidic, basic, and peroxide conditions. Stability study of oral buprenorphine syringes showed no precipitation, cloudiness, or color change during this study at all storage conditions. The LC-MS assay revealed that buprenorphine oral syringes retained greater than 90% of the initial concentrations for 30 days. CONCLUSIONS: Highly sensitive stability-indicating LC-MS method was developed for studying the stability of extemporaneously compounded buprenorphine oral syringes. This study demonstrates that buprenorphine extemporaneous formulation prepared according to the manufacturers' recommendations is stable under refrigerated or room temperature conditions for 30 days in oral plastic syringes.

Symptoms of gluten ingestion in patients with non-celiac gluten sensitivity: A randomized clinical trial.

OBJECTIVES: Non-celiac gluten sensitivity (NCGS) is the presence of symptoms induced by gluten and relieved by a gluten-free diet (GFD) in patients without celiac disease or wheat allergy. Studies are mixed as to whether gluten is the main symptom trigger in patients with NCGS. Gluten immunogenic peptides (GIPs) in stool and urine are novel methods to monitor GFD compliance. Few studies have investigated their use in patients with NCGS. The aim of this study was to assess whether patients with NCGS have increased symptoms with gluten ingestion and to assess compliance with the GFD using stool and urine GIPs. METHOD: This was a prospective, randomized, double-blinded crossover trial evaluating symptoms in patients with NCGS. Thirty patients with NCGS and 43 healthy controls were placed on a GFD. Patients received 0.5 or 2 g/d of gluten for 7 d each. The remaining weeks, they received placebo for a total of 4 wk. Symptoms were evaluated weekly using the Celiac Symptom Index (CSI). Urine and stool samples were collected weekly and measured for the detection of GIPs to detect exposure to gluten. RESULTS: There was no difference in symptom severity within the NCGS group whether receiving placebo or gluten (32.69 versus 31.54, P = 0.64). Patients with NCGS had significantly higher CSI scores at baseline than healthy controls. Patients with NCGS were less likely to have stool and urine GIPs than healthy patients. CONCLUSION: Patients with NCGS were more adherent to the GFD based on stool and urine GIP results. Patients with NCGS had increased symptom severity at baseline compared with healthy controls. Neither group had significantly increased symptoms after ingestion of gluten.

LC-MS based stability-indicating method for studying the degradation of lonidamine under physical and chemical stress conditions.

BACKGROUND AND PURPOSE: Lonidamine is a hexokinase II inhibitor, works as an anticancer molecule, and is extensively explored in clinical trials. Limited information prevails about the stability-indicating methods which could determine the forced degradation of lonidamine under stressed conditions. Hence, we report the use of a rapid, sensitive, reproducible, and highly accurate liquid chromatography and mass spectrometry method to analyze lonidamine degradation. EXPERIMENTAL APPROACH: The Xbridge BEH shield reverse phase C18 column (2.5 µm, 4.6 × 75 mm) using isocratic 50:50 water: acetonitrile with 0.1% formic acid can detect lonidamine with help of mass spectrometer in tandem with an ultraviolet (UV) detector at 260 nm wavelength. FINDINGS/ RESULTS: A linear curve with r2 > 0.99 was obtained for tandem liquid chromatography-mass spectrometry (LC-MS)-UV based detections. This study demonstrated (in the present set up of isocratic elution) that LC-MS based detection has a relatively high sensitivity (S/N (10 ng/mL): 220 and S/N (20 ng/mL): 945) and accuracy at lower detection and quantitation levels, respectively. In addition to developing the LC-MS method, we also report that the current method is stability-indicating and shows that lonidamine gets degraded over time under all three stress conditions; acidic, basic, and oxidative. CONCLUSION AND IMPLICATIONS: LC-MS based quantitation of lonidamine proved to be a better method compared to high-performance liquid chromatography (HPLC)-UV detections for mapping lonidamine degradation. This is the first report on the stability-indicating method for studying the forced degradation of lonidamine using LC-MS method.

