Lionel Mercier

Identification and quantitation of antineoplastic compounds in chemotherapeutic infusion bags by use of HPTLC: application to the vinca-alkaloids.

An instrumental quantitative high-performance thin-layer chromatographic (HPTLC) method has been developed for the determination of vinca-alkaloids (antineoplastic compounds) in chemotherapeutic infusion bags prepared in a hospital pharmacy. The method uses automated band application onto silica gel plates containing a fluorescent indicator and scanning densitometry of fluorescence-quenched zones of samples and standards. Samples were analyzed to check the content of the active substance against the label declaration of the preparation. The four compounds were separated using the following solvent system CH(2)Cl(2)-CH(3)OH (93:7, v/v). Vincristine (VCR) and vinorelbine (NVB) were assessed in the same run whilst vinblastine (VLB) and vindesine (VDS) were analyzed in a second run. HPTLC allows the identification and the quantitation of more than 20 samples in the same chromatographic run. The analysis of the samples requires 30 min compared with more than 2 h using a typical HPLC method. Moreover, there is no need for a conditioning step, as with HPLC, and each analysis by HPTLC is less expensive.

Contribution of high-performance thin-layer chromatography to a pharmaceutical quality assurance programme in a hospital chemotherapy manufacturing unit

The Department of Clinical Pharmacy (DCP) in the Institut Gustave-Roussy (IGR) is equipped with a high-performance thin-layer chromatography (HPTLC) analytical platform. One of the numerous possible uses of HPTLC is post-production quality control of chemotherapy manufacturing. After 3 years of existence, routine validation of manufactured batches has attained considerable maturity: 24 cytotoxic agents can be controlled in terms of identity, purity and concentration. Approximately 50% of the sampled preparations are assessed. More than 97% were within specifications, 1.6% were not, probably due to incorrect homogenization before sampling; and 1% were not evaluable. Using HPTLC in a hospital manufacturing unit contributes to quality assurance programmes such as accreditation to which the IGR DCP is now committed but also ISO 9001:2000 certification concerning the chemotherapy manufacturing unit.

High-performance thin-layer chromatography with a derivatization procedure, a suitable method for the identification and the quantitation of busulfan in various pharmaceutical products

Busulfan is an alkylating agent widely used in combination chemotherapy regimens followed by allogeneic or autologous hematopoietic stem cell transplantation (HSCT). We present a rapid method for assaying busulfan in pharmaceutical preparations using high-performance thin-layer chromatography (HPTLC) and derivatization with 4-nitrobenzylpyridine. The method is accurate and precise and allows quantitation of busulfan in aqueous solutions from 100 to 500 microg/ml. It is suitable for identification. quantitation and stability studies of busulfan in pharmaceutical products, i.e. capsules or infusion bags prepared in a hospital pharmacy.

New Ifosfamide Analogs Designed for Lower Associated Neurotoxicity and Nephrotoxicity with Modified Alkylating Kinetics Leading to Enhanced in Vitro Anticancer Activity

Ifosfamide is a well known prodrug for cancer treatment with cytochrome P450 metabolism. It is associated with both antitumor activity and toxicities. Isophosphoramide mustard is the bisalkylating active metabolite, and acrolein is a urotoxic side product. Because acrolein toxicity is limited by coadministration of sodium mercaptoethanesulfonate, the incidence of urotoxicity has been lowered. Current evidence suggests that chloroacetaldehyde, a side-chain oxidation metabolite, is responsible for neurotoxicity and nephrotoxicity. The aim of our research is to prevent chloroacetaldehyde formation using new enantioselectively synthesized ifosfamide analogs, i.e., C7,C9-dimethyl-ifosfamide. We hypothesize that reduced toxicogenic catabolism may induce less toxicity without changing anticancer activity. Metabolite determinations of the dimethyl-ifosfamide analogs were performed using liquid chromatography and tandem mass spectrometry after in vitro biotransformation by drug-induced rat liver microsomes and human microsomes expressing the main CYP3A4 and minor CYP2B6 enzymes. Both human and rat microsomes incubations produced the same N-deschloroalkylated and 4-hydroxylated metabolites. A coculture assay of 9L rat glioblastoma cells and rat microsomes was performed to evaluate their cytotoxicity. Finally, a mechanistic study using 31P NMR kinetics allowed estimating the alkylating activity of the modified mustards. The results showed that C7,C9-dimethyl-ifosfamide exhibited increased activities, although they were still metabolized through the same N-deschloroalkylation pathway. Analogs were 4 to 6 times more cytotoxic than ifosfamide on 9L cells, and the generated dimethylated mustards were 28 times faster alkylating agents than ifosfamide mustards. Among these new ifosfamide analogs, the 7S,9R-enantiomer will be assessed for further in vivo investigations for its anticancer activity and its toxicological profile.

