Extended physicochemical stability of cetuximab in opened vials and infusion bags when stored at 4°C and 25°C

INTRODUCTION

This study aimed to determine the stability of cetuximab: (1) under "in-use" conditions after dilution to 1 mg/mL in 0.9% sodium chloride in polyolefin bags and (2) as an undiluted solution (5 mg/mL) repackaged in polypropylene bags or kept in the vial after opening.

METHODS

Ready-to-use 500 mg/100 mL vials of cetuximab solution were diluted to 1 mg/mL in 100 mL bags of 0.9% sodium chloride or repackaged as a 5 mg/mL solution into empty 100 mL bags. Bags and vials were stored at 4°C for 90 days and 25°C for 3 days. A syringe sample of 7 mL was taken from each bag for the initial determinations. The sampled bags were weighed to determine their initial weight and placed under the planned storage conditions. The physicochemical stability of cetuximab was estimated using validated methods.

RESULTS

No changes in turbidity, no protein loss, and no changes in cetuximab tertiary structure were observed after 30 days of storage or when subjected to a temperature excursion of 3 days at 25°C and when stored at 4°C for up to 90 days, regardless of the concentrations and batches. The colligative parameters did not change under any of the tested conditions. No evidence of microbial growth was found in bags after 90 days of storage at 4°C.

CONCLUSION

These results support the extended in-use shelf-life of cetuximab vials and bags, which can be cost-effective for healthcare providers.

Biosimilarity. Do not confuse biosimilar and biocopy. Example of tenecteplase

Non-innovator biological products (NIBPs) or 'biocopies' are available in several countries at lower prices than biosimilars. These drugs, sometimes so-called 'biosimilars', may not meet all of the quality criteria expected of clinically equivalent products. NIBPs can exhibit major differences in physicochemical and pharmacological properties compared with their reference biological but may be presented to prescribers based on clinical trial data and claimed clinical equivalence. Tenecteplase (TNK-tpA) is a recombinant derivative of tissue plasminogen activator, used as a third-generation thrombolytic agent for treatment of acute myocardial infarction. A TNK-tPA presented as biosimilar to the originator (Metalyse®, Boehringer Ingelheim; TNKase®, Roche/Genentech) is now available for use in India (Elaxim®, Gennova Pharmaceuticals). Elaxim® is not approved in Europe or the USA but has been proposed in several countries as a replacement for the originator. Based on available literature, we discuss why this biocopy cannot be considered biosimilar to the originator tenecteplase. We describe clear differences in physicochemical and pharmacological properties. For example, the biocopy demonstrates clot lysis activity that is substantially lower than the originator and contains high concentrations of foreign proteins that confer potential for immunological reactions. Clinical data on the biocopy are limited; randomized trials to demonstrate the absence of difference in efficacy and safety between the biocopy and originator have not been conducted. This example demonstrates that confirmation of similarity, by close examination of pharmaceutical quality attributes, and preclinical and clinical data, is mandatory before presenting to prescribers a biological product as clinically equivalent.

Which treatment for the French revolutionist Jean-Paul Marat's dermatitis (1793)? A biomedical analysis of his bathtub deposits

The history of medicine makes it possible to understand both the evolution of the conceptualization of pathological processes, but also the modification of therapeutic principles and patient management. In the context of dermatology, we are interested here in the case of Jean-Paul Marat, who was murdered in his bathtub at the end of the 18th century in France and had severe dermatosis. Examination of deposits of pharmaceutical products inside the bathtub in which he spent most of his time made it possible to reconstruct the nosological and therapeutic framework of his dermatosis.

3D-Printed, Liquid-Filled Capsules of Concentrated and Stabilized Polyphenol Epigallocatechin Gallate, Developed in a Clinical Trial

