Development and application of a liquid chromatography coupled to mass spectrometry method for the simultaneous determination of 23 antineoplastic drugs at trace levels

The goal of this study was to develop a method for the simultaneous quantification of 23 commonly used antineoplastic drugs in a hospital pharmacy, using ultra-high pressure liquid chromatography separation coupled to tandem mass spectrometry detection (UHPLC-MS/MS). The following drugs were investigated: 5-fluorouracil, cytarabine, ganciclovir, gemcitabine, dacarbazine, methotrexate, pemetrexed, busulfan, topotecan, rentitrexed, ifosfamide, cyclophosphamide, etoposide, irinotecan, doxorubicin/epirubicin, vincristine, docetaxel, paclitaxel, daunorubicin, idarubicin, vinblastine, oxaliplatin and carboplatin. The chromatographic separation was performed on a phenyl-hexyl column (2.1 ×100 mm, 1.7 µm) with a gradient elution of methanol and water containing 10 mM ammonium formate adjusted to pH 4.9. All compounds were analyzed in less than 13 min and detected with a triple quadrupole mass spectrometer operating in MRM mode. Limits of detection (LODs) and limits of quantification (LOQs) were comprised between 0.01 and 5 ng.mL^-1, and between 0.5 and 5 ng.mL^-1, respectively. Accuracies ranged between 117% and 83% at the LOQ, intermediate and upper LOQ concentrations, with relative standard deviations (RSD) inferior to 8%, for all the antineoplastic drugs. Finally, the UHPLC-MS/MS method was successfully applied to the analysis of surface samples to evaluate the chemical contamination by these highly toxic compounds in a chemotherapy preparation unit in a hospital pharmacy with the purpose of monitoring the exposure of health care professionals.

Development and Proof of Concept of an Audit Toolkit for the Safe Handling of Cytotoxic Drugs in Low- and Middle-Income Countries

PURPOSE

Chemotherapies are considered high-risk drugs for patient and staff safety. Considering the rising burden of cancer and the increasing use of chemotherapy drugs in low- and middle-income countries (LMICs), promoting continuous improvements in the safety and quality of practices in these settings is essential. This paper describes the development and proof of concept of a toolkit to audit chemotherapy handling practices in the health care facilities of LMICs.

METHODS

A steering committee defined the audit method and the toolkit content. Several checklists were developed to facilitate the audit and data collection. Items included in checklists were derived from key reference works on safe handling. Different tools were validated using Delphi surveys and expert reviews. Audits of pilot sites were performed to test the toolkit's applicability and relevance.

RESULTS

The toolkit contains a 134-item global assessment tool for the different processes at each step of the medication pathway and three step-specific observation checklists to assess different health workers' practices during the prescription, preparation, and administration of chemotherapies. The toolkit also proposes using a surface-wipe sampling method to measure any cytotoxic contamination of the immediate environment. The toolkit was tested in three teaching hospitals in Africa.

CONCLUSION

The toolkit developed was successfully implemented in a variety of LMIC settings, providing a comprehensive evaluation of the quality and safety of the chemotherapy drug handling practices in participating health care facilities. This toolkit can help facilities in LMICs to implement a new approach to continuously improving the quality and safety of their practices and ultimately ensure patient and staff safety.

Chemical Decontamination of Hazardous Drugs: A Comparison of Solution Performances

OBJECTIVES

Over the past 40 years, numerous actions have been undertaken to decrease the contamination of hospital facilities by intravenous conventional antineoplastic drugs (ICADs) such as centralizing compounding in pharmacies, using personal protective equipment, specific compounding, or infusion devices. As recently proposed in the <USP800> monograph, an additional specific decontamination step must be envisaged. A recent literature review analysed and discussed the different solutions tested in terms of decontamination efficacy. This article aims to discuss the performance of these solutions in the framework of aseptic compounding.

METHODS

The same dataset used in the previous literature review was reanalysed according to other parameters so as to select decontamination solutions: overall decontamination efficiency (EffQ), tested contaminants, and the risks of use in daily practice.

