CE-MS method development for peptides analysis, especially hepcidin, an iron metabolism marker.

in Electrophoresis (2009), 30(15), 2624-31

A method for the resolution of a peptides mixture including hepcidin-25, an iron metabolism marker, was developed by CE-ESI-MS. Several strategies were tested to optimize peptide separation, such as the ... [more ▼]

A method for the resolution of a peptides mixture including hepcidin-25, an iron metabolism marker, was developed by CE-ESI-MS. Several strategies were tested to optimize peptide separation, such as the addition of cyclodextrins or organic solvents in the BGE or the use of coated capillaries. Best results in terms of resolution, symmetry and efficiency were obtained with a BGE made of 500 mM ammonium acetate pH 4.5/ACN 70:30 v/v. Using the methodology of experimental design, BGE concentration, sheath liquid composition and MS-coupling parameters were then optimized in order to obtain the best signal intensity for hepcidin. Finally, a 225 mM BGE and a sheath liquid composed of isopropanol/water 80:20 v/v containing 0.5% v/v formic acid were selected as it constitutes the best compromise for selectivity, peak shape and sensitivity. [less ▲]

Evaluation of decision methodologies for analytical method validation

Poster (2009)

Analysis of several analytical method validation strategies

Poster (2009)

Methodologies for the transfer of analytical methods: A review.

in Journal of Chromatography. B : Analytical Technologies in the Biomedical & Life Sciences (2009), 877

The transfer of a method from a laboratory to a production site is an important step in the development cycle of new pharmaceutical products. Method transfers are increasingly implemented due to the ... [more ▼]

The transfer of a method from a laboratory to a production site is an important step in the development cycle of new pharmaceutical products. Method transfers are increasingly implemented due to the economical pressure coming from the rationalization of production sites, analytical subcontracting and fusion of pharmaceutical groups. However, no official guidance regarding study design, data analysis, or decision procedures is present neither in FDA documents nor in ICH documents for method transfers. The experiments performed in such a transfer and the methodology used to accept or reject it should be fitted for purpose. In order to provide to analysts a global view of the problematic of analytical method transfer, this paper reviews the documentation available in the scientific literature about the design of transfer studies and the required sample size. Special focus is also made on the statistical methodologies available for decision making with particular emphasis on risk management. Examples of transfer of pharmaceutical, bio-pharmaceutical and biological methods published in the literature are reviewed in order to illustrate the various possibilities among the strategies for methods transfer. [less ▲]

Rapport d'activités scientifiques du Projet ETI-QC N°716607

Report (2008)

Développement d'un logiciel basé sur l'intervalle de tolérance pour l'estimation de l'incertitude

Report (2008)

Chromatographic separation of a pharmaceutical formulation using Design of Experiment and Design Space.

Poster (2008, July)

Développement d'un logiciel basé sur l'intervalle de tolérance pour l'estimation de l'incertitude

Report (2008)

Liquid chromatographic determination of enrofloxacin in nasal secretions and plasma of healthy pigs using restricted access material for on-line sample clean-up

in Journal of Chromatography. A (2008), 1189(1-2), 456-466

A new fully automated method was developed for the quantitative analysis of an antibacterial drug, enrofloxacin (ENRO), in both nasal secretions and plasma samples of healthy pigs. The method is based on ... [more ▼]

A new fully automated method was developed for the quantitative analysis of an antibacterial drug, enrofloxacin (ENRO), in both nasal secretions and plasma samples of healthy pigs. The method is based on the use of a pre-column packed with restricted access material (RAM), namely RP-18 ADS (alkyl diol silica), for on-line sample clean-up coupled to a liquid chromatographic (LC) column containing octadecyl silica. The only off-line sample preparation was the 50-fold dilution of nasal secretions and plasma samples in the washing liquid composed of 25 mM phosphate buffer of pH 7.4. A 10 μl diluted sample volume was injected directly onto the pre-column and washed for 7 min. By rotation of a switching valve, the analyte of interest was eluted in the back-flush mode with the LC mobile phase which consisted in a mixture of 25 mM phosphate buffer of pH 3.0 and acetonitrile according to a segmented gradient elution. By a new rotation of the switching valve, the pre-column and the analytical column were equilibrated for 3 min with the initial mobile phases. The flow-rate was 0.8 ml min−1 for the washing liquid and 1.5 ml min−1 for the LC mobile phase. ENRO was detected by fluorescence at excitation and emission wavelengths of 278 and 445 nm, respectively. Finally, the developed method was validated using an original strategy based on total measurement error and accuracy profiles as a decision tool. The limits of quantitation of ENRO in plasma and in nasal secretions were 30.5 and 91.6 ng/ml, respectively. The validated method was then applied successfully to the determination of ENRO in healthy pigs treated by intramuscular injection at different doses (2.5, 10 and 30 mg/kg bodyweight) for a pilot study. This method could be also used for the simultaneous analysis of ENRO and its main metabolite, ciprofloxacin (CIPRO). [less ▲]

Risk-Based Approach for the Transfer of Quantitative Methods: Bioanalytical Applications

in Journal of Chromatography. A (2008), 1189

The transfer of analytical methods from a sending laboratory to a receiving one requires to guarantee that this last laboratory will obtain accurate results. Undeniably method transfer is the ultimate ... [more ▼]

The transfer of analytical methods from a sending laboratory to a receiving one requires to guarantee that this last laboratory will obtain accurate results. Undeniably method transfer is the ultimate step before routine implementation of the method at the receiving site. The conventional statistical approaches generally used in this domain which analyze separately the trueness and precision characteristics of the receiver do not achieve this. Therefore, this paper aims first at demonstrating the applicability of two recent statistical approaches using total error-based criterion and taking into account the uncertainty of the true value estimate of the sending laboratory, to the transfer of bioanalytical methods. To achieve this, they were successfully applied to the transfer of two fully automated liquid chromatographic method coupled on-line to solid-phase extraction. The first one was dedicated to the determination of three catecholamines in human urine using electrochemical detection, and the second one to the quantitation of N-methyl-laudanosine in plasma using fluorescence detection. Secondly, a risk-based evaluation is made in order to understand why classical statistical approaches are not sufficient to provide the guarantees that the analytical method will give most of the time accurate results during its routine use. Finally, some recommendations for the transfer studies are proposed. [less ▲]