In vitro studies have shown that epigallocatechin gallate (EGCG), the most potent antioxidant of the green tea polyphenol catechins, is able to effectively prevent the formation of amyloid plaques and induce their clearance. However, its high chemical reactivity promotes high chemical instability, which represents a major obstacle for the development of pharmaceutical forms containing solubilized EGCG, an essential condition for a better systemic passage via the oral route. After discovering that EGCG forms a deep eutectic with choline chloride, we exploited this property to formulate and patent liquid-filled capsules containing 200-800 mg of soluble EGCG in easy-to-administer sizes. The gelatin envelopes used are of the conventional type and their filling has been achieved using 3D printing technology. Not only did the EGCG-choline complex allow the formulation of hydrophilic solutions with a high concentration of active substance but it also contributed significantly to its chemical stability, since after at least 18 months of storage at 25 °C/60% RH and one year at 40 °C/75% RH, the capsules show unchanged hardness, chromatographic profiles and antioxidant activity compared to T0. Preclinical studies in monkeys showed that bioavailability was increased by a factor of 10 compared to marketed capsules comprising EGCG powder. This pharmaceutical development was conducted in the context of upcoming clinical trials to evaluate EGCG alone or in combination when treating transthyretin and light-chain cardiac amyloidosis.

Simple Approach to Enhance Green Tea Epigallocatechin Gallate Stability in Aqueous Solutions and Bioavailability: Experimental and Theoretical Characterizations

Because of its antioxidant, antimutagenic, and anti-infectious properties, epigallocatechin gallate (EGCG) is the most interesting compound among the green tea catechins polyphenols. However, its health effects are inconclusive due to its very low bioavailability, largely due to a particular instability that does not allow EGCG to reach the potency required for clinical developments. Over the last decade, many efforts have been made to improve the stability and bioavailability of EGCG using complex delivery systems such as nanotechnology, but these efforts have not been successful and easy to translate to industrial use. To meet the needs of a large-scale clinical trial requiring EGCG in a concentrated solution to anticipate swallowing impairments, we developed an EGCG-based aqueous solution in the simplest way while trying to circumvent EGCG instability. The solution was thoroughly characterized to sort out the unexpected stability outcome by combining experimental (HPLC-UV-mass spectrometry and infrared spectroscopy) and computational (density functional theory) studies. Against all odds, the EGCG–sucrose complex under certain conditions may have prevented EGCG from degradation in aqueous media. Indeed, in agreement with the ICH guidelines, the formulated solution was shown to be stable up to at least 24 months under 2–8 °C and at ambient temperature. Furthermore, considerable improvement in bioavailability in rats, against EGCG powder formulated in hard-gel capsules, was shown after gavage. Thus, the proposed formulation may provide an easily implementable platform to administer EGCG in the context of clinical development.

Investigation of the Physicochemical and Biological Stability of the Adalimumab Biosimilar CT-P17

INTRODUCTION

CT-P17 (Celltrion, Inc., Incheon, Republic of Korea) is a biosimilar of reference adalimumab (Humira^®; AbbVie Inc., North Chicago, IL, USA), which has recently received regulatory approval from the European Medicines Agency.

METHODS

This analysis was designed to evaluate the stability profile of CT-P17 compared with reference adalimumab and the currently licensed adalimumab biosimilars ABP 501 (Amjevita^®/Amgevita^®; Amgen Inc., Thousand Oaks, CA, USA) and SB5 (Imraldi^®; Biogen Inc., Cambridge, MA, USA) when stored at low temperature (5 °C) or room temperature (25 °C) with 60% relative humidity for up to 28 days.

RESULTS

Multiple orthogonal and complementary tests demonstrated that CT-P17 was stable for 28 days under all tested conditions, as well as for protein concentrations tested (50 vs 100 mg/mL), type of delivery device (autoinjector vs prefilled syringe), and manufacturing date (recently manufactured vs aged for 17 months). There were slight differences among products in terms of charge variants, oxidation level, purity, and number of subvisible particles; however, overall, the quality of each product was maintained over 28 days.

CONCLUSION

Our data suggest that CT-P17 may be used without any significant loss of stability when stored at 5 °C or 25 °C with 60% relative humidity for up to 28 days, and was not impacted by protein concentration tested and delivery device. Comparative stability data suggest that the appropriate maximum storage period for CT-P17 may be up to 28 days at room temperature with 60% relative humidity.

What is the role of technology in improving patient safety? A French, German and UK healthcare professional perspective

Patient safety in hospitals can be compromised by preventable adverse events (AE). Among the preventable AEs, hospital-acquired infections (HAIs) are one of the most burdensome, contributing to not only poorer patient outcomes but institutional burden through direct financial losses and increased patient length of stay.