Metabolic plasticity imparts erlotinib-resistance in pancreatic cancer by upregulating glucose-6-phosphate dehydrogenase.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant forms of cancer. Lack of effective treatment options and drug resistance contributes to the low survival among PDAC patients. In this study, we investigated the metabolic alterations in pancreatic cancer cells that do not respond to the EGFR inhibitor erlotinib. We selected erlotinib-resistant pancreatic cancer cells from MiaPaCa2 and AsPC1 cell lines. Metabolic profiling of erlotinib-resistant cells revealed a significant downregulation of glycolytic activity and reduced level of glycolytic metabolites compared to the sensitive cells. The resistant cells displayed elevated expression of the pentose phosphate pathway (PPP) enzymes involved in ROS regulation and nucleotide biosynthesis. The enhanced PPP elevated cellular NADPH/NADP+ ratio and protected the cells from reactive oxygen species (ROS)-induced damage. Inhibition of PPP using 6-aminonicotinamide (6AN) elevated ROS levels, induced G1 cell cycle arrest, and sensitized resistant cells to erlotinib. Genetic studies identified elevated PPP enzyme glucose-6-phosphate dehydrogenase (G6PD) as an important contributor to erlotinib resistance. Mechanistically, our data showed that upregulation of inhibitor of differentiation (ID1) regulates G6PD expression in resistant cells thus contributing to altered metabolic phenotype and reduced response to erlotinib. Together, our results highlight an underlying role of tumor metabolism in PDAC drug response and identify G6PD as a target to overcome drug resistance.

Heat Shock Protein 90 (Hsp90)-Inhibitor-Luminespib-Loaded-Protein-Based Nanoformulation for Cancer Therapy.

Drugs targeting heat shock protein 90 (Hsp90) have been extensively explored for their anticancer potential in advanced clinical trials. Nanoformulations have been an important drug delivery platform for the anticancer molecules like Hsp90 inhibitors. It has been reported that bovine serum albumin (BSA) nanoparticles (NPs) serve as carriers for anticancer drugs, which have been extensively explored for their therapeutic efficacy against cancers. Luminespib (also known as NVP-AUY922) is a new generation Hsp90 inhibitor that was introduced recently. It is one of the most studied Hsp90 inhibitors for a variety of cancers in Phase I and II clinical trials and is similar to its predecessors such as the ansamycin class of molecules. To our knowledge, nanoformulations for luminespib remain unexplored for their anticancer potential. In the present study, we developed aqueous dispensable BSA NPs for controlled delivery of luminespib. The luminespib-loaded BSA NPs were characterized by SEM, TEM, FTIR, XPS, UV-visible spectroscopy and fluorescence spectroscopy. The results suggest that luminespib interacts by non-covalent reversible interactions with BSA to form drug-loaded BSA NPs (DNPs). Our in vitro evaluations suggest that DNP-based aqueous nanoformulations can be used in both pancreatic (MIA PaCa-2) and breast (MCF-7) cancer therapy.

Compatibility of treprostinil sodium and dopamine hydrochloride during simulated Y-site administration.

PURPOSE: To evaluate the physical and chemical compatibilities of treprostinil sodium and dopamine hydrochloride. METHODS: Treprostinil sodium (4,000, 76,000, and 500,000 ng/mL) were mixed with dopamine hydrochloride (0.6, 3.2, 6, and 40 mg/mL). Samples were obtained at hours 0, 1, 2, and 4 for physical compatibility and chemical stability testing. Physical compatibility was assessed by visual examination and measurements of turbidity and pH. Drug concentrations were assessed using stability-indicating liquid chromatography mass spectrophotometry (LCMS) for treprostinil sodium and stability-indicating high-performance liquid chromatography (HPLC) for dopamine hydrochloride. RESULTS: Treprostinil sodium 4,000 and 76,000 ng/mL, when mixed with dopamine hydrochloride 0.6, 3.2, 6, and 40 mg/mL, were stable for 4 hours. Treprostinil sodium 500,000 ng/mL was stable when mixed with dopamine hydrochloride 0.6 mg/mL for 4 hours, but when mixed with dopamine hydrochloride 3.2, 6, and 40 mg/mL, significant precipitation was seen. CONCLUSION: Treprostinil sodium 4,000 and 76,000 ng/mL were stable for 4 hours during simulated Y-site coadministration with dopamine hydrochloride 0.6, 3.2, 6, and 40 mg/mL. Treprostinil sodium 500,000 ng/mL is stable when mixed with dopamine hydrochloride 0.6 mg/mL.

Expression of Tryptophan 2,3-Dioxygenase in Metastatic Uveal Melanoma.

