Chemometric designs

Chemometric Design Expert software was used to generate and manipulate the factorial data Neural network was carried out using the back propagation algorithm (WEKA) ... 

Several studies have employed chemometric designs in CZE method development. In most cases, central composite designs were selected with background electrolyte pH and concentration as well as buffer additives such as methanol as experimental factors and separation selectivity or peak resolution of one or more critical analyte pairs as responses. For example, method development and optimization employing a three-factor central composite design was performed for the analysis of related compounds of the tetracychne antibiotics doxycycline (17) and metacychne (18). The separation selectivity between three critical pairs of analytes were selected as responses in the case of doxycycline while four critical pairs served as responses in the case of metacychne. In both studies, the data were htted to a partial least square (PLS) model. The factors buffer pH and methanol concentration proved to affect the separation selectivity of the respective critical pairs differently so that the overall optimized methods represented a compromise for each individual response. Both methods were subsequently validated and applied to commercial samples. 

TABLE 4.2. Examples of CE methods for the determination of related componnd optimized hy chemometric design... 

Drug CE Mode Chemometric Design Studied Eactors Optimized Responses Reference... 

TABLE 5.1. A summary of factors, responses, chemometric designs and methods, and validation criteria nsed by different gronps for the optimization of the separation of varions samples by MEKC... 

Sample Factors Response Chemometric Designs and Methods Validation Reference... 

Drewry D H and S S Young 1999. Approaches to the Design of Combinatorial Libraries. Chemometrics in Intelligent Laboratory Systems 48 1-20. 

History and Objectives of Quantitative Drug Design. In Hansch C, P G Sammes and J B lor (Editors) Comprehensive Medicinal Chemistry Volume 4. Oxford, Pergamon Press, pp. 1-31. emd H van de 1995. Chemometric Methods in Molecular Design. Weinheim, VCH Publishers. 

Note These equations are from Doming, S. N. Morgan, S. L. Experimental Design A Chemometric Approach. Elsevier Amsterdam, 1987, and pseudo-three-dimensional plots of the response surfaces can be found in their figures 11.4, 11.5, and 11.14. The response surface for problem (a) also is shown in Color Plate 13. 

Deming, S. N. Morgan, S. L. Experimental Design A Chemometric Approach. Elsevier Amsterdam, 1987. 

Morgan, E. Chemometrics Experimental Design. John Wiley and Sons Chichester, England, 1991. 

S. N. Denting and S. L. Morgan, Experimental Design A Chemometric Approach Elsevier Science Publishing Co., Inc., Amsterdam, The Netherlands, 1987. D. D. Wolff and M. L. Parsons, Pattern Recognition Approach to Data Interpretation Plenum Press, New York, 1983. 

Mathews and Rawlings (1998) successfully applied model-based control using solids hold-up and liquid density measurements to control the filtrability of a photochemical product. Togkalidou etal. (2001) report results of a factorial design approach to investigate relative effects of operating conditions on the filtration resistance of slurry produced in a semi-continuous batch crystallizer using various empirical chemometric methods. This method is proposed as an alternative approach to the development of first principle mathematical models of crystallization for application to non-ideal crystals shapes such as needles found in many pharmaceutical crystals. 

H. van de Waterbeemd, ed., QSAR Chemometric Methods in Molecular Design. VCH, Weinheim, 1995. 

As we have stated in the introduction to this chapter and as appears from this overview, a wide variety of chemometric methods converges in QSAR, which plays a key role in the design of novel and improved drugs. 

Volume 3 Experimental Design A Chemometric Approach, by S.N. Deming and S.L. Morgan... 

Sharaf MA, Illman DL, Kowalski BR (1986) Chemometrics. Wiley, New York Williams CS (1986) Designing digital filters. Prentice Hall, New York Wolf D (1999) Signaltheorie. Springer, Berlin Heidelberg New York... 

Deming SN, Morgan SL (1993) Experimental design a chemometric approach, 2nd edn. Elsevier, Amsterdam... 

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