 Technological innovations can enhance patient safety by automating tasks, introducing medication alerts, clinical reminders, improved diagnostic and consultation reports, facilitating information sharing, improving clinical decision-making, intercepting potential errors, reducing variation in practice, and managing workforce shortages as well as making complete patient data available.

 A multidisciplinary working group from three European countries was convened to discuss how to optimise the use of technology to reduce preventable AEs in acute care hospitals. The working group identified examples where they felt there were opportunities to streamline patient pathways, including antimicrobial stewardship, point of care testing, microbiology test reporting to streamline time from sample-taking to clinical decision and mobile automated dispensing systems, which can reduce the burden on overworked staff. The working group also discussed key factors that were critical to ensuring different stakeholders, both within and outside the hospital, could meaningfully contribute to improving patient safety. They agreed that technological approaches and advances would have limited impact without meaningful cultural changes at all levels of healthcare infrastructure to implement the benefits offered by current or future technologies.

Persistent swallowing disorders after extubation in mechanically ventilated patients in ICU: a two-center prospective study

Background

Persistent swallowing disorders (SD) are non-pulmonary complications of mechanical ventilation (MV). However, there are few clinical studies on persistent SD in critically ill patients undergoing tracheal intubation for MV. The aim of the present study was to assess the incidence and characteristics of clinical manifestations associated with persistent SD.

Methods

We prospectively evaluated in patients requiring more than 7 days of invasive MV the incidence and characteristics of clinical manifestations related to persistent SD. For this purpose, quality of swallowing was assessed within 24 h after extubation by an experienced physical therapist not directly involved in patient management. Swallowing assessment consisted in a specific standardized test combining a swallowing test and a full clinical evaluation of the cranial nerves involved in swallowing. In patients with SD on the first test, a second test was done within 48 h in order to discriminate between transient and persistent SD.

Results

Among the 482 patients mechanically ventilated more than 7 days, 138 were enrolled in this study. The first test performed 24 h after extubation revealed SD in 35 patients (25%). According to the second test performed 48 h later, SD were considered transient in 21 (15%) and persistent in 14 (10%) cases. Patients with persistent SD were older (66 ± 16 vs 58 ± 15 years), had lower bodyweight at admission (76 ± 15 vs 87 ± 23 kg) and received less often neuromuscular blocking agents (36% vs 66%) compared to patients without or with only transient SD. Patients with persistent SD had longer duration of Intensive Care Unit (ICU) stay after first extubation and longer delay to oral feeding than patients without or with only transient SD, respectively, 11 ± 9 vs 7 ± 6 days and 23 ± 33 vs 5 ± 7 days.

Conclusions

Based on a specific standardized clinical test, 25% of patients mechanically ventilated more than 7 days exhibited clinical manifestations of SD. However, SD were considered as persistent after extubation in only 10% of them. Persistent SD were associated with longer duration of ICU stay after extubation and longer time of enteral feeding.

Trial registration: The study is registered with Clinical Trials (NCT01360580).

Formulation and Administration of Biological Medicinal Products"

Monoclonal antibody (Mabs) containing medicinal products are widely used in clinical practice. Prior to parenteral administration, licensed Mab containing medicinal products are transferred to the ready-to-administer (RTA) forms. Reconstitution and/or preparation should follow the guidelines for Good Reconstitution/Good Preparation Practice. Preparation in the pharmacy must take place within the framework of a suitable quality management system. The responsible pharmacist must apply a risk assessment on the process to ensure the appropriate quality of the RTA preparation, especially because the extent of quality testing is limited by batch size (often one single unit) and time restraints. In these cases, appropriate quality is to be assured by means of qualification activities, environmental monitoring, process validation with growth medium and in-process controls. Correct labelling of the Mab containing RTA preparations includes a suitable storage advice and a defined shelf life. Physicochemical stability of a given Mab preparation can be assessed based on a specific stability study (supplied by the manufacturer in the SmPC or scientific journals, study published by an expert in a peer-reviewed scientific journal). Physicochemical stability studies require the use of various orthogonal physicochemical methods to detect accurately the degradation changes that may result from the deamidation, oxidation, disulfide formation, aggregation or fragmentation during storage. Complementary, biological activity can be measured. Compatibility studies of Mabs and devices used for preparation and administration are still scarce. Microbiological stability of Mab preparations is related to the complexity of the preparation process, the growth supporting nature of the preparation and the integrity of the container or container/closure combination. In use viability tests revealed that the potential of Mab preparations to support microbial growth was similar to that of the pure vehicle solutions used as control solutions. The enumerated microbial counts varied according to the species utilized and the type of Mab preparation. If sterility testing of the individual preparation is impossible, maximum permitted shelf life can be assessed empirically with regard to the maximum shelf lives defined in the USP <797> monograph. Finally, microbiological and physicochemical stability are to be considered concurrently when determining the shelf life of an individual Mab preparation. In each case, shelf life should be limited according to the shorter period of proven stability, either derived from the microbiological or physicochemical stability data.

