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See detailAN INNOVATIVE APPROACH TO SELECT THE PREDICTION MODEL IN THE DEVELOPMENT OF NIR SPECTROSCOPIC METHODS
Ziemons, Eric ULg; Mantanus, Jérôme ULg; Rozet, Eric ULg et al

Poster (2012, March)

Taking into account its non-invasive, non-destructive character and fast data acquisition, near infrared spectroscopy is more and more integrated in production processes to acquire analytical results ... [more ▼]

Taking into account its non-invasive, non-destructive character and fast data acquisition, near infrared spectroscopy is more and more integrated in production processes to acquire analytical results. Implementation of a NIR quantitative method is performed using an iterative heuristic approach that will ultimately build a model allowing the prediction of the concentration of the analyte of interest. In this context, the aim of the present study was to develop an innovative approach based on statistical tolerance intervals and the desirability index FMI (Fitting Model Index) to select the most appropriate prediction model from a list of candidate models instead of using conventional criteria such as R², RMSEC, RMSECV and RMSEP [1-2] without objective decision rules. This new approach is illustrated on different steps of a real pharmaceutical manufacturing process: water and Active Pharmaceutical Ingredient (API) determinations in pharmaceutical pellets. Variability sources such as production campaigns, batches, days and operators were introduced in the calibration and validation sets. Partial Least Square (PLS) regression on the calibration sets was performed to build prediction models of which the ability to quantify accurately was tested with the validation sets. Regarding the product specifications, the acceptance limits were set at 20% and 5%, for the moisture and API determination, respectively.As can be seen from Figure 1 and 2, this innovative approach based on the desirability index FMI of the accuracy profile enabled to build and select the most appropriate prediction model in full accordance with its very final goal, to quantify as accurately as possible the analytes of interest. [1] Hubert Ph. et al., J. Pharm. Biomed. Anal., 36, 2007, 579-586. [2] Rozet E. et al., Ana. Chim. Acta, 591, 2007, 239-247. [less ▲]

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See detailComments on “Uncertainty profiles for the validation of analytical methods” by Saffaj and Ihssane
Rozet, Eric ULg; Ziemons, Eric ULg; Marini Djang'Eing'A, Roland ULg et al

in Talanta (2012), 88

Saffaj et al., recently proposed an uncertainty profile for evaluating the validity of analytical methods using the statistical methodology of γ-confidence β-content tolerance intervals. This profile ... [more ▼]

Saffaj et al., recently proposed an uncertainty profile for evaluating the validity of analytical methods using the statistical methodology of γ-confidence β-content tolerance intervals. This profile assesses the validity of the method by comparing the method measurement uncertainty to a pre defined acceptance limit stating the maximum uncertainty suitable for the method under study. Several years earlier as stated by these authors a SFSTP (Société Française des Sciences et Techniques Pharmaceutique) commission has developed a similar profile called accuracy profile used to assess the validity of analytical methods. This accuracy profile also uses the methodology of statistical tolerance intervals, but β-expectation tolerance intervals. The uncertainty profile of Saffaj et al. and the accuracy profile of the SFSTP commission are both fulfilling the same final purpose. The core question is finally what statistical tolerance interval to use ? The aim of this letter to the editor is to discuss this question and provide arguments that β-expectation tolerance intervals should be prefered to assess the validity of the method as this type of interval give the guarantee that each future results has high probability to fall within pre-specified acceptance limits. [less ▲]

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See detailReply to the responses on the comments on “Uncertainty profiles for the validation of analytical methods” by Saffaj and Ihssane
Rozet, Eric ULg; Ziemons, Eric ULg; Marini Djang'Eing'A, Roland ULg et al

in Talanta (2012), 100

Saffaj et al., recently proposed an uncertainty profile for evaluating the validity of analytical methods using the statistical methodology of γ-confidence β-content tolerance intervals. This profile ... [more ▼]

Saffaj et al., recently proposed an uncertainty profile for evaluating the validity of analytical methods using the statistical methodology of γ-confidence β-content tolerance intervals. This profile assesses the validity of the method by comparing the method measurement uncertainty to a pre defined acceptance limit stating the maximum uncertainty suitable for the method under study. In this letter we comment on the response (T. Saffaj, B. Ihssane, Talanta 94 (2012) 361-362) these authors have made to our previous letter (E. Rozet, E. Ziemons, R.D. Marini, B. Boulanger, Ph. Hubert, Talanta 88 (2012) 769–771). In particular, we demonstrate that β-expectation tolerance intervals are prediction intervals, we show that β-expectation tolerance intervals are highly usefull for assessing analytical methods validation and for estimating measurement uncertainty and finally we show what are the differences and implications for these two topics (validation and uncertainty) when using either the methodology of β-expectation tolerance intervals or the γ-confidence β-content tolerance tolerance interval one. [less ▲]

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See detailValidation of analytical methods involved in dissolution assays: Acceptance limits and decision methodologies
Rozet, Eric ULg; Ziemons, Eric ULg; Marini Djang'Eing'A, Roland ULg et al

in Analytica Chimica Acta (2012), 751

Dissolution tests are key elements to ensure continuing product quality and performance. The ultimate goal of these tests is to assure consistent product quality within a defined set of specification ... [more ▼]