Uveal melanoma (UM) is the most common primary eye malignancy in adults and up to 50% of patients subsequently develop systemic metastasis. Metastatic uveal melanoma (MUM) is highly resistant to immunotherapy. One of the mechanisms for resistance would be the immune-suppressive tumor microenvironment. Here, we have investigated the role of tryptophan 2,3-dioxygenase (TDO) in UM. Both TDO and indoleamine 2,3-dioxygenase (IDO) catalyze tryptophan and produce kynurenine, which could cause inhibition of T cell immune responses. We first studied the expression of TDO on tumor tissue specimens obtained from UM hepatic metastasis. High expression of TDO protein was confirmed in all hepatic metastasis. TDO was positive in both normal hepatocytes and the tumor cells with relatively higher expression in tumor cells. On the other hand, IDO protein remained undetectable in all of the MUM specimens. UM cell lines established from metastasis also expressed TDO protein and increasing kynurenine levels were detected in the supernatant of MUM cell culture. In TCGA database, higher TDO2 expression in primary UM significantly correlated to BAP1 mutation and monosomy 3. These results indicate that TDO might be one of the key mechanisms for resistance to immunotherapy in UM.

Simultaneous quantitative LC-MS method of ketamine, midazolam and their metabolites (dehydronorketamine, norketamine and 1hydroxymidazolam) for its application in patients on extracorporeal membrane oxygenation (ECMO) therapy.

Ketamine (Ket) and midazolam (MDZ) are commonly administered drugs in the intensive care setting for analgesia and sedation. Ket and MDZ are metabolized to dehydro-norketamine (DHNK), nor-ketamine (NK) and 1-hydroxy midazolam (1HMDZ). Limited studies evaluating their pharmacokinetics exists in patients on extracorporeal membrane oxygenation (ECMO) therapy. Therefore, we developed a quantitative, high-performance liquid chromatography-mass spectrometry (with single ion monitoring) method to simultaneously detect Ket, MDZ and their (DHNK, NK and 1HMDZ) metabolites in human plasma. Considerable sensitivity was obtained for the analytes using a C18 HILIC column operated by a high-performance liquid chromatography system coupled with a Thermo Exactive Orbitrap mass spectrometer. Calibration curves were developed for analyte molecules (n = 5) in the presence of carbamazepine (CBZ) as an internal standard. The lower limits of quantitation (LLOQ) for Ket and MDZ were 20 and 10 ng/mL, respectively with the LLOQ for DHNK, NK and 1HMDZ at 470, 320 and 150 ng/ml. Moreover, the percent coefficient of variance and precision for inter- and intra-day runs were within the standards set forth by the ICH and FDA guidelines. This method is sensitive and has been successfully applied to an ongoing pharmacokinetic study in patients on ECMO therapy.

Pharmacokinetics of Ketamine at Dissociative Doses in an Adult Patient With Refractory Status Asthmaticus Receiving Extracorporeal Membrane Oxygenation Therapy.

PURPOSE: First-line management of severe asthma exacerbations include the use of inhaled short-acting ß-agonists, anticholinergics, and systemic corticosteroids. Continuous intravenous ketamine given at dissociative doses may be a pharmacologic option in patients who are intubated with life-threatening severe bronchospasm unresponsive to standard therapy. We describe the case of a 44-year-old man admitted to the intensive care unit for status asthmaticus requiring intubation and mechanical ventilation. METHODS: The patient developed severe refractory hypercapnic respiratory failure necessitating additional respiratory support with veno-venous extracorporeal membrane oxygenation (ECMO) therapy. Ketamine treatment was initiated at 0.5 mg/kg/h continuous infusion on the day of admission for pain control and required up-titration to 2 mg/kg/h by intensive care unit day 4 for bronchodilation. Whole blood samples were obtained for pharmacokinetic analysis of ketamine during ECMO. FINDINGS: The plasma concentration at steady state was 1018.7 ng/mL, with an estimated clearance of 1.96 L/kg/h after up-titration. The Vd was 14.18 L/kg, the ke was 0.14 hr-1, and the t½ was 5 hours. IMPLICATIONS: Compared with healthy adults, there was a 6.5-fold increase in the Vd. However, the Vd was similar compared with critically ill patients not receiving ECMO. Further studies should focus on the effect of ECMO on ketamine pharmacokinetic properties.