Cancer, immune suppression and Coronavirus Disease-19 (COVID-19): Need to manage drug safety (French Society for Oncology Pharmacy [SFPO] guidelines)

The Coronavirus disease (COVID-19) pandemic is disrupting our health environment. As expected, studies highlighted the great susceptibility of cancer patients to COVID-19 and more severe complications, leading oncologists to deeply rethink patient cancer care. This review is dedicated to the optimization of care pathways and therapeutics in cancer patients during the pandemic and aims to discuss successive issues. First we focused on the international guidelines proposing adjustments and alternative options to cancer care in order to limit hospital admission and cytopenic treatment in cancer patients, most of whom are immunocompromised. In addition cancer patients are prone to polypharmacy, enhancing the risk of drug-related problems as adverse events and drug-drug interactions. Due to increased risk in case of COVID-19, we reported a comprehensive review of all the drug-related problems between COVID-19 and antineoplastics. Moreover, in the absence of approved drug against COVID-19, infected patients may be included in clinical trials evaluating new drugs with a lack of knowledge, particularly in cancer patients. Focusing on the several experimental drugs currently being evaluated, we set up an original data board helping oncologists and pharmacists to identify promptly drug-related problems between antineoplastics and experimental drugs. Finally additional and concrete recommendations are provided, supporting oncologists and pharmacists in their efforts to manage cancer patients and to optimize their treatments in this new era related to COVID-19.

[Interchangeability and substitution of biosimilars]

The rationality of the interchangeability of biosimilars is based on broad scientific evidence and numerous clinical experiences in real life which show no sign of reduced efficacy or different tolerance compared to the original molecule. The substitution of biosimilars (pharmaceutical act) remains widely contested in many countries, notably in France. However, it would make it possible to make very significant savings in a context of major acceleration in health spending. This reluctance is unfounded in light of the quality of biosimilars authorized in Europe and their rigorous evaluation. It is therefore essential to improve the information of health professionals and patients on these biosimilars.

In Vivo Comparative Study of Two Lactobionate Based Solutions for Prolonged Heart Preservation

The duration of safe heart preservation must be improved. Using a heterotopic heart transplantation model, we compared in vivo the recovery of rabbits hearts preserved with a K+ Lactobionate based fluid (UW: University of Wisconsin solution) or with a Na+Lactobionate based fluid. In the “preservation” group, hearts were cold stored (4°C) for 6 hours with UW (n=9) or Na+Lactobionate solution (n=9). In the “transplantation” group, cold storage was followed by 3 hours of reperfusion (UW: n=8, Na+Lactobionate solution: n=7). Functional recovery, adenine nucleotide pool, circulating blood cardiac enzymes, circulating blood and tissue malondialdehyde (MDA) were measured. Left ventricular enddiastolic and developed pressures at different preload levels were better after preservation with UW than with Na+Lactobionate solution (p<0.05). Also with UW, adenosine diphosphate and total adenine nucleotide content were significantly higher than with Na+Lactobionate solution (p<0.05) whereas adenosine triphosphate, monophosphate and energy charges were similar. Cardiac enzymes and tissue MDA were similar with UW and Na+Lactobionate solution. In circulating blood, MDA was not detected. These results enhance the superiority of UW solution over a Na+Lactobionate based solution for long term heart preservation.

Anti-colchicine Fab fragments prevent lethal colchicine toxicity in a porcine model: a pharmacokinetic and clinical study

Background: Colchicine poisoning is commonly lethal. Colchicine-specific Fab fragments increase rat urinary colchicine clearance and have been associated with a good outcome in one patient. We aimed to develop a porcine model of colchicine toxicity to study the pharmacokinetics and efficacy of ovine Fab.

