References of "Netchacovitch, Lauranne"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailA new criterion to assess distributional homogeneity in hyperspectral images of solid pharmaceutical dosage forms
Sacre, Pierre-Yves ULiege; Lebrun, Pierre ULiege; Chavez, Pierre-François ULiege et al

in Analytica Chimica Acta (2014), 818

During galenic formulation development, homogeneity of distribution is a critical parameter to check since it may influence activity and safety of the drug. Raman hyperspectral imaging is a technique of ... [more ▼]

During galenic formulation development, homogeneity of distribution is a critical parameter to check since it may influence activity and safety of the drug. Raman hyperspectral imaging is a technique of choice for assessing the distributional homogeneity of compounds of interest. Indeed, the combination of both spectroscopic and spatial information provides a detailed knowledge of chemical composition and component distribution. Actually, most authors assess homogeneity using parameters of the histogram of intensities (e.g. mean, skewness and kurtosis). However, this approach does not take into account spatial information and loses the main advantage of imaging. To overcome this limitation, we propose a new criterion: Distributional Homogeneity Index (DHI). DHI has been tested on simulated maps and formulation development samples. The distribution maps of the samples were obtained without validated calibration model since different formulations were under investigation. The results obtained showed a linear relationship between content uniformity values and DHI values of distribution maps. Therefore, DHI methodology appears to be a suitable tool for the analysis of homogeneity of distribution maps even without calibration during formulation development. [less ▲]

Detailed reference viewed: 106 (33 ULiège)
Full Text
Peer Reviewed
See detailDetermination of 4-aminophenol in a pharmaceutical formulation using Surface Enhanced Raman scattering: from development to method validation
De Bleye, Charlotte ULiege; Dumont, Elodie ULiege; Rozet, Eric ULiege et al

in Talanta (2013), 116

A Surface Enhanced Raman Scattering (SERS) method able to quantify 4-aminophenol in a pharmaceutical formulation based on acetaminophen, also called paracetamol, was developed and, for the first time ... [more ▼]

A Surface Enhanced Raman Scattering (SERS) method able to quantify 4-aminophenol in a pharmaceutical formulation based on acetaminophen, also called paracetamol, was developed and, for the first time, successfully validated. In this context, silver nanoparticles were synthesized according to the method described by Lee-Meisel and used as SERS substrate. The repeatability of the silver colloid synthesis was tested using different methods to characterise the size and the zeta potential of silver nanoparticles freshly synthesized. To optimize the SERS samples preparation, a design of experiments implicating concentrations of citrate-reduced silver nanoparticles and aggregating agent was performed in order to maximize the Raman signal enhancement. Finally, an approach based on tolerance intervals and accuracy profiles was applied in order to thoroughly validate the method in a range of concentrations comprised from 3 to 15 µg mL-1 using normalized band intensities. The standard addition method was selected as method calibration. Therefore, measurements were carried out on 4-aminophenol spiked solutions of the pharmaceutical formulation. Despite the well-known stability and reproducibility problems of SERS, the validation was performed using two operators and 5 batches of nanoparticles, one for each validation day. [less ▲]

Detailed reference viewed: 126 (66 ULiège)
Full Text
Peer Reviewed
See detailDevelopment of a quantitative approach based on surface-enhanced Raman chemical imaging (SER-CI)
De Bleye, Charlotte ULiege; Sacre, Pierre-Yves ULiege; Dumont, Elodie ULiege et al

Conference (2013, October 17)

During the last decade, Raman imaging has taken an important place in the pharmaceutical field [1-2]. It enables to acquire a visual representation of samples while quantifying and identifying molecules ... [more ▼]

During the last decade, Raman imaging has taken an important place in the pharmaceutical field [1-2]. It enables to acquire a visual representation of samples while quantifying and identifying molecules of these samples. However, this technique suffers from a lack of sensitivity and the appearance of fluorescence which can limit its pharmaceutical applications. One way to circumvent these limitations is Surface Enhanced Raman chemical imaging (SER-CI) which presents the advantages of Raman imaging and enables to dramatically increase the Raman scattering of molecules adsorbed or very close to metallic surfaces [3]. The number of publications regarding SER-CI in the pharmaceutical field is very limited probably due to the well-known stability and reproducibility problem of SERS and also due to the difficulty to obtain a homogeneous colloids covering of samples surface before SER-CI analyses. In this context, the possibility to develop a quantitative approach using SER-CI on a pharmaceutical model, presented as paracetamol tablet, was studied. The aim was to develop a SER-CI method enabling to quantify 4-aminophenol (4-AP), which is the main impurity of paracetamol actively research for its toxicity, at a concentration below its limit of specification of 1000 ppm [4]. This pharmaceutical model was first investigated using SERS and a quantitative method enabling to quantify 4-AP from 3 to 15 µg mL-1 was developed and validated [5]. Based on these previous results, the possibility to develop quantitative approach to quantify 4-aminophenol in paracetamol tablet using SER-CI was investigated. Different ways to cover the tablets surface by silver colloids were tested and a homogeneity study was performed in order to improve the repeatability of SER-CI analyses. Afterwards, the SER-CI approach was optimized and different spectral intensity normalizations were tested. Finally, a quantitative approach using SER-CI was developed enabling to quantify 4-AP from 0.025% to 0.2% (w/w) in paracetamol tablets. [less ▲]

Detailed reference viewed: 50 (9 ULiège)
See detailVibrational spectroscopy as PAT compliant tools
Ziemons, Eric ULiege; De Bleye, Charlotte ULiege; Chavez, Pierre-François ULiege et al

Scientific conference (2013, September 10)

