Evaluation of a closed-system cytotoxic transfer device in a pharmaceutical isolator.

PURPOSE: The occupational risk associated with handling of cytotoxic anticancer drugs is well documented and, in many countries, pharmaceutical isolators are used to contain cytotoxic residues during preparation of cytotoxic infusions. Isolators are difficult to clean leading to concerns that cytotoxic contamination from the work area could be transferred to surfaces of products leaving the isolator. This study investigated the surface contamination arising from the preparation of five anticancer drug infusions (Epirubicin, Fluorouracil, Cisplatin, Oxaliplatin and Carboplatin) in a pharmaceutical isolator and compared use of a conventional syringe and needle technique with a closed-system drug transfer device (CSDTD). METHODS: Wipe samples were taken over 1 week from pre-defined areas in the isolator, gloves, preparation mats, and also from the surfaces of prepared cytotoxic infusion bags and pre-filled syringes to obtain baseline surface contamination data. Following operator familiarisation, the CSDTD was then introduced and sampling repeated for a further week (intervention period). The samples obtained were analysed using validated HPLC-UV, HPLC-FL and ICP-MS techniques, as appropriate. RESULTS: All surfaces sampled during baseline, including external surfaces of infusions and syringes, were contaminated with each marker drug. During the intervention phase, isolator surfaces were free from detectable contamination and the contamination measured on gloves, preparation mats and surface of infusions was markedly reduced. The frequency of contamination on syringe and infusion surfaces was also lower. CONCLUSION: Surface contamination from cytotoxic infusion preparation in a pharmaceutical isolator was significant and could transmit cytotoxic residues to patient and public areas via infusion surfaces. The frequency and amount of contamination were reduced by the CSDTD.

Guidelines for the practical stability studies of anticancer drugs: a European consensus conference.

Stability studies performed by the pharmaceutical industry are only designed to fulfill licensing requirements. Thus, post-dilution or -reconstitution stability data are frequently limited to 24h only for bacteriological reasons regardless of the true chemical stability which could, in many cases, be longer. In practice, the pharmacy-based centralized preparation may require infusions to be made several days in advance to provide, for example, the filling of ambulatory devices for continuous infusions or batch preparations for dose banding. Furthermore, a non-justified limited stability for expensive products is obviously very costly. Thus, there is a compelling need for additional stability data covering practical uses of anticancer drugs. A European conference consensus was held in France, May 2010, under the auspices of the French Society of Oncology Pharmacy (SFPO) to propose adapted rules on stability in practical situations and guidelines to perform corresponding stability studies. For each anticancer drug, considering their therapeutic index, the pharmacokinetics/pharmacodynamics (PK/PD) variability, specific clinical use and risks related to degradation products, the classical limit of 10% of degradation can be inappropriate. Therefore, acceptance limits must be clinically relevant and should be defined for each drug individually. Design of stability studies has to reflect the different needs of the clinical practice (preparation for the week-ends, outpatient transportations, implantable devices, dose banding…). It is essential to use validated stability-indicating methods, separating degradation products being formed in the practical use of the drug. Sequential temperature designs should be encouraged to replicate problems seen in daily practice such as rupture of the cold-chain or temperature-cycling between refrigerated storage and ambient in-use conditions. Stressed conditions are recommended to evaluate not only the role of classical variables (pH, temperature, light) but also the mechanical stress. Physical stability such as particles' formation should be systematically evaluated. The consensus conference focused on the need to perform more studies on the stability of biotherapies, including a minimum of three complementary separating methods and a careful evaluation of submicron aggregates. The determination of the biological activity of proteins could be also useful. A guideline on the practical stability of anticancer drugs is proposed to cover current clinical and pharmaceutical practice. It should contribute to improved security of use, optimization of centralized handling and reduced costs. Finally, we have attempted to establish a new drug stability paradigm based on practical clinical needs, to complement regulatory guidelines which are essentially orientated to the stability of manufactured drugs.

Dyspnoeic dysphasia: a series of unfortunate events.

We describe a case of a 56 year old man with no previous medical history who presented with sudden onset dyspnoea, expressive dysphasia, and right arm sensory loss and paresis. A diagnosis of bilateral pulmonary embolism and transient cerebral ischaemic attack was confirmed by CT pulmonary angiogram and MRI. Paradoxical embolism through an occult patent foramen ovale (PFO) was subsequently proven by contrast echocardiography. This case highlights a number of short and long-term management conundrums, that to date are incompletely addressed by clinical trials. These include timing of anticoagulation in patients with both venous thromboembolism and cerebral infarction, and the risk:benefit ratio of surgical closure of patent foramen ovale.