Methods: A Göttingen minipig critical care model was established and serial blood samples taken for colchicine and Fab pharmacokinetics, clinical chemistry, and haematology. Animals were euthanised when the mean arterial pressure fell below 45 mmHg without response to vasopressor, or at study completion.

Results: Initial studies indicated that oral dosing produced variable pharmacokinetics and time-to-euthanasia. By contrast, intravenous infusion of 0.25 mg/kg colchicine over 1 h produced reproducible pharmacokinetics (AUC_0–20 343 [SD = 21] µg/L/h), acute multi-organ injury, and cardiotoxicity requiring euthanasia a mean of 22.5 (SD = 3.2) h after dosing. A full-neutralising equimolar Fab dose given 6 h after the infusion (50% first hour, 50% next 6 h [to reduce renal-loss of unbound Fab]) produced a 7.35-fold increase in plasma colchicine (AUC_0–20 2,522 [SD = 14] µg/L/h), and removed all free plasma colchicine, but did not prevent toxicity (euthanasia at 29.1 [SD = 3.4] h). Earlier administration over 1 h of the full-neutralising dose, 1 or 3 h after the colchicine, produced a 12.9-fold (AUC_0–20 4,433 [SD = 607] µg/L/h) and 6.0-fold (AUC_0–20 2,047 [SD = 51] µg/L/h) increase in plasma colchicine, respectively, absence of free plasma colchicine until 20 h, and survival to study end without marked cardiotoxicity.

Conclusions: Colchicine-specific Fab given early, in equimolar dose, bound colchicine, eliciting its movement into the blood, and preventing severe toxicity. Clinical studies are now needed to determine how soon this antidote must be given to work in human poisoning.

How to select a nanosimilar

Nanomedicines in the class of nonbiological complex drugs (NBCDs) are becoming increasingly available. Up to 23 nanomedicines have been approved, and approximately 50 are in clinical development. Meanwhile, the first nanosimilars have entered the market through the generic approval pathway, but clinical differences have been observed. Many healthcare professionals may be unaware of this issue and must be informed of these clinically relevant variances. This article provides a tool for rational decision making for the inclusion of nanomedicines into the hospital formulary, including defined criteria for evaluation of substitutability or interchangeability. The tool was generated by conducting a roundtable with an international panel of experts and follows the same thought process that was developed and published earlier for the selection of biologicals/biosimilars. In addition to the existing criteria for biosimilars, a set of seven criteria was identified that specifically apply to nanosimilars. These include (1) particle size and size distribution, (2) particle surface characteristics, (3) fraction of uncaptured bioactive moiety, (4) stability on storage, (5) bioactive moiety uptake and (6) distribution, and (7) stability for ready-to-use preparation. Pharmacists should utilize their pharmaceutical expertise to use the appropriate criteria to evaluate the comparability of the drug to decide on interchangeability or substitutability.

Identifying critical steps towards improved access to innovation in cancer care: a European CanCer Organisation position paper

In recent decades cancer care has seen improvements in the speed and accuracy of diagnostic procedures; the effectiveness of surgery, radiation therapy and medical treatments; the power of information technology; and the development of multidisciplinary, specialist-led approaches to care. Such innovations are essential if we are to continue improving the lives of cancer patients across Europe despite financial pressures on our healthcare systems. Investment in innovation must be balanced with the need to ensure the sustainability of healthcare budgets, and all health professionals have a responsibility to help achieve this balance. It requires scrutiny of the way care is delivered; we must be ready to discontinue practices or interventions that are inefficient, and prioritise innovations that may deliver the best outcomes possible for patients within the limits of available resources. Decisions on innovations should take into account their long-term impact on patient outcomes and costs, not just their immediate costs. Adopting a culture of innovation requires a multidisciplinary team approach, with the patient at the centre and an integral part of the team. It must take a whole-system and whole-patient perspective on cancer care and be guided by high-quality real-world data, including outcomes relevant to the patient and actual costs of care; this accurately reflects the impact of any innovation in clinical practice. The European CanCer Organisation is committed to working with its member societies, patient organisations and the cancer community at large to find sustainable ways to identify and integrate the most meaningful innovations into all aspects of cancer care.