RESULTS

Using an EffQ threshold of 90% resulted in discarding 26 out of the 59 solutions. Solutions were tested differently: 8 on 1 contaminant, 11 on 2 contaminants, and 14 solutions on between 3 and 11 contaminants. Three risks were identified to help make choices in routine practice: the mutagenicity of degradation products, the safety of operators and facilities, and respect for the aseptic environment.

CONCLUSIONS

From the results, performance is discussed according to specific situations: a one-time incident or the basic chemical contamination due to daily practice. Accordingly, the decontamination solution selected then required a risk analysis and an evaluation before implementing it in the daily practice of a compounding unit.

Efficiency of four solutions in removing 23 conventional antineoplastic drugs from contaminated surfaces

BACKGROUND

Residual contamination by intravenous conventional antineoplastic drugs (ICAD) is still a daily issue in hospital facilities. This study aimed to compare the efficiency (EffQ) of 4 different solutions to remove 23 widely used ICADs from surfaces.

METHOD AND FINDINGS

A solution containing 23 ICADs (4 alkylating agents, 8 antimetabolites, 2 topo-I inhibitors, 6 topo-II inhibitors and 3 spindle poisons) was spread over 100 cm2 stainless steel. After drying, decontamination was carried out using 10×10 cm wipes moistened with 300 μL of one of the following solutions: 70% isopropanol (S1); ethanol-hydrogen peroxide 91.6-50.0 mg/g (S2); 10-2 M sodium dodecyl sulphate/isopropanol 80/20 (S3) or 0.5% sodium hypochlorite (S4). Six tests were performed for each decontamination solution. Two modalities were tested: a single wipe motion from top to bottom or vigorous wiping (n = 6 for each modality). Residual contamination was measured with a validated liquid chromatography with tandem mass spectrometry detection method. Solution efficiency (in %) was computed as follows: EffQ = 1-(quantity after decontamination/quantity before decontamination), as median (min-max) for the 23 ICADs. The overall decontamination efficiency (EffQ) of the 4 solutions was compared by a Kruskall-Wallis test. Decontamination modalities were compared for each solution and per ICAD with a Mann-Whitney test (p<0.05). EffQ were significantly different from one solution to the next for single wipe motion decontamination: 79.9% (69.3-100), 86.5% (13.0-100), 85.4% (56.5-100) and 100% (52.9-100) for S1, S2, S3 and S4 (p<0.0001), respectively. Differences were also significant for vigorous decontamination: EffQ of 84.3% (66.0-100), 92.3% (68.7-100), 99.6% (84.8-100) and 100% (82.9-100) for S1, S2, S3 and S4, respectively (p<0.0001). Generally, vigorous decontamination increased EffQ for all tested solutions and more significantly for the surfactant.

CONCLUSION

Decontamination efficiency depended on the solution used but also on the application modality. An SDS admixture seems to be a good alternative to sodium hypochlorite, notably after vigorous chemical decontamination with no hazard either to materials or workers.

Anticorps monoclonaux biosimilaires

La mise sur le marché de biosimilaires requiert une démonstration stricte de la similarité avec l’anticorps de référence, au travers d’études précliniques et cliniques. Cet article synthétise l’ensemble des analyses physicochimiques et fonctionnelles mises en œuvre in vitro, préalables à la réalisation d’études cliniques. Pour chaque caractéristique critique de l’anticorps, nous avons détaillé les techniques analytiques communément employées, leur principe de fonctionnement, ainsi que le type d’informations que ces techniques permettent d’obtenir.

