Performance evaluation of the HPLC diode array and evaporative light scattering detection for the implementation of dose-banded gemcitabine infusion bags

BACKGROUND

Dose banding (DB) was used to optimise the individualisation of patient treatments with gemcitabine (Gem) in order to improve workload planning at the pharmacy of the University Hospital Centre of Besançon (UHCB). A new simple and fast high-performance liquid chromatographic (HPLC) method was also developed for the quantification of Gem without dilution of the infusion bags.

METHODS

Individual doses of Gem preparations were retrospectively analysed over a 1-year period to determine the frequency of prepared doses. Using a maximum gap of 7.5% around the doses chosen, the selected Gem standard doses were 1400 mg, 1600 mg, 1800 mg and 2000 mg. Following the DB scheme, the frequency of prescription of standard and individualised Gem doses was analysed over a period of 10 months. The four selected Gem standard doses were aseptically prepared in polyolefin infusion bags. Each series of 20 bags was stocked under refrigerated storage conditions (4°C) for up to 84 days. The quantification of Gem without dilution of the infusion bags was obtained by the development of a HPLC method coupled to a diode array detector (DAD) or an evaporative light scattering detector (ELSD).

RESULTS

During the 10-month period following implementation of the DB, 75.6% of the 1266 prescribed doses were covered by the four standardised preparations. The number of different Gem doses was reduced from 183 to 55. Concerning the Gem quantification, both heteroscedasticity and non-linearity were observed with DAD. Using an ELSD, the trueness values were between 98.59% and 101.52% with excellent repeatability values between 0.66% and 1.42%.

CONCLUSION

A new HPLC method has been developed for the quantification of Gem without dilution of the infusion bags prepared in advance as a result of a target DB scheme successfully implemented in our pharmacy department.

Safety, Immunogenicity, and 1-Year Efficacy of Universal Cancer Peptide-Based Vaccine in Patients With Refractory Advanced Non-Small-Cell Lung Cancer: A Phase Ib/Phase IIa De-Escalation Study

PURPOSE

Universal cancer peptide-based vaccine (UCPVax) is a therapeutic vaccine composed of two highly selected helper peptides to induce CD4+ T helper-1 response directed against telomerase. This phase Ib/IIa trial was designed to test the safety, immunogenicity, and efficacy of a three-dose schedule in patients with metastatic non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with refractory NSCLC were assigned to receive three vaccination doses of UCPVax (0.25 mg, 0.5 mg, and 1 mg) using a Bayesian-based phase Ib followed by phase IIa de-escalating design. The primary end points were dose-limiting toxicity and immune response after three first doses of vaccine. Secondary end points were overall survival (OS) and progression-free survival at 1 year.

RESULTS

A total of 59 patients received UCPVax; 95% had three prior lines of systemic therapy. No dose-limiting toxicity was observed in 15 patients treated in phase Ib. The maximum tolerated dose was 1 mg. Fifty-one patients were eligible for phase IIa. The third and sixth dose of UCPVax induced specific CD4+ T helper 1 response in 56% and 87.2% of patients, respectively, with no difference between three dose levels. Twenty-one (39%) patients achieved disease control (stable disease, n = 20; complete response, n = 1). The 1-year OS was 34.1% (95% CI, 23.1 to 50.4), and the median OS was 9.7 months, with no significant difference between dose levels. The 1-year progression-free survival and the median OS were 17.2% (95% CI, 7.8 to 38.3) and 11.6 months (95% CI, 9.7 to 16.7) in immune responders (P = .015) and 4.5% (95% CI, 0.7 to 30.8) and 5.6 months (95% CI, 2.5 to 10) in nonresponders (P = .005), respectively.

CONCLUSION

UCPVax was highly immunogenic and safe and provide interesting 1-year OS rate in heavily pretreated advanced NSCLC.

Compliance with Early Long-Term Prophylaxis Guidelines for Severe Hemophilia A

OBJECTIVES

To evaluate the applicability and compliance with guidelines for early initiation of long-term prophylaxis in infants with severe hemophilia A and to identify factors associated with guideline compliance.

STUDY DESIGN

This real-world, prospective, multicenter, population-based FranceCoag study included almost all French boys with severe hemophilia A, born between 2000 and 2009 (ie, after guideline implementation).