A national survey investigating UK prescribers' opinions on chemotherapy dosing and 'dose-banding'.

AIMS: The primary purpose of dose-banding for cancer chemotherapy is to reduce patient waiting times, but dose-banding also has additional benefits, such as reduced drug wastage, reduced stress for staff, and prospective quality control of infusions. However, the uptake of dose-banding seems fairly low. Possible reasons for this are a reluctance to use dose-banding for clinical reasons or a lack of awareness. Despite the seemingly minor change from established practice of dose preparation, dose-banding has the potential to alter patient chemotherapy exposure. The aim of this study was to investigate prescribers' awareness of dose-banding and their opinions on the scope and limitations of dose-banding in the context of UK chemotherapy services. MATERIALS AND METHODS: This survey was performed throughout the UK by use of a postal questionnaire, which was validated before national distribution to 1104 oncologists and haematologists. The questionnaire contained both quantitative and qualitative elements. A database was created for data entry and analysis. RESULTS: The response from prescribers was encouraging for a postal questionnaire, with a 35% response rate (387 responses). Many were aware of the concept of dose-banding (>80%) and were also supportive of the system. The weakness around body surface area-based dosing was a commonly discussed topic. However, opinions on which is the maximum acceptable deviation from the prescribed dose with dose-banding were controversial, and there was a concern about the lack of evidence to support the use of dose-banding. The views on whether carboplatin and targeted therapies should be dose-banded were also divided. CONCLUSIONS: There was general support for dose-banding, but concerns about the lack of an evidence base could be a barrier to the wider introduction of the system. Consequently, more clinical studies are required to justify the safety and efficacy of dose-banding, and also to evaluate whether dose-banding is acceptable within clinical trials.

Chemotherapy dosing part II: alternative approaches and future prospects.

This overview follows on from part I, which described the current practices used in chemotherapy dosing and the paucity of scientific evidence to support them. In part II, alternative approaches are discussed, both in terms of scientific rationale and practical application. These include therapeutic drug monitoring, the use of pharmacokinetic-pharmacodynamic relationships, flat-fixed dosing, Bayesian modelling and dose banding.

Chemotherapy dosing part I: scientific basis for current practice and use of body surface area.

Cytotoxic chemotherapy is characterised by a low therapeutic index and significant variability in therapeutic and toxic effects. In an attempt to reduce this variability, most chemotherapy doses are individualised according to patient body surface area (BSA). This practice, which was introduced almost 50 years ago, clearly has practical and economic implications for the healthcare system. Furthermore, the clinical value of this approach has, in recent years, been questioned. Despite established practice, chemotherapy dose selection remains complicated, partly because treatment effects are difficult to measure, partly because drugs are used in combination with other treatment modalities, and also because the patient's condition may change with disease progression. Various patient-related factors can affect drug pharmacokinetics (PK) and pharmacodynamics (PD), for example organ function, expression and activity of metabolising enzymes, drug resistance, body size, gender, age, concomitant disease and co-administration of other drugs. These factors may be of clinical significance in chemotherapy dose determination and measures of PK, PD or both feature in attempts to devise more rigorous methods for chemotherapy dosing. Part I of this series of two reviews describes the history and clinical impact of BSA-based chemotherapy, and examines the scientific evidence to support BSA dosing. It evaluates the factors affecting PK and PD for specific drugs that could inform and refine dose determination.

Improved LC assay for the determination of mitozantrone in plasma: analytical considerations.