Validation and uncertainty estimation for trace amounts determination of 25 drugs used in hospital chemotherapy compounding units

The validation and uncertainty assessment of the analytical method developed for the simultaneous determination of 25 anticancer drugs commonly handled in hospital pharmacy was reported. Selected compounds were 5-fluorouracil, cytarabine, fludarabine phosphate, ganciclovir, gemcitabine, dacarbazine, methotrexate, pemetrexed, busulfan, raltitrexed, etoposide phosphate, topotecan, ifosfamide, cyclophosphamide, irinotecan, doxorubicin, epirubicin, daunorubicin, idarubicin, vincristine, vinblastine, vinorelbine, docetaxel and paclitaxel. Accuracy and uncertainty profiles were obtained for all compounds. Quantitative performances were satisfactory in term of specificity, sensitivity, precision and accuracy. Repeatability (1.9-25.4%) and intermediate precision (2.7-29%) were determined for all target compounds. Lower limits of quantification between 1 and 25 ng/mL were obtained. Uncertainty associated to measurement of routine samples was evaluated. The multi-targeted method was specific and reliable and was successfully applied to wipe samples from hospital pharmacy chemotherapy compounding unit and to the determination of outside contamination of vials from pharmaceutical manufacturers.

Efficiency of degradation or desorption methods in antineoplastic drug decontamination: A critical review

Although considerable efforts have been made over the last 40 years, occupational exposure to antineoplastic drugs is still a daily concern, since eradicating such contamination from workplaces seems unattainable. Considerable data are currently available on the risks associated with their use at work. Hospital facilities are often cleaned with marketed antimicrobials whose chemical decontamination efficacy certainly differs but remains unknown. To keep compounding facilities sterile, alcohol-based solutions are frequently used but with very limited efficiency. It would be particularly useful if a decontamination method could be added to the means already available so that all conventional antineoplastic drug contamination could be removed. Several degradation methods or desorption methods have previously been experimented, with varying success. They have never been compared or discussed in terms either of efficiency or usability. This review aims to analyse and discuss the results of each degradation or decontamination procedure and to compare them. This should facilitate selection of the method to be implemented in daily practice.

A decontamination process adding a tensioactive agent and isopropanol to a closed-system drug transfer device for better control of isolator contamination. A prospective, parallel study

Background

Despite the use of closed system drug transfer devices (CSTD), residual contamination from antineoplastic drugs is still detected inside isolators. The aim of this study was to compare the decontamination level obtained using a CSTD + standard cleaning procedure with a CSTD + standard cleaning procedure + specific decontamination procedure.

Methods and findings

A comparative and prospective study was carried out in a newly opened compounding unit. Compounding was performed with a CSTD (BD-Phaseal, Becton-Dickinson). In the Control isolator (C), the cleaning process was completed daily with a standard biocide solution (Anioxyspray^TM, Anios, France). In the Intervention isolator (I), weekly decontamination with a homemade admixture of sodium dodecyl sulfate 10⁻² M/70% isopropanol (80/20, v/v) was added. Monitoring was performed via a validated LC-MS/MS method. Eight drugs (cyclophosphamide, cytarabine, dacarbazine, fluorouracile, gemcitabine, ifosfamide, irinotecan and methotrexate) were monitored daily over 14 consecutive weeks on three sites inside the isolators: gloves, workbench and window. Results are presented as the odds-ratio (OR) of contamination and as overall decontamination efficiency (Eff_Q, %). The proportion of Eff_Q ≥ 90% was assessed by a Fisher’s exact test (p<0.05). Overall contamination rates (CR, %) were significantly different from one isolator to the other (CR_C = 25.3% vs. CR_I = 10.4%; OR = 0.341; p<0.0001). Overall Eff_Q values (median; 1^st and 3^rd quartiles) were higher in the intervention isolator (I: 78.3% [34.6%;92.6%] vs. C: 59.5% [-5.5%;72.6%]; p = 0.0015) as well as the proportion of days with an Eff_Q ≥ 90% (I: 42.9% vs. C: 7.1%; p = 0.077) but very variable depending on drugs.

Conclusion

Adding a decontamination protocol with a tensioactive agent to a CSTD leads to better control of chemical contamination inside isolators. Improving decontamination by increasing decontamination frequency or modifying the protocol will be further studied.