_{36}^{96}Kr_{60}-Low-Z Boundary of the Island of Deformation at N=60

Prompt γ-ray spectroscopy of the neutron-rich ^{96}Kr, produced in transfer- and fusion-induced fission reactions, has been performed using the combination of the Advanced Gamma Tracking Array and the VAMOS++ spectrometer. A second excited state, assigned to J^{π}=4^{+}, is observed for the first time, and a previously reported level energy of the first 2^{+} excited state is confirmed. The measured energy ratio R_{4/2}=E(4^{+})/E(2^{+})=2.12(1) indicates that this nucleus does not show a well-developed collectivity contrary to that seen in heavier N=60 isotones. This new measurement highlights an abrupt transition of the degree of collectivity as a function of the proton number at Z=36, of similar amplitude to that observed at N=60 at higher Z values. A possible reason for this abrupt transition could be related to the insufficient proton excitations in the g_{9/2}, d_{5/2}, and s_{1/2} orbitals to generate strong quadrupole correlations or to the coexistence of competing different shapes. An unexpected continuous decrease of R_{4/2} as a function of the neutron number up to N=60 is also evidenced. This measurement establishes the Kr isotopic chain as the low-Z boundary of the island of deformation for N=60 isotones. A comparison with available theoretical predictions using different beyond mean-field approaches shows that these models fail to reproduce the abrupt transitions at N=60 and Z=36.

Implementation of automated dispensing cabinets for management of medical devices in an intensive care unit: organisational and financial impact

Background

Automated dispensing cabinets (ADCs) have been tested and approved for medication management in hospitals.

Objectives

First, to evaluate the logistics and organisational effect of a similar system for management of sterile medical devices in a medical intensive care unit (ICU). Second, to assess the cost savings of this new organisation for the sterile medical devices budget of this department.

Methods

The organisational effect was evaluated by comparing (1) the workload of head nurse, nursing auxiliary and pharmacy technician and (2) sterile medical devices emergency orders, 1 year before and after implementation of three ADCs and 100 wireless open-access devices. The hospital's costs (ADC, wireless devices and software) and benefits (stock value and resupplying value before and after implementation) were evaluated.

Results

Employment of ADCs led to organisational improvement: the total time saved by the pharmacy and ICU together was 34% of the time spent before introduction. The number of emergency orders decreased from 6% to 1% of total orders after 1 year. €55 000 were saved (stock value + resupplying value) 1 year after introduction of ADCs. These benefits were almost equal to the cost of introducing the system.

Conclusions

ADCs could provide an innovative and efficient solution for the management of sterile medical devices in hospitals. Further investigations are needed to complete the financial evaluation, and to develop this system to provide a secure a medical devices circuit.

[Study impacto: Descriptive analyzis of pharmacist's clinical practice in onco-hematology]

Pharmaceutical analyses of chemotherapy prescriptions by hospital pharmacists are activities codified by regulation and rules (bon usage). The involvement of the pharmacists in clinical pharmacy activities in the oncology setting is not clearly identified, justifying the development of a mapping of these activities from a questionnaire addressed to the professionals. One hundred and seven centers have participated to this study at the national level (overall participation rate of 32.4%). More than 95% of them used a computerized ordering system and three quarter of them submit the introduction of new compounds to an analysis by the drug therapeutic committee. Prescription analysis allowed detecting around 2% of errors from the current prescription. Clinical pharmacist participates to tumor boards of onco-hematology (RCP) at a level of 46% for senior pharmacist and 42% for junior pharmacist. This involvement in the RCP allowed anticipating protocol's modification and temporary used authorization. Ninety-two percent of the senior pharmacists estimate that they highlight the risk of no reimbursement for prescription out of the guideline during RCP, resulting to a modification of the prescription for 40% of them. This level of intervention is lower with respectively 64% and 10% for the juniors. This study underlines the expert value of the clinical pharmacist dedicated to oncology setting in pre and post analysis prescriptions. It could be targeted by a prospective analysis of both clinical and pharmacoeconomics impact of these interventions.