Preliminary method development studies on mitozantrone (MTZ) revealed a number of characteristics which were found to be important in the analysis of patient samples for pharmacokinetic studies. MTZ rapidly bound to glass, particularly at low concentrations (< 10 ng ml-1), necessitating the use of silanized glassware or polypropylene tubes for the handling of all solutions containing MTZ. MTZ was also found to react with two commonly-used antioxidants; sodium metabisulphite and EDTA. However, solutions containing MTZ were found to be stabilized by the addition of ascorbic acid (0.5% w/v). In the absence of ascorbic acid, MTZ underwent rapid, biphasic degradation in plasma at 24 and 37 degrees C, with terminal half-lives of approximately 70 h. Ascorbic acid (0.5% 2/v) was found to stabilize plasma samples containing MTZ throughout work-up procedures and during frozen storage. The addition of ascorbic acid to the sample collection vial was also necessary to prevent MTZ degradation in the eluting solvent of the solid-phase extraction system. Another important consideration was the requirement for an equilibration period of > 5 min after the addition of ametantrone (AM) internal standard to plasma samples. This was essential, since the slope of the calibration plot obtained using non-equilibrated plasma was approximately 30% of that obtained for calibration plots using equilibrated plasma, and would result in erroneous determination of MTZ plasma concentrations. The fully developed assay was rapid, precise and sensitive (relative errors at 1 ng ml-1 = 2.3%). MTZ concentrations determined using the LC method described in this report correlated well with an independently developed ELISA technique (r = 0.995, n = 20).

Pulse shaping during Raman-seed amplification for short laser pulses.

Raman-seed pulse amplification in a one-dimensional backscattering geometry is investigated with the help of numerical simulations and analytical estimates. The significant dependence of the initial amplification on the pulse form is revisited on the basis of a three-wave interaction as well as a kinetic Vlasov model. It is shown how the short duration of the input seed pulse influences its subsequent behavior, depending on plasma density and pump strength. The evolution during a "start-up period," which has been observed earlier, can be explained analytically. In the nonlinear (pump depletion) regime, the pulse generated in the start-up period will be further amplified and may evolve into a self-similar π-pulse solution. The Vlasov code predicts algebraic growth in time of the seed amplitude, similar to the findings based on self-similar solutions of the three-wave-interaction model. An initially very narrow pulse is shown to grow more slowly than an initially broad one.

Practical guides. II: Hospital pharmacy quality control services.

This article briefly reviews the evolution, scope and operation of hospital quality control (QC) services. Recent initiatives and developments are considered alongside the traditional 'core' QC/quality assurance (QA) work. Important new areas of work which could benefit from QC involvement are also discussed.

The formulation and stability of a unit-dose oral vitamin K1 preparation.

A unit-dose oral vitamin K1 solution (1 mg ml-1) was developed for administration to neonates as prophylaxis against early haemorrhagic disease of the new-born. Previously, a multidose oral-drop solution was prepared from sterile ampoules of vitamin K1 injection (10 mg ml-1). The unit-dose preparation enabled accurate and convenient dose delivery and was more economical than the multidose solution. Furthermore, the preparation of sterile, single-dose units enabled the elimination of potentially harmful preservatives from the formulation. The unit-dose preparation was shown to be stable for 6 months under refrigerated storage conditions.

Stimulation of reductive dechlorination of tetrachloroethene in anaerobic aquifer microcosms by addition of short-chain organic acids or alcohols.

The effect of the addition of common fermentation products on the dehalogenation of tetrachloroethene was studied in methanogenic slurries made with aquifer solids. Lactate, propionate, crotonate, butyrate, and ethanol stimulated dehalogenation activity, while acetate, methanol, and isopropanol did not.

Novel liquid chromatographic assay for the low-level determination of apomorphine in plasma.

A novel HPLC assay which is rapid, reproducible and sensitive has been developed for the analysis of apomorphine in plasma. The assay incorporates boldine as an internal standard, and uses solid-phase extraction on C18 mini-columns for sample clean-up and concentration, so enabling quantitation of apomorphine at 500 pg/ml using fluorescence detection (lambda(ex) 270 nm, lambda(em) 450 nm). The HPLC assay comprised a 25 cm-long Techopak C18 column and a mobile phase of (0.25 M sodium dihydrogen phosphate plus 0.25% heptane sulphonic acid, to pH 3.3 with orthophosphoric acid) containing 30% (v/v) methanol and 0.003% (w/v) EDTA, run at a flow-rate of 1.5 ml/min. Calibration plots prepared in plasma were linear over the range 1-30 ng/ml, (limit of quantitation (LOQ) = 490 pg/ml) with R.S.D. of 0.05% and R.E. of 5.0% at the level of 1 ng/ml. Preliminary pharmacokinetic data from two patients given apomorphine by 12 h subcutaneous infusion (patient A dose = 35 mg and patient B dose = 141 mg) showed apomorphine elimination from plasma to fit a two-compartment model, with initial half-lives of 8.2 and 46.6 min, elimination half-lives of 76.4 and 166.5 min and area under the plasma concentration-time curve (AUC) values of 236 and 405 ng h/ml, respectively.