Current possibilities of liquid chromatography for the characterization of antibody-drug conjugates

Antibody Drug Conjugates (ADCs) are innovative biopharmaceuticals gaining increasing attention over the last two decades. The concept of ADCs lead to new therapy approaches in numerous oncological indications as well in infectious diseases. Currently, around 60 CECs are in clinical trials indicating the expanding importance of this class of protein therapeutics. ADCs show unprecedented intrinsic heterogeneity and address new quality attributes which have to be assessed. Liquid chromatography is one of the most frequently used analytical method for the characterization of ADCs. This review summarizes recent results in the chromatographic characterization of ADCs and supposed to provide a general overview on the possibilities and limitations of current approaches for the evaluation of drug load distribution, determination of average drug to antibody ratio (DAR_av), and for the analysis of process/storage related impurities. Hydrophobic interaction chromatography (HIC), reversed phase liquid chromatography (RPLC), size exclusion chromatography (SEC) and multidimensional separations are discussed focusing on the analysis of marketed ADCs. Fundamentals and aspects of method development are illustrated with applications for each technique. Future perspectives in hydrophilic interaction chromatography (HILIC), HIC, SEC and ion exchange chromatography (IEX) are also discussed.

Antineoplastic drugs and their analysis: a state of the art review

We provide an overview of the analytical methods available for the quantification of antineoplastic drugs in pharmaceutical formulations, biological and environmental samples.

Long-term stability of ganciclovir in polypropylene containers at room temperature

Purpose Ganciclovir is increasingly provided by hospital pharmacy production unit in a ready-to-use form, in order to improve the safety of healthcare workers and the efficiency of the organisation. The objective of this study was to develop a stability-indicating method to assay ganciclovir and determine the stability of ganciclovir in syringes (5 mg/mL) and infusion bags (0.25 and 5 mg/mL) at two different temperatures. Method Ganciclovir solutions (0.25 mg/mL and 5 mg/mL) in 0.9% sodium chloride were prepared in 50 mL polypropylene syringes or 100 mL polypropylene infusion bags and stored at 2-8℃ and 23-27℃. The chemical stability was measured using a stability-indicating Ultra High Performance Liquid Chromatography coupled to mass spectrometry method. Physical stability was assessed by visual inspection. Results No significant loss of ganciclovir under any of the tested conditions was observed in this study. All solutions remained clear through the study period. Conclusion All tested formulations remained stable for at least 185 days independently of container type, temperature or concentration studied.

Reliability of chemotherapy preparation processes: Evaluating independent double-checking and computer-assisted gravimetric control

Background and objectives Centralized chemotherapy preparation units have established systematic strategies to avoid errors. Our work aimed to evaluate the accuracy of manual preparations associated with different control methods. Method A simulation study in an operational setting used phenylephrine and lidocaine as markers. Each operator prepared syringes that were controlled using a different method during each of three sessions (no control, visual double-checking, and gravimetric control). Eight reconstitutions and dilutions were prepared in each session, with variable doses and volumes, using different concentrations of stock solutions. Results were analyzed according to qualitative (choice of stock solution) and quantitative criteria (accurate, <5% deviation from the target concentration; weakly accurate, 5%-10%; inaccurate, 10%-30%; wrong, >30% deviation). Results Eleven operators carried out 19 sessions. No final preparation (n = 438) contained a wrong drug. The protocol involving no control failed to detect 1 of 3 dose errors made and double-checking failed to detect 3 of 7 dose errors. The gravimetric control method detected all 5 out of 5 dose errors. The accuracy of the doses measured was equivalent across the control methods ( p = 0.63 Kruskal-Wallis). The final preparations ranged from 58% to 60% accurate, 25% to 27% weakly accurate, 14% to 17% inaccurate and 0.9% wrong. A high variability was observed between operators. Discussion Gravimetric control was the only method able to detect all dose errors, but it did not improve dose accuracy. A dose accuracy with <5% deviation cannot always be guaranteed using manual production. Automation should be considered in the future.

