Matrixing design

Bracketing and Matrixing Designs for Stability Testing of New Drug Substances and Products... 

ICH QID Bracketing and matrixing designs for stability testing of drug substances and drug products Step 5 (2002)... 

Each process owner requires a defined level of decision authority. This authority level delineates the bounds of decision making granted by the organization to the process owner. Business needs and risk assessment must be incorporated into the design of the decision authority granted to a process owner. Table 6 is an example of a decision authority matrix design for a process owner. It requires cross-functional management support to be effective. 

Matrixing design [10] may involve elimination of some stability sample pull time points to achieve reduced testing strategy. For example, a one-half reduction in time points eliminates one in every two time points from full study design, and one-third reduction eliminates one in every three time points. However, such a scenario must include full testing at initial, 12-month, and final time points under a 36-month shelf life study [10]. 

Applying a matrixing design on time points only, all factor combinations (full factorial design) should be tested at the initial and hnal points in time, while a... 

For this matrixing design, the total number of samples needed for the whole stability study is 3 x 18 + 5 x 12, or 114, compared to 216 samples needed for the full 3k design. Furthermore, for the case where both strength and packaging size have... 

A large part of the success of the combination of FI and atomic spectrometry is due to its ability to overcome interference effects. The implementation of some pretreatment chemistry in the FI format makes it possible to separate the species of the analyte from the unwanted matrix species e.g. by converting each sample into a mixture of analyte(s) and a standard background matrix, designed not to interfere in the atom formation process and/or subsequent interaction with radiation in the atom cell). Often such separation procedures result also in an increased analyte mass flux into the atom source with subsequent improvements in sensitivity and detection limits. 

A "matrix design" is a suitable way of obtaining all the treatment combinations implicated in a 2 factorial design, but it is not a handy system to notate... 

Once you have selected the factors to study, defined their low and high levels, constructed the matrix design and carried out the 2 runs in the laboratory, you should have obtained the corresponding 2 responses. Now, the interest is in evaluating the diiferent effects. 

Two algorithms are available to perform all the calculations in a very simple way, namely the Box, Hunter and Hunter (BH ) algorithm and Yates s algorithm. Both are considered below for a typical and simple example of a 2 factorial design. Assume we are studying the influence of pH (A), temperature (B) and time (C) over the yield (response in %) of the extraction of a metal from a complex analytical matrix, just before conducting the extracts to an ICP device. The levels of each factor, fixed by the analyst, are pH (A), 3 (—), 5(4-) temperature (B), 40 (-), 60 C ( + ) and time (C), 1 (-), 2h. (- -). The matrix design and the experimental data are as follows ... 

Table 2.4 Matrix design of a 2 fractional design. Generator C=AB.

Table 2.5 Plackett-Burman designs. First row of the matrix design.

Table 2.6 The eight runs of a Plackett-Burman matrix design. ...

FAAS A 2-level full design and a 2-Doehlert matrix design were... 

Cu by combining full factorial and Doehlert matrix designs... 

Doehlert matrix design to study an on-line pre-concentration procedure... 

Process analysis Process variables, matrix design, factorial design analysis... 

A matrix system consists of active and inactive ingredients that are homogeneously mixed in the dosage form. It is by far the most commonly used oral CR technology, and the popularity of matrix systems can be attributed to several factors. First, unlike reservoir and osmotic systems, products based on matrix design can be manufactured using conventional... 

Transdermal products with semisolid matrix design include Habitrol, Nitrodisc, Nitroglycerin Transdermal, and Prostep. For example, Habitrol consists of an impermeable backing laminate with a layer of adhesive and a nonwoven pad to which a nicotine solution is applied. Multiple layers of adhesive on a release liner are then laminated on the patch. The systems come in 10-, 20-, and 30-cm2 sizes corresponding to 7, 14, and 21 mg/day, respectively, delivered over 24 hours. 

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