Review of therapeutic drug monitoring of anticancer drugs part 1--cytotoxics

Most anticancer drugs are characterised by a steep dose-response relationship and narrow therapeutic window. Inter-individual pharmacokinetic (PK) variability is often substantial. The most relevant PK parameter for cytotoxic drugs is the area under the plasma concentration versus time curve (AUC). Thus it is somewhat surprising that therapeutic drug monitoring (TDM) is still uncommon for the majority of agents. Goals of the review were to assess the rationale for more widely used TDM of cytotoxics in oncology. There are several reasons why TDM has never been fully implemented into daily oncology practice. These include difficulties in establishing appropriate concentration target ranges, common use of combination chemotherapies for many tumour types, analytical challenges with prodrugs, intracellular compounds, the paucity of published data from pharmacological trials and 'Day1 = Day21' administration schedules. There are some specific situations for which these limitations are overcome, including high dose methotrexate, 5-fluorouracil infusion, mitotane and some high dose chemotherapy regimens. TDM in paediatric oncology represents an important challenge. Established TDM approaches includes the widely used anticancer agents carboplatin, busulfan and methotrexate, with 13-cis-retinoic acid also recently of interest. Considerable effort should be made to better define concentration-effect relationships and to utilise tools such as population PK/PD models and comparative randomised trials of classic dosing versus pharmacokinetically guided adaptive dosing. There is an important heterogeneity among clinical practices and a strong need to promote TDM guidelines among the oncological community.

Therapeutic drug monitoring in cancer--are we missing a trick?

Therapeutic drug monitoring (TDM) can be defined as the measurement of drug in biological samples to individualise treatment by adapting drug dose to improve efficacy and/or reduce toxicity. The cytotoxic drugs are characterised by steep dose-response relationships and narrow therapeutic windows. Inter-individual pharmacokinetic (PK) variability is often substantial. There are, however, a multitude of reasons why TDM has never been fully implemented in daily oncology practice. These include difficulties in establishing appropriate concentration target, common use of combination chemotherapies and the paucity of published data from pharmacological trials. The situation is different with targeted therapies. The large interindividual PK variability is influenced by the pharmacogenetic background of the patient (e.g. cytochrome P450 and ABC transporters polymorphisms), patient characteristics such as adherence to treatment and environmental factors (drug-drug interactions). Retrospective studies have shown that targeted drug exposure correlates with treatment response in various cancers. Evidence for imatinib currently exists, others are emerging for compounds including nilotinib, dasatinib, erlotinib, sunitinib, sorafenib and mammalian target of rapamycin (mTOR) inhibitors. Applications for TDM during oral targeted therapies may best be reserved for particular situations including lack of therapeutic response, severe or unexpected toxicities, anticipated drug-drug interactions and concerns over adherence treatment. There are still few data with monoclonal antibodies (mAbs) in favour of TDM approaches, even if data showed encouraging results with rituximab and cetuximab. TDM of mAbs is not yet supported by scientific evidence. Considerable effort should be made for targeted therapies to better define concentration-effect relationships and to perform comparative randomised trials of classic dosing versus pharmacokinetically-guided adaptive dosing.

Characterization of mitotane (o,p'-DDD)--cyclodextrin inclusion complexes: phase-solubility method and NMR

Mitotane (o,p'-dichlorodimethyl dichloroethane [o,p'-DDD]) is used for the treatment of adrenocortical cancer and occasionally Cushing's syndrome. This drug is very poorly soluble in water, and following oral administration, approximately 60% of the dose is recovered in the feces unaltered. The preparation of a soluble formulation (i.e. by complexation with cyclodextrins) with improved bioavailability is the aim of this work. The inclusion of mitotane in methyl-ß-cyclodextrins was studied using both phase-solubility methods and NMR experiments. To elucidate the inclusion mechanism, o,p'-DDD was compared to its regioisomer (i.e. p,p'-DDD). It was demonstrated that two dimethyl-ß-cyclodextrins (DMßCD) can complex with the aromatic rings. From the phase-solubility diagrams, we observe that both cases are very different: K(1:1) is between 37 000 and 85 000 mol.l(-1), whereas K(1:2) is between 5.3 and 32 mol.l(-1). The NMR experiments confirmed the inclusion but it also gave an insight into the kinetics of the dissociation: the ortho-chloro moiety is in slow exchange on the NMR time scale, whereas the para-chloro moiety is in fast exchange rate.