Dynamics of active pharmaceutical ingredients loads in a Swiss university hospital wastewaters and prediction of the related environmental risk for the aquatic ecosystems

The wastewater contamination of a Swiss university hospital by active pharmaceutical ingredient (API) residues was evaluated with a three months monitoring campaign at the outlet of the main building. Flow-proportional samples were collected with an automatic refrigerated sampler and analyzed for 15 API, including antibiotics, analgesics, antiepileptic and anti-inflammatory drugs, by using a validated LC-MS/MS method. The metals Gd and Pt were also analyzed using ICP-MS. Measured concentrations were compared to the predicted ones calculated after the drug average consumption data obtained from the hospital pharmacy. The hospital contribution to the total urban load was calculated according to the consumption data obtained from city pharmacies. Lastly, the environmental hazard and risk quotients (RQ) related to the hospital fraction and the total urban consumption were calculated. Median concentrations of the 15 selected compounds were ranging from 0.04 to 675 μg/L, with a mean detection frequency of 84%. The ratio between predicted and measured environmental concentrations (PEC/MEC) has shown a good accuracy for 5 out of 15 compounds, revealing over- and under-estimations of the PEC model. Mean daily loads were ranging between 0.01 and 14.2g/d, with the exception of paracetamol (109.7 g/d). The hospital contribution to the total urban loads varied from 2.1 to 100% according to the compound. While taking into account dilution and removal efficiencies in wastewater treatment plant, only the hospital fraction of the antibiotics ciprofloxacin and sulfamethoxazole showed, respectively, a high (RQ>1) and moderate (RQ>0.1) risk for the aquatic ecosystems. Nevertheless, when considering the total urban consumption, 7 compounds showed potential deleterious effects on aquatic organisms (RQ>1): gabapentin, sulfamethoxazole, ciprofloxacin, piperacillin, ibuprofen, diclofenac and mefenamic acid. In order to reduce inputs of API residues originating from hospitals various solutions can be envisioned. With results of the present study, hospital managers can start handling this important issue.

Prioritization methodology for the monitoring of active pharmaceutical ingredients in hospital effluents

The important number of active pharmaceutical ingredients (API) available on the market along with their potential adverse effects in the aquatic ecosystems, lead to the development of prioritization methods, which allow choosing priority molecules to monitor based on a set of selected criteria. Due to the large volumes of API used in hospitals, an increasing attention has been recently paid to their effluents as a source of environmental pollution. Based on the consumption data of a Swiss university hospital, about hundred of API has been prioritized following an OPBT approach (Occurrence, Persistence, Bioaccumulation and Toxicity). In addition, an Environmental Risk Assessment (ERA) allowed prioritizing API based on predicted concentrations and environmental toxicity data found in the literature for 71 compounds. Both prioritization approaches were compared. OPBT prioritization results highlight the high concern of some non steroidal anti-inflammatory drugs and antiviral drugs, whereas antibiotics are revealed by ERA as potentially problematic to the aquatic ecosystems. Nevertheless, according to the predicted risk quotient, only the hospital fraction of ciprofloxacin represents a risk to the aquatic organisms. Some compounds were highlighted as high-priority with both methods: ibuprofen, trimethoprim, sulfamethoxazole, ritonavir, gabapentin, amoxicillin, ciprofloxacin, raltegravir, propofol, etc. Analyzing consumption data and building prioritization lists helped choosing about 15 API to be monitored in hospital wastewaters. The API ranking approach adopted in this study can be easily transposed to any other hospitals, which have the will to look at the contamination of their effluents.

Efficacy of Two Cleaning Solutions for the Decontamination of 10 Antineoplastic Agents in the Biosafety Cabinets of a Hospital Pharmacy

OBJECTIVE

This study aimed to evaluate two cleaning solutions for the chemical decontamination of antineoplastic agents on the surfaces of two biosafety cabinets routinely used for chemotherapy preparation in a hospital pharmacy.

METHODS

For almost 1 year (49 weeks), two different solutions were used for the weekly cleaning of two biosafety cabinets in a hospital pharmacy's centralized cytotoxic preparation unit. The solutions evaluated were a commercial solution of isopropyl alcohol (IPA) and water (70:30, vol:vol), and a detergent solution constituted by 10(-2)M of sodium dodecyl sulfate (SDS) with 20% IPA. Seven areas in each biosafety cabinet were wiped 14 times throughout the year, before and after the weekly cleaning process, according to a validated procedure. Samples were analyzed using a validated method of high-performance liquid chromatography coupled to mass spectrometry. The decontamination efficacy of these two solutions was tested for 10 antineoplastic agents: cytarabine, gemcitabine, methotrexate, etoposide phosphate, irinotecan, cyclophosphamide, ifosfamide, doxorubicin, epirubicin, and vincristine.