Dissolution tests are key elements to ensure continuing product quality and performance. The ultimate goal of these tests is to assure consistent product quality within a defined set of specification criteria. Validation of an analytical method aimed at assessing the dissolution profile of products or at verifying pharmacopoeias compliance should demonstrate that this analytical method is able to correctly declare two dissolution profiles as similar or drug products as compliant with respect to their specifications. It is essential to ensure that these analytical methods are fit for their purpose. Method validation is aimed at providing this guarantee. However, even in the ICHQ2 guideline there is no information explaining how to decide whether the method under validation is valid for its final purpose or not. Are the entire validation criterion needed to ensure that a Quality Control (QC) analytical method for dissolution test is valid? What acceptance limits should be set on these criteria? How to decide about method’s validity? These are the questions that this work aims at answering. Focus is made to comply with the current implementation of the Quality by Design (QbD) principles in the pharmaceutical industry in order to allow to correctly defining the Analytical Target Profile (ATP) of analytical methods involved in dissolution tests. Analytical method validation is then the natural demonstration that the developed methods are fit for their intended purpose and is not any more the inconsiderate checklist validation approach still generally performed to complete the filing required to obtain product marketing authorization. [less ▲]

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See detailCritical Review of Near-Infrared Spectroscopic Methods Validations in Pharmaceutical Applications
De Bleye, Charlotte ULg; Chavez, Pierre-François ULg; Mantanus, Jérôme ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2012), 69

Based on the large number of publications reported over the past five years, near-infrared spectroscopy (NIRS) is more and more considered an attractive and promising analytical tool regarding Process ... [more ▼]

Based on the large number of publications reported over the past five years, near-infrared spectroscopy (NIRS) is more and more considered an attractive and promising analytical tool regarding Process Analytical Technology and Green Chemistry. From the reviewed literature, few of these publications present a thoroughly validated NIRS method even if some guidelines have been published by different groups and regulatory authorities. However, as any analytical method, the validation of NIRS method is a mandatory step at the end of the development in order to give enough guarantees that each of the future results during routine use will be close enough to the true value. Besides the introduction of PAT concepts in the revised document of the European Pharmacopoeia (2.2.40) dealing with near-infrared spectroscopy recently published in Pharmeuropa, it agrees very well with this mandatory step. Indeed, the latter suggests to use similar analytical performance characteristics than those required for any analytical procedure based on acceptance criteria consistent with the intended use of the method. In this context, this review gives a comprehensive and critical overview of the methodologies applied to assess the validity of quantitative NIRS methods used in pharmaceutical applications. [less ▲]

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See detailUsefulness of capability indices in the framework of analytical methods validation
Bouabidi, Abderrahim ULg; Ziemons, Eric ULg; Marini Djang'Eing'A, Roland ULg et al

in Analytica Chimica Acta (2012), 714

Analytical methods capability evaluation can be a useful methodology to assess the fitness of purpose of these methods for their future routine application. However, care on how to compute the capability ... [more ▼]

Analytical methods capability evaluation can be a useful methodology to assess the fitness of purpose of these methods for their future routine application. However, care on how to compute the capability indices has to be made. Indeed, the commonly used formulas to compute capability indices such as Cpk, will highly overestimate the true capability of the methods. Especially during methods validation or transfer, there are only few experiments performed and, using in these situations the commonly applied capability indices to declare a method as valid or as transferable to a receiving laboratory will conduct to inadequate decisions. In this work, an improved capability index, namely Cpk-tol and the corresponding estimator of proportion of non conforming results ( ) has been proposed. Through Monte-Carlo simulations, they have been shown to greatly increase the estimation of analytical methods capability in particular in low sample size situations as encountered during methods validation or transfer. Additionally, the usefulness of this capability index has been illustrated through several case studies covering applications commonly encountered in the pharmaceutical industry. Finally a methodology to determine the optimal sample size required to validate analytical methods is also given using the proposed capability metric. [less ▲]

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See detailQuality by design compliant analytical method validation
Rozet, Eric ULg; Ziemons, Eric ULg; Marini Djang'Eing'A, Roland ULg et al

in Analytical Chemistry (2012), 84

The concept of quality by design (QbD) has recently been adopted for the development of pharmaceutical processes to ensure a predefined product quality. Focus on applying the QbD concept to analytical ... [more ▼]

The concept of quality by design (QbD) has recently been adopted for the development of pharmaceutical processes to ensure a predefined product quality. Focus on applying the QbD concept to analytical methods has increased as it is fully integrated within pharmaceutical processes and especially in the process control strategy. In addition, there is the need to switch from the traditional checklist implementation of method validation requirements to a method validation approach that should provide a high level of assurance of method reliability in order to adequately measure the Critical Quality Attributes (CQAs) of the drug product. The intended purpose of analytical methods is directly related to the final decision that will be made with the results generated by these methods under study. The final aim for quantitative impurity assays is to correctly declare a substance or a product as compliant with respect to the corresponding product specifications. For content assays, the aim is similar: making the correct decision about product compliance with respect to their specification limits. It is for these reasons that the fitness of these methods should be defined, as they are key elements of the Analytical Target Profile (ATP). Therefore, validation criteria, corresponding acceptance limits and method validation decision approaches should be settled in accordance with the final use of these analytical procedures. This work proposes a general methodology to achieve this in order to align method validation within the QbD framework and philosophy. β-expectation tolerance intervals are implemented to decide about the validity of analytical methods. The proposed methodology is also applied to the validation of analytical procedures dedicated to the quantification of impurities or active product ingredients (API) in drug substances or drug products and its applicability is illustrated with two case studies. [less ▲]

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See detailProtocole d'essai LC/MS - P001 - V01
Hubert, Cédric ULg; Ziemons, Eric ULg; Hubert, Philippe ULg

Report (2011)

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See detailEspectroscopia aplicada
Ziemons, Eric ULg; Frederich, Michel ULg; Fillet, Marianne ULg et al

Scientific conference (2011, May)

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See detailComparison between new and old excipients
Hubert, Cédric ULg; Ziemons, Eric ULg; Hubert, Philippe ULg

Report (2011)

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