RESULTS

We included 333 boys in the study cohort. The cumulative incidence of long-term prophylaxis use was 61.2% at 3 years of age vs 9.5% in a historical cohort of 39 boys born in 1996 (ie, before guideline implementation). The guidelines were not applicable in 23.1% of patients due to an early intracranial bleeding or inhibitor development. Long-term prophylaxis was delayed in 10.8% of patients. In the multivariate analysis, 2 variables were significantly associated with "timely long-term prophylaxis" as compared with "delayed long-term prophylaxis": hemophilia treating center location in the southern regions of France (OR 23.6, 95% CI 1.9-286.7, P = .013 vs Paris area) and older age at long-term prophylaxis indication (OR 7.2 for each additional year, 95% CI 1.2-43.2, P = .031). Long-term prophylaxis anticipation was observed in 39.0% of patients. Earlier birth year (OR 0.5, 95% CI 0.3-0.8, P = .010 for birth years 2005-2009 vs 2000-2004) and age at first factor replacement (OR 1.9 for each additional year, 95% CI 1.2-3.0, P = .005) were significantly associated with "long-term prophylaxis guideline compliance" vs "long-term prophylaxis anticipation."

CONCLUSIONS

This study suggests that long-term prophylaxis guidelines are associated with increased long-term prophylaxis use. However, early initiation of long-term prophylaxis remains a challenge.

Use of Desirability Functions Associated with a Chemometric Method To Optimize Separation of a Compound Mixture by Liquid Chromatography

A chemometric method using a desirability function was used to optimize the liquid chromatographic separation of 10 benzodiazepines in a minimum analysis time. Most efficient separation was achieved with acetonitrile–water (60 + 40) at a flow rate of 1 mL/min and a column temperature of 47°C.

Differential role for CD277 as a co-regulator of the immune signal in T and NK cells

The human butyrophilin (BTN) 3 or CD277 molecules belong to the B7 family members and are expressed in various immune cells such as T and NK cells. Here, we show that CD277 triggering considerably enhances TCR-induced cytokine production and cell proliferation, even when another co-stimulatory molecule, CD28, is engaged. These CD277-induced additive functional effects are in accordance with the detection of early T-cell activation events such as TCR-induced cell signaling being increased upon CD277 engagement. However, we found that CD277 triggering is not involved in CD16- or NKp46-induced NK cell activation. BTN3/CD277 comprises three structurally related members, BTN3A1, BTN3A2 and BTN3A3. CD277 antibodies recognize all isoforms and we describe a differential expression of BTN3 isoforms between T and NK cells that could explain differential CD277 functions between T and NK cells. Our results show that, while T cells express all BTN3/CD277 transcripts, NK cells express mostly BTN3A2, which lacks the B30.2 intracellular domain. Furthermore, NKp30-induced cytokine production is decreased by the specific engagement of BTN3A2, but not by BTN3A1 triggering. Thus, we provide new insights into the CD277 co-stimulatory pathway that may differentially participate in the regulation of various cell-mediated immune responses.

Key role played by a butyrophilin family gene product in human gd T cell activation (66.39)

The major peripheral Vg9Vd2 T cell subset in humans is activated by small phosphorylated metabolites of the isoprenoid synthesis pathway (referred to as phosphoantigens (P-Ag)), which are overexpressed in tumor and infected cells. The molecular partners and the mechanisms involved in P-Ag-mediated activation of Vg9Vd2 T cells remain elusive. In line with the recently described implication of murine Skint-1, a butyrophilin (BTN) family-related molecule, in selection of murine gd T cells, we show that several mAbs against a human BTN-related product with yet unknown function, which is ubiquitously expressed at the surface of hemopoietic cells sensitize a broad array of target cells to specific Vg9Vd2 T cell recognition (cytolysis, cytokines release, proliferation). Although this process is Vg9Vd2 TCR-dependent and involves gamma/delta chain residues previously shown to be critical for P-Ag-induced activation, we failed to detect any significant modulation of MVA pathway genes expression, nor any increase of endogenous P-Ag (IPP/ApppI) accumulation within mAb-treated target cells. We also identified a BTN-specific mAb that specifically inhibited Vg9Vd2 T cell activation triggered by endogenous or exogenous P-Ag.Moreover BNT knockdown abrogated Vg9Vd2 responses to PAg. Taken together, our results support a unique and critical contribution of BTN-related products in the regulation of TCR-mediated activation of human Vg9Vd2 T cells.