RESULTS

Overall decontamination efficacies observed were 82±6% and 49±11% for SDS solution and IPA, respectively. Higher contamination levels were distributed on areas frequently touched by the pharmacy technicians-such as sleeves and airlock handles-than on scale plates, gravimetric control hardware, and work benches. Detected contaminations of cyclophosphamide, ifosfamide, gemcitabine, and cytarabine were higher than those of the others agents. SDS solution was almost 20% more efficient than IPA on eight of the antineoplastic agents.

CONCLUSION

Both cleaning solutions were able to reduce contamination levels in the biosafety cabinets. The efficacy of the solution containing an anionic detergent agent (SDS) was shown to be generally higher than that of IPA and, after the SDS cleaning procedure, biosafety cabinets demonstrated acceptable contamination levels.

Determination of the external contamination and cross-contamination by cytotoxic drugs on the surfaces of vials available on the Swiss market

INTRODUCTION

The external contamination and cross-contamination by cytotoxic drugs on the surface (outside and septum) of 133 vials from various manufacturers and available on the Swiss market were evaluated. All of the tested vials contained one of the following active ingredients: cyclophosphamide, cytarabine, doxorubicin, epirubicin, etoposide phosphate, gemcitabine, ifosfamide, irinotecan, methotrexate or vincristine.

METHODS AND MATERIALS

The validated wiping liquid chromatography-mass spectrometry method used in this study allowed for the simultaneous determination of these 10 cytotoxic drugs in less than 30 min.

RESULTS

External contamination by cytotoxic drugs was detected on 63% of tested vials (outside and septum). The highest contamination level was observed on etoposide phosphate vials with 1896.66 ng of active ingredient on the outside of the vial. Approximately 20% of the contaminated vials had greater than 10 ng of cytotoxic drugs. Chemical contamination on the septum was detected on 38% of the vials. No contamination or very low levels of cytotoxic drugs, less than 1 ng per vial, were detected on the vials protected by plastic shrink-wrap. Traces of cytotoxic drugs different from the active ingredient were detected on 35% of the tested vials.

CONCLUSION

Handling cytotoxic vials with gloves and having a procedure for the decontamination of vials are of the utmost importance for reducing exposure to cytotoxic drugs. Moreover, manufacturers must improve their procedures to provide products free from any contamination.

Evaluation of decontamination efficacy of cleaning solutions on stainless steel and glass surfaces contaminated by 10 antineoplastic agents

OBJECTIVES

The handling of antineoplastic agents results in chronic surface contamination that must be minimized and eliminated. This study was designed to assess the potential of several chemical solutions to decontaminate two types of work surfaces that were intentionally contaminated with antineoplastic drugs.

METHODS

A range of solutions with variable physicochemical properties such as their hydrophilic/hydrophobic balance, oxidizing power, desorption, and solubilization were tested: ultrapure water, isopropyl alcohol, acetone, sodium hypochlorite, and surfactants such as dishwashing liquid (DWL), sodium dodecyl sulfate (SDS), Tween 40, and Span 80. These solutions were tested on 10 antineoplastic drugs: cytarabine, gemcitabine, methotrexate, etoposide phosphate, irinotecan, cyclophosphamide, ifosfamide, doxorubicin, epirubicin, and vincristine. To simulate contaminated surfaces, these molecules (200ng) were deliberately spread onto two types of work surfaces: stainless steel and glass. Recovered by wiping with a specific aqueous solvent (acetonitrile/HCOOH; 20/0.1%) and an absorbent wipe (Whatman 903®), the residual contamination was quantified using high-performance liquid chromatography (HPLC) coupled to mass spectrometry. To compare all tested cleaning solutions, a performance value of effectiveness was determined from contamination residues of the 10 drugs.

