DEMARCHE STATISTIQUE DE LA VALIDATION ANALYTIQUE DANS LE DOMAINE PHARMACEUTIQUE (Méthodologie et exemple pratique)

Cet article a été élaboré dans le but d’aider les industriels du médicament, les organismes de contrôle nationaux à valider leurs procédures d’analyse. Le protocole expérimental appliqué dans ce document est basé sur une méthodologie commune inspirée de la stratégie des guidelines ICH (International Conference on Harmonization ) et celles de la SFSTP (Société Française des Sciences Techniques et Pharmaceutiques pour mieux encore optimiser le nombre d’essais à réaliser et satisfaire à l’étude des critères de validation.La démarche statistique qui sera appliquée aux données brutes est décrite. Et afin de mieux appréhender l’exploitation statistique des données brutes un exemple d’application est traité

Rapid extraction and detection of ellagic acid in plant samples using a selective magnetic molecularly imprinted polymer coupled to a fluorescence method

A remarkable growth was noticed in the development of molecularly imprinted polymers (MIPs), which have used as efficient synthetic antibodies that contain selective cavities to the target molecule. Hereunder, a novel strategy using MIP as a sorbent in solid-phase extraction was coupled to a fluorescence method for ellagic acid (EA) purification and immediate detection. The synthesis of magnetic-MIP (MMIP) using a rapid and green ultrasound technology was assessed by central composite design to determine the optimal polymerization conditions for a high-imprinting polymer. The MMIP was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning/transmission electron microscopy, which accurately confirmed the functional, magnetic, and morphological features of MMIP. The prepared MMIP was demonstrated to be selective for EA compared to many similar phenols. The spectrofluorometric method showed a linear range from 0.05 to 2 μg·mL−1 of EA, and the limits of detection (LOD) and quantification (LOQ) were 0.005 and 0.02 μg·mL−1, respectively. Besides, the novel proposed smartphone method using the ultraviolet lamp as the excitation source presented a linear range from 0.2 to 4 μg·mL−1, a LOQ of 0.2 μg·mL−1, and a LOD of 0.07 μg.mL−1. The proposed strategy revealed high efficiency in the extraction and detection of EA in grape, redberry, and green tea. Effectively, the calculated recoveries were ranging from 80 to 102% with low values of relative standard deviation ([removed]10 página

Valorisation du marc du café : extraction de l’huile et évaluation de son activité antioxydante

The spent coffee grounds are considered as a solid waste generated by coffee consumers. The present work aims to enhance this co-product rich in high value-added molecules. Indeed, the spent coffee grounds are extracted by two methods, Soxhlet and decoction. The solvent used in both processes to extract the lipid fraction was n-hexane. Both extractions, Soxhlet and decoction, were conducted under the same operating conditions. The Soxhlet extract 11% (dray mass) of oil after three hours of extraction and decoction extract 8% (dry mass) of oil after only 30 minutes. Preliminary characterization of these extracts, by the Folin Ciocalteu protocol, provided 28 mg GAE/g of total phenolic compounds for the Soxhlet extract, and 30 mg GAE/g for the decoction extract. The antioxidant activity of different extracts was assessed by two methods, the test of free radical scavenging, using the diphenyl picrylhydrazyl (DPPH•), and Ferric Reducing Antioxidant Power (FRAP) test. The extracts showed significant antioxidant potential. 70% of inhibition of DPPH° free radicals were observed for 30 min decoction extract and a higher iron reducing power for Soxhlet and decoction extracts.Le marc du café est considéré comme un déchet solide généré par les consommateurs de café moulu. Le présent travail a pour but de valoriser ce coproduit riche en molécules de haute valeur ajoutée. En effet, le marc du café est soumis à une extraction par deux procédés, le Soxhlet et la décoction. Le solvant utilisé dans les deux procédés pour extraire la fraction lipidique est le n-hexane. Les deux extractions, par Soxhlet et par décoction, ont été conduites dans les mêmes conditions opératoires. Le procédé Soxhlet abouti à 11% (base sèche) de l’huile totale de marc de café après trois heures d’extraction et environ 8% (base sèche) d’huile après seulement 30 minutes d’extraction par décoction. La caractérisation préliminaire de ces extraits a fourni, selon la méthode de Folin Ciocalteu, une teneur en composés phénoliques totaux de 28 mg GAE/g pour l’extrait de trois heures par Soxhlet, et 30 mg GAE/g pour l’extrait d’une heure par décoction. L’activité antioxydante des différents extraits a été évaluée par deux méthodes. Le test de piégeage du radical libre DiPhényl Picryl Hydrazyl (DPPH•) et le teste de réduction des ions de fer Ferric Reducing Antioxidant Power (FRAP). Les extraits ont manifesté un important potentiel antioxydant. Un pourcentage d’inhibition de 70% du radical DPPH remarqué pour l’extrait de 30 minutes par décoction et un pouvoir réducteur de fer plus élevé pour l’extrait de 4 heures par Soxhlet et celui de 3 heures par décoction

Surfactant modified carbon paste electrode: Part 2: Analytical performances

The hexadecylsulfonic acid (sodium salt) modified carbon paste electrode (HDSNa‐CPE) has been studied in batch and flowing systems, and its analytical performance has been established in comparison with a conventional carbon paste electrode (CPE). Amperometry, linear scan, and preconcentration voltammetry have been used for the investigation of several analytes of pharmacological interest. Because of the presence of surface functionalities, markedly different electrode responses have been observed at the HDSNa‐CPE depending on the nature (hydrophobicity and charge) of the investigated molecule. The HDSNa‐CPE showed, in linear scan voltammetry and for all the species investigated, higher responses compared to the CPE. The HDSNa‐CPE showed important current enhancements in voltammetric analysis of hydrophobic organic cations in acidic media and at low ionic strength. Copyright © 1994 VCH Publishers, Inc.SCOPUS: ar.jFLWNAinfo:eu-repo/semantics/publishe

Electrosynthese de poly(paraphenylene) en poudre et en films catalysee par des complexes du nickel

SIGLECNRS TD Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Electroanalysis of drugs at carbon paste electrodes modified by amphiphiles

info:eu-repo/semantics/nonPublishe

Application of Statistical Experimental Design and Surface Plot Technique to Optimize Oxygenated Apatite Synthesis

This work deals with oxygenated apatite synthesis from calcium chloride and phosphoric acid using a wet precipitation method. An experimental design is applied to precise the influence of the synthesis parameters (pH of the reaction medium, atomic ratio Ca/P of the reagents, concentration of the calcium solution (Ca2+), temperature of the reaction medium (T), and duration of the reaction (D)) on the chemical composition (Ca/P molar ratio, % O2, and % O22−). An empirical model was developed and validated by applying the ANOVA analysis incorporating the interaction effects of all parameters and optimized using the response surface methodology. A reproducible synthesis of more oxygenated apatite with speed of dissolution adaptable to that of the osseous neoformation and allowing a progressive diffusion of oxygenated species (Ca/P = 1.575) is attained