B and T lymphocyte attenuator is highly expressed on CMV-specific T cells during infection and regulates their function

B and T lymphocyte attenuator (BTLA), like its relative programmed cell death-1 (PD-1), is a receptor that negatively regulates murine T cell activation. However, its expression and function on human T cells is currently unknown. We report in this study on the expression of BTLA in human T cell subsets as well as its regulation on virus-specific T cells during primary human CMV infection. BTLA is expressed on human CD4(+) T cells during different stages of differentiation, whereas on CD8(+) T cells, it is found on naive T cells and is progressively downregulated in memory and differentiated effector-type cells. During primary CMV infection, BTLA was highly induced on CMV-specific CD8(+) T cells immediately following their differentiation from naive cells. After control of CMV infection, BTLA expression went down on memory CD8(+) cells. Engagement of BTLA by mAbs blocked CD3/CD28-mediated T cell proliferation and Th1 and Th2 cytokine secretion. Finally, in vitro blockade of the BTLA pathway augmented, as efficient as anti-PD-1 mAbs, allogeneic as well as CMV-specific CD8(+) T cell proliferation. Thus, our results suggest that, like PD-1, BTLA provides a potential target for enhancing the functional capacity of CTLs in viral infections.

Cardiovascular effects of arginase inhibition in spontaneously hypertensive rats with fully developed hypertension

AIMS

Growing evidence suggests that arginase misregulation plays a key role in the pathophysiology of essential hypertension. In the present study, we investigated the potential cardiovascular therapeutic effects of a long-term treatment with an arginase inhibitor in adult spontaneously hypertensive rats (SHR) with fully developed hypertension.

METHODS AND RESULTS

Treatment of 25-week-old SHR with the arginase inhibitor N(omega)-hydroxy-nor-L-arginine (nor-NOHA, 40 mg/day for 10 weeks) sustainably reduced systolic blood pressure (-30 mmHg, P < 0.05). The antihypertensive effect of nor-NOHA was associated with changes on mesenteric artery reactivity including the restoration of angiotensin-II-induced contraction and acetylcholine-induced vasodilation to the values of normotensive Wistar Kyoto rats. Both nitric oxide synthase and cyclooxygenase-dependent mechanisms account for the improvement of endothelial function afforded by the arginase inhibitor, which in addition blunted hypertension-induced endothelial arginase I overexpression in mesenteric arteries. Nor-NOHA also prevented the remodelling of aorta as measured by collagen content and media/lumen ratio, and improved the compliance of carotid artery in SHR. Cardiac fibrosis assessed by collagen content of left heart ventricle was reduced by nor-NOHA, with no significant effect on cardiac hypertrophy.

CONCLUSION

Our results report that a long-term treatment with an arginase inhibitor reduced blood pressure, improved vascular function, and reduced cardiac fibrosis in SHR with fully developed hypertension. These data suggest that arginase represents a promising novel target for pharmacological intervention in essential hypertension.

Time course of vascular arginase expression and activity in spontaneously hypertensive rats

There is growing evidence that vascular arginase plays a role in pathophysiology of vascular diseases. We recently reported high arginase activity/expression in young adult hypertensive spontaneously hypertensive rats (SHR). The aim of the present study was to characterize the time course of arginase pathway abnormalities in SHR and to explore the contributing role of hemodynamics and inflammation. Experiments were conducted on 5, 10, 19 and 26-week-old SHR and their age-matched control Wistar Kyoto (WKY) rats. Arginase activity as well as expression of arginase I, arginase II, endothelial and inducible NOS were determined in aortic tissue extracts. Levels of L-arginine, NO catabolites and IL-6 (a marker of inflammation) were measured in plasma. Arginase activity/expression was also measured in 10-week-old SHR previously treated with hydralazine (20 mg/kg/day, per os, for 5 weeks). As compared to WKY, SHR exhibited high vascular arginase I and II expression from prehypertensive to established stages of hypertension. However, a mismatch between expression and activity was observed at the prehypertensive stage. Arginase expression was not related either to plasma IL-6 levels or to expression of NOS. Prevention of hypertension by hydralazine significantly blunted arginase upregulation and restored arginase activity. Importantly, arginase activity and blood pressure (BP) correlated in SHR. In conclusion, our results demonstrate that arginase upregulation precedes blood pressure rising and identify elevated blood pressure as a contributing factor of arginase dysregulation in genetic hypertension. They also demonstrated a close relationship between arginase activity and BP, thus making arginase a promising target for antihypertensive therapy.

Potentiation of the bactericidal activity of Harungana madagascariensis Lam. ex Poir. (Hypericaceae) leaf extract against oral bacteria using poly (D, L-lactide-co-glycolide) nanoparticles: in vitro study

Harungana madagascariensis Lam. ex Poir. (Hypericaceae) is known to have biological properties with mainly antibacterial, antifungal, and antiviral effects. The objective of this study was to investigate the in vitro bactericidal activity of the ethyl acetate H. madagascariensis leaf extract (HLE) on the main oral bacterial strains largely implicated in dental caries and gingivitis infections, and the possibility of potentialization of HLE antibacterial effects using the poly (D,L-lactide-co-glycolide) nanoparticles (PLG-NP). The microdilution technique and the interfacial polymer deposition following the solvent diffusion method were used to investigate the in vitro bactericidal activity of ethyl acetate HLE and to prepare nanoparticles, respectively. HLE showed significant bactericidal effects against the bacterial strains tested, with minimal bactericidal concentration (MBC) to 5 x 10(2) mg/l or less, except for Lactobacillus casei with 7.5 x 10(2) mg/l. With the HLE incorporated into PLG nanoparticles (HLE-PLG-NP), we observed diminution of the bactericidal concentration compared to HLE, the upper MBC being of 1.875 x 10(2) mg/l. Incorporation of the HLE into a colloidal carrier optimized its antibacterial performance.