RESULTS

Sodium hypochlorite showed the highest overall effectiveness with 98% contamination removed. Ultrapure water, isopropyl alcohol/water, and acetone were less effective with effectiveness values of 76.8, 80.7, and 40.4%, respectively. Ultrapure water was effective on most hydrophilic molecules (97.1% for cytarabine), while on the other hand, isopropyl alcohol/water (70/30, vol/vol) was effective on the least hydrophilic ones (85.2% for doxorubicin and 87.8% for epirubicin). Acetone had little effect, whatever the type of molecule. Among products containing surfactants, DWL was found effective (91.5%), but its formulation was unknown. Formulations with single surfactant non-ionics (tween 40 and span 80) or anionic (SDS) were also tested. Finally, solutions containing 10(-2) M anionic surfactants and 20% isopropyl alcohol had the highest global effectiveness at around 90%. More precisely, their efficacy was the highest (94.8%) for the most hydrophilic compounds such as cytarabine and around 80.0% for anthracyclines. Finally, the addition of isopropyl alcohol to surfactant solutions enhanced their decontamination efficiency on the least hydrophilic molecules. Measured values from the stainless steel surface were similar to those from the glass one.

CONCLUSION

This study demonstrates that all decontamination agents reduce antineoplastic contamination on work surfaces, but none removes it totally. Although very effective, sodium hypochlorite cannot be used routinely on stainless steel surfaces. Solutions containing anionic surfactant such as SDS, with a high efficiency/safety ratio, proved most promising in terms of surface decontamination.

Validation and long-term evaluation of a modified on-line chiral analytical method for therapeutic drug monitoring of (R,S)-methadone in clinical samples

Matrix effects, which represent an important issue in liquid chromatography coupled to mass spectrometry or tandem mass spectrometry detection, should be closely assessed during method development. In the case of quantitative analysis, the use of stable isotope-labelled internal standard with physico-chemical properties and ionization behaviour similar to the analyte is recommended. In this paper, an example of the choice of a co-eluting deuterated internal standard to compensate for short-term and long-term matrix effect in the case of chiral (R,S)-methadone plasma quantification is reported. The method was fully validated over a concentration range of 5-800 ng/mL for each methadone enantiomer with satisfactory relative bias (-1.0 to 1.0%), repeatability (0.9-4.9%) and intermediate precision (1.4-12.0%). From the results obtained during validation, a control chart process during 52 series of routine analysis was established using both intermediate precision standard deviation and FDA acceptance criteria. The results of routine quality control samples were generally included in the +/-15% variability around the target value and mainly in the two standard deviation interval illustrating the long-term stability of the method. The intermediate precision variability estimated in method validation was found to be coherent with the routine use of the method. During this period, 257 trough concentration and 54 peak concentration plasma samples of patients undergoing (R,S)-methadone treatment were successfully analysed for routine therapeutic drug monitoring.

Analytical discrimination of poisonous and nonpoisonous chemotypes of giant fennel (Ferula communis L.) through their biologically active and volatile fractions

Giant fennel (Ferula communis L.) from Sardinia is characterized by two chemotypes with different biological activities. One chemotype is poisonous, due to prenylcoumarins, and responsible for ferulosis, which mainly affects sheep and goats, cattle, and horses; the other chemotype is nonpoisonous and contains daucane esters. The two chemotypes cannot be distinguished botanically. High-performance liquid chromatography-diode array-ultraviolet detection-mass spectrometry (HPLC-DAD-UV-MS) analysis of the composition of the fractions containing the biologically active metabolites and of the volatile fractions, by gas chromatography-mass spectrometry (GC-MS), of both essential oil and headspace sampled by headspace solid-phase microextraction (HS-SPME) are here shown to be effective in discriminating the poisonous and nonpoisonous chemotypes. HS-SPME with CAR/PDMS/DVB in combination with GC-MS has also been found to be a successful, fully automated one-step method for rapid and unequivocal discrimination of the two chemotypes, using aristolene and allohedycaryol as markers of the poisonous and nonpoisonous chemotypes, respectively.