Microbiological and Physicochemical Stability of Oxycodone Hydrochloride Solutions for Patient-Controlled Delivery Systems

CONTEXT The use of patient-controlled analgesia (PCA) allows patients to be managed at home and may increase the quality of life of patients with regard to drug administration. To ensure that intact drug is delivered to the patient in this setting, it is important to study its microbiological and physicochemical stability. Although these factors have been widely studied for many parenteral opioids, very few authors have investigated oxycodone stability associated with long-duration infusion in cancer patients. OBJECTIVES The aim of this study was to assess the microbiological and physicochemical stability of oxycodone hydrochloride solution in PCA devices and thereby to determine the feasibility of extending the expiration dates after mixing. METHODS Sixteen CADD reservoirs and 32 Rythmic reservoirs were filled aseptically with pure (10 mg/mL) and diluted (1 mg/mL) oxycodone solution. Three different vehicles (0.9% sodium chloride, water for injection, and 5% dextrose) were used for dilution. Among the PCA systems stored over 28 days at room temperature, 16 Rythmic reservoirs were protected from light. Microbiological stability was assessed by performing sterility tests. The physicochemical study was performed by determining aspect, pH, osmolality evolution, and weight. Drug concentrations were determined using the stability-indicating high performance liquid chromatography combined to ultraviolet detection technique. RESULTS There was no significant change in pH, weight, and osmolality values of any solutions. No precipitation or change in color was observed in any of the sample solutions. There was no significant loss of oxycodone, and no trace of degradation products was detected. CONCLUSION This study indicates that pure and diluted oxycodone solutions in the PCA systems are stable for 28 days at room temperature when prepared aseptically.

Iron Overload Exacerbates Busulfan-Melphalan Toxicity Through a Pharmacodynamic Interaction in Mice

PurposeBusulfan-melphalan high-dose chemotherapy followed by autologous stem cell transplantation is an essential consolidation treatment of high-risk neuroblastoma in children. Main treatment limitation is hepatic veno-occlusive disease, the most severe and frequent extra-hematological toxicity. This life threatening toxicity has been related to a drug interaction between busulfan and melphalan which might be increased by prior disturbance of iron homeostasis, i.e. an increased plasma ferritin level.MethodsWe performed an experimental study of busulfan and melphalan pharmacodynamic and pharmacokinetics in iron overloaded mice.ResultsIron excess dramatically increased the toxicity of melphalan or busulfan melphalan combination in mice but it did not modify the clearance of either busulfan or melphalan. We show that prior busulfan treatment impairs the clearance of melphalan. This clearance alteration was exacerbated in iron overloaded mice demonstrating a pharmacokinetic interaction. Additionally, iron overload increased melphalan toxicity without altering its pharmacokinetics, suggesting a pharmacodynamic interaction between iron and melphalan. Based on iron homeostasis disturbance, we postulated that prior induction of ferritin, through Nrf2 activation after oxidative stress, may be associated with the alteration of melphalan metabolism.ConclusionIron overload increases melphalan and busulfan-melphalan toxicity through a pharmacodynamic interaction and reveals a pharmacokinetic drug interaction between busulfan and melphalan.

Dyslipidemia causes overestimation of plasma mitotane measurements

Summary Mitotane (o,p′-DDD) is the standard treatment for advanced adrenocortical carcinoma (ACC). Monitoring of plasma mitotane levels is recommended to look for a therapeutic window between 14 and 20mg/L, but its positive predictive value requires optimization. We report the case of an ACC patient with a history of dyslipidemia treated with mitotane in whom several plasma mitotane levels >30mg/L were found together with an excellent neurological tolerance. This observation led us to compare theoretical or measured o,p′-DDD and o,p′-DDE levels in a series of normolipidemic and dyslipidemic plasma samples to explore potential analytical issues responsible for an overestimation of plasma mitotane levels. We demonstrate an overestimation of mitotane measurements in dyslipidemic patients. Mitotane and o,p′-DDE measurements showed a mean 20% overestimation in hypercholesterolemic and hypertriglyceridemic plasma, compared with normolipidemic plasma. The internal standard p,p′-DDE measurements showed a parallel decrease in hypercholesterolemic and hypertriglyceridemic plasma, suggesting a matrix effect. Finally, diluting plasma samples and/or using phospholipid removal cartridges allowed correcting such interference. Learning points Hypercholesterolemia (HCH) and hypertriglyceridemia (HTG) induce an overestimation of plasma mitotane measurements. We propose a routine monitoring of lipidemic status. We propose optimized methodology of measurement before interpreting high plasma mitotane levels.