In the last decades, intensive research and development dealing with NIR and Raman spectroscopy have taken place in industrial field, espacially in pharmaceutical industry. This enthusiasm can be ... [more ▼]

In the last decades, intensive research and development dealing with NIR and Raman spectroscopy have taken place in industrial field, espacially in pharmaceutical industry. This enthusiasm can be explained by the fact that this technique are regarded as promising and attractive tools in PAT, R&D and Green Chemistry frameworks. Their advantages such as non-invasive, non-destructive, fast data acquisition, minization of sample preparation step and the use of probes in on-line, in-line and at-line are expected to reach the aims of PAT, R&D and Green Chemistry. [less ▲]

Detailed reference viewed: 48 (21 ULiège)
Full Text
Peer Reviewed
See detailA new criterion to assess distributional homogeneity in hyperspectral images of solid pharmaceutical dosage forms
Sacre, Pierre-Yves ULiege; Lebrun, Pierre ULiege; Chavez, Pierre-François ULiege et al

Conference (2013, September)

During galenic formulation development, homogeneity of distribution is a critical parameter to check since it may influence activity and safety of the drug. Several techniques exist to assess this ... [more ▼]

During galenic formulation development, homogeneity of distribution is a critical parameter to check since it may influence activity and safety of the drug. Several techniques exist to assess this homogeneity, the most used and recognized being HPLC. However, these techniques are destructive, time consuming and uses a lot of organic solvents. Vibrational spectroscopies are promising green chemistry techniques that may replace HPLC for several analysis tasks thanks of their rapid, non-destructive and non-pollutant characteristics. Raman hyperspectral imaging is a technique of choice for assessing the distributional homogeneity of compounds of interest. Indeed, the combination of both spectroscopic and spatial information provides a detailed knowledge of chemical composition and component distribution. When dealing with hyperspectral imaging, multivariate data analysis is necessary to extract the concentration map of the compound of interest that will be used to assess sample homogeneity. Actually, most authors assess homogeneity using parameters of the histogram of intensities (e.g. mean, skewness and kurtosis). However, this approach does not take into account spatial information and loses the main advantage of imaging. Recently, Rosas et al. proposed a homogeneity index based on the Poole index. However, it necessitates cutting the maps in non-overlapping macropixels and is therefore quickly limited with small maps. To overcome this limitation, we propose a new criterion that combines Continuous Level Moving Blocks and homogeneity curves with a randomization step to assess the distributional homogeneity. This distributional homogeneity index (DHI) enables analysis of hyperspectral maps without apriori knowledge. It has been applied on five pharmaceutical formulations with different blending conditions. The uniformity content values of the API (present at a concentration of 7% w/w) measured by HPLC ranged from RSD: 0.46% to 11.04%. Ten tablets per formulation have been mapped over a region of interest of 4 mm². After extracting pure spectra by MCR-ALS, the concentration maps of the API were computed using classical least squares analysis. DHI have been computed with a hundred simulations for the randomization step for each concentration map. Afterwards, a mean DHI and standard deviation values were computed per formulation. A linear relationship has been observed between the RSD values and the mean DHI. These results enabled us to select the formulation with the best homogeneity. Further experiments are in progress to check whether hyperspectral imaging combined with DHI could be used in routine to assess blending homogeneity of well-known formulations. [less ▲]

Detailed reference viewed: 72 (25 ULiège)
Full Text
Peer Reviewed
See detailChemical imaging of small molecules from simple to complex matrices: Quantitative approaches based on Surface Enhanced Raman scattering
De Bleye, Charlotte ULiege; Sacre, Pierre-Yves ULiege; Chavez, Pierre-François ULiege et al

Conference (2013, July)

Surface Enhanced Raman scattering (SERS) allows to dramatically exalt the Raman diffusion of molecules absorbed or very closed to rough metallic surfaces while keeping their structural information. SERS ... [more ▼]

Surface Enhanced Raman scattering (SERS) allows to dramatically exalt the Raman diffusion of molecules absorbed or very closed to rough metallic surfaces while keeping their structural information. SERS chemical imaging, presenting a high specificity and sensibility, allows acquiring a visual representation of samples combining spectral and spatial measurements. This technique could become a powerful tool in pharmaceutical and biological analysis enabling to identify and quantify molecules thanks to chemometric evaluation while looking at their distribution or their interactions. In this context, SERS chemical imaging is investigated in detection or quantitative determination of molecules in pharmaceutical and biological matrices. The feasibility of making quantitative measurements using SERS is evaluated on small target molecules models such as 4-aminophenol and lactate. Firstly, a SERS method to quantify 4-aminophenol which is the primary impurity of acetaminophen coming from its degradation during the storage or from its synthesis was developed on a real pharmaceutical formulation. The standard addition method was selected as calibration method in order to take into account the matrix effect coming from the different components of the latter. Despite the well-known stability and repeatability problems of SERS, the method was thoroughly validated by means of accuracy profiles as decision tool. Moreover, this validation methodology allowed to define a first estimation of the real analytical performance of the technique. Secondly, the detection of lactate, which is a critical metabolite implicated in several metabolic disorders, was successfully tested in the physiological concentration in a simple matrix. Preliminary results for the determination of this metabolic biomarker were also very promising allowing to consider more complex matrices. Based on these results, SERS chemical imaging was implemented to detect 4-aminophenol in a pharmaceutical tablet formerly pulverised by a SERS substrate. Through this imaging technique, it was not only possible to detect the presence of the impurity at the limit of specification of 0.1% (w/w) but it was also possible to differentiate tablets comprising different concentrations of the latter. These promising results represent the first step towards quantitative measurements using SERS chemical imaging. [less ▲]

Detailed reference viewed: 151 (43 ULiège)