Quality control formulations

QUALITY CONTROL OF AGROCHEMICAL FORMULATIONS BY DIFFUSE REFLECTANCE NEAR INFRARED SPECTROMETRY... 

A solvent free, fast and environmentally friendly near infrared-based methodology was developed for the determination and quality control of 11 pesticides in commercially available formulations. This methodology was based on the direct measurement of the diffuse reflectance spectra of solid samples inside glass vials and a multivariate calibration model to determine the active principle concentration in agrochemicals. The proposed PLS model was made using 11 known commercial and 22 doped samples (11 under and 11 over dosed) for calibration and 22 different formulations as the validation set. For Buprofezin, Chlorsulfuron, Cyromazine, Daminozide, Diuron and Iprodione determination, the information in the spectral range between 1618 and 2630 nm of the reflectance spectra was employed. On the other hand, for Bensulfuron, Fenoxycarb, Metalaxyl, Procymidone and Tricyclazole determination, the first order derivative spectra in the range between 1618 and 2630 nm was used. In both cases, a linear remove correction was applied. Mean accuracy errors between 0.5 and 3.1% were obtained for the validation set. 

Quality control of product, both as the surfactant itself and in the surfactant-containing formulation... 

The in vitro release profiles of many microsphere formulations including steroids can be determined by an ethanol/water model (74). By adjusting the ethanol/water ratio in the receiving fluid, the rate and duration of release can be optimized to afford a rapid evaluation tool for developmental and quality control purposes. The model is not intended to have one-to-one correlation with in vivo results. 

On most occasions CRMs are used as Quality Control materials, rather than as calibrations . As outlined above, this common application adds significantly to the user s uncertainty budget, since at a minimum it is necessary to consider at least two independent measurement events (Um). so increasing the combined uncertainty of the results. Again this process rapidly increases the combined uncertainty with increasing complexity of the analytical system and so the usefulness of a control analysis may be downgraded when a correct uncertainty budget is formulated. 

As indicated in Section 6.2.2, DI-CIMS suffers from poor reproducibility. For nonvolatile additives that do not evaporate up to 350 °C, direct quantitative analysis by thermal desorption is not possible. The method depends on polymer formulation standards that are reliably mixed. Wilcken and Geissler [264] described rapid quality control of l- xg paint samples by means of temperature-programmable DI-EIMS with PCA evaluation. 

Applications X-ray fluorescence is widely used for direct examination of polymeric materials (analysis of additives, catalyst residues, etc.) from research to recycling, through production and quality control, to troubleshooting. Many problems meet the concentration range in which conventional XRF is strong, namely from ppm upwards. Table 8.42 is merely indicative of the presence of certain additive classes corresponding to elemental analysis element combinations are obviously more specific for a given additive. It should be considered that some 60 atomic elements may be found in polymeric formulations. The XRF technique does not provide any structural information about the analytes detected the technique also has limited utility when... 

Workplace safety has been taken care of by the reworking of some classes of additives into more environmentally acceptable forms. Some trends are the increased use of additive concentrates or masterbatches and the replacement of powder versions by uniform pellets or pastilles which release less dust and flow more easily. Moreover, the current move to multicomponent formulations of stabilisers and processing aids in a low- or nondusting product also takes away the risk of operator error, aids quality control, ISO protocols and good housekeeping. An additional benefit is more homogeneous incorporation of the additives in the polymeric matrix. 

Contracting out of activities previously only conducted in-house is already becoming quite common and will probably continue to develop. In the past a so-called full-service pharmaceutical company took direct responsibility for all the activities required for the formulation, manufacture, quality control, and regulatory approval of its drug products. Nowadays the use of specialist contract houses to perform activities such as formulation, analytical methods development, manufacture of clinical trials supplies, supervision of the assembly of an NDA, postmarketing surveillance, and even troubleshooting may be contracted for even by some of the largest companies. 

Good Manufacturing Practices for Pharmaceuticals A Plan for Total Quality Control, Second Edition, Revised and Expanded, Sidney H. Willig, Murray M. Tuckerman, and William S. Hitchings IV Formulation of Veterinary Dosage Forms, edited by Jack Blodinger Dermatological Formulations Percutaneous Absorption, Brian W. Barry... 

Drug Products for Clinical Trials An International Guide to Formulation Production Quality Control, edited by Donald C. Monkhouse and Christopher T. Rhodes... 

F. Clarke, A. Whitley, S. Mamedov, F. Adar, N. Lewis and E. Lee, A comparison of Raman and EDXRF chemical imaging for use in formulation process development and quality control, Newsletters, Raman Update (Horiba Jobin Yvon), Spring, 2005. 

Advances in quality control requirements for rubber compounds have demanded that special care is exercised in the weighing of the various fillers and critical small volume powders necessary for the formulation. Ingredient weighing systems are available which can be tailored to the specific requirements of individual factories. Additional components can include conveyors, bagging units and pneumatic conveyance systems. 

Evaluation of the dissolution rates of solid drugs is extremely important in the development, formulation, and quality control of solid pharmaceuticals. The... 

The original applications of NIR were in the food and agricultural industries where the routine determination of the moisture content of foodstuffs, the protein content of grain and the fat content of edible oils and meats at the 1% level and above are typical examples. The range of industries now using the technique is much wider and includes pharmaceutical, polymer, adhesives and textile companies. The first in particular are employing NIR spectrometry for the quality control of raw materials and intermediates and to check on actives and excipients in formulated products. Figure 9.26(b) demonstrates that even subtle differences between the NIR spectra of enantiomers can be detected. 

Since surfactants are commercially produced by means of large-scale chemical processes, complex mixtures of homologues and isomeric compounds, e.g. non-ionics of the alkylethoxylate type that may differ in length of alkyl as well as polyether chains, can result. The determination and differentiation of the products in quality control during production and trade is a somewhat easier task. However, more difficulties arise in the analysis of the compounds of these mixtures and formulations in environmental samples. 

It should be remembered that in 1970, when drug-release/dissolution tests first became official through the leadership of USP and NF, marketed tablets or capsules in general simply did not have a defined dissolution character. They were not formulated to achieve a particular dissolution performance, nor were they subjected to quality control by means of dissolution testing. Moreover, the U.S. Food and Drug Administration (FDA) was not prepared to enforce dissolution requirements or to even to judge their value. 

Dissolution is also used to identify bioavailability (BA) problems and to assess the need for further BE studies relative to scale-up and post-approval Changes (SUPAC), where it functions as a signal of bioinequivalence. In vitro dissolution studies for all product formulations investigated (including prototype formulations) are encouraged, particularly if in vivo absorption characteristics can be defined for the different product formulations. With such efforts, it may be possible to achieve an in vitro/in vivo correlation. When an in vitro correlation or association is available, the in vitro test can serve not only as a quality control (QC) specification for the manufacturing process, but also as an indicator of in vivo product performance. 

In general, it is preferable to choose excipients and processes for IR dosage forms that do not result in a formulation that requires a particular pH to function well. In the general population, the pH in the stomach is quite variable (see the subsection Choice of Dissolution Test Conditions for Quality Control ) and there is no guarantee that the dosage form will be exposed to acid, so dosage forms that require acid to facilitate release are unlikely to perform robustly in the clinical practice setting. 

In such cases, it is obviously advantageous to use biorelevant dissolution tests to characterize the drug substance, to compare formulations and to make a preliminary assessment of possible food effects. However, for routine quality control work, the manufacture of media containing bile components is not only rather time-consuming but may also present difficulties in terms of quality assurance and validation of the raw materials, as is the case with many chemicals obtained from natural sources. 

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