Chromatographic determination of the association constant between 8-methoxypsoralen and modified β-cyclodextrin: protective effect of hydroxypropyl-β-cyclodextrin on 8-methoxypsoralen toxicity in human keratinocytes

The retention of 8-methoxypsoralen (8-MOP) on an immobilised hydroxypropyl-beta-cyclodextrin (HP-beta-CD) column was analysed in HPLC by the determination of its Langmuir distribution isotherm. A such method was used to confirm the potential drug complexing role of this cyclodextrin. The 8-MOP/HP-beta-CD association constant (K) was equal to 29.5 and 18.7 M-1, respectively, at a temperature equal to 5 and 25 degrees C, respectively. These association constant values were used to determine the cytotoxicity profile of human keratinocyte cell line (HaCaT) in relation to the complex concentration. It was showed through these data that HP-beta-CD had a cytoprotective since a reverse effect of HP-beta-CD on 8-MOP cytotoxicity was observed.

High-performance thin-layer chromatographic determination of 5-methoxypsoralen in serum from patients

A simple and rapid high-performance thin-layer chromatographic (HPTLC) determination of 5-methoxypsoralen in serum is necessary for the therapeutic survey of patients treated with Puvatherapy (psoralen+UVA). The assay for this biological fluid involves an extraction with heptane-dichloromethane (4:1, v/v). The analytical method is linear from 50 to 250 ng/ml. This assay range is adequate for analysing human serum, as it corresponds to psoralen concentrations measured in serum from patients treated with psoralen and UVA against psoriasis and vitiligo. The limit of detection is 15 ng/ml. The coefficient of variation was less than 7%.

Comparison of quantitative high performance thin layer chromatography and the high performance liquid chromatography of parabens

A method is described for the densitometric determination of the p-hydroxybenzoic esters and p-hydroxybenzoic acid in mixtures or in drugs. This method is compared with the one used in high performance liquid chromatography (HPLC). The calibration curves were linear in interval 0.250-3.60 mumol ml-1 per 200 nl per spot. The limit of detection and the relative standard deviation (RSD) are higher than in HPLC (RSD is 6% in HPTLC. 3% in HPLC; limit of detection about 40 pmol in HPTLC and 25 pmol in HPLC) but HPTLC quantitative determination of parabens in drugs is faster.

High-performance liquid chromatographic determination of tazobactam by precolumn derivatization

A new reversed-phase high-performance liquid chromatography (RP-HPLC) method for the detection and quantification of tazobactam in serum and haemofiltration fluid is described. The assay for these biological fluids involves an extraction with diethyl ether followed by derivatization using 1,2,4-triazole. The mobile phase consisted of phosphate buffer-methanol and the detection wavelength was 325 nm. The limit of detection was 0.05 microgram/ml in the two fluids and the calibration curves were linear over the range 0.1-50 micrograms/ml. For a tazobactam concentration equal to 1, 5 or 20 micrograms ml-1, the coefficients of variation were less than 5%. The assay was successfully applied to the analysis of samples from drug monitoring in a patient with renal insufficiency undergoing continuous venovenous haemofiltration (CVVH).

Rapid determination of sulbactam and tazobactam in human serum by high-performance liquid chromatography

A simple and rapid HPLC method for the determination of tazobactam and sulbactam, two beta-lactamase inhibitors, in serum for the therapeutic follow-up of patients is described. The effect of the pH of the aqueous mobile phase and column temperature on column efficiency and retention were examined and equations for their dependences were derived. The use of a chromatographic response function showed that methanol-buffer (5:95, v/v) (pH 6.3) as the mobile phase and a 45 degrees C column temperature were optimum values for chromatographic separation. The analytical method was linear from 10 to 200 micrograms/ml. This assay limit range is sufficient for the analysis of human serum. The limit of detection was 10 micrograms/ml for sulbactam and 5 micrograms/ml for tazobactam. The coefficient of variation was less than 5%. The speed at which this assay can be performed makes it especially useful for estimating the levels of these drugs in human serum.