Formulation quality aspects

Development activities encompass drug substance characterization, formulation design, packaging selection, and process development for manufacturing. Each of these aspects influence the lyophilization process. For a drug substance, upstream processing and quality aspects of the starting material need to be quantified. These quality aspects include both assay and purity. In particular, levels of... 

The texture of traditional and novel formulated foods, its formation, modification, and/or preservation during processing (frying, cooking, freezing, etc.) and storage is one of the key quality aspects. Food texture, therefore, is important for the success of a food both in the marketplace and for consumption. 

Our approach [265, 440, 445] enhances the simple selection mechanism of the CORBA trader to consider QoS. Here, an importer (which is the client using a trader to search for a service) describes a service by service tjrpe and service properties as before, but it is possible to specify roles for several values of the same property, namely a target value for the property, a lower bound (minimum acceptable quality) and an upper bound (maximum useful quality). This enhancement allows a client to formulate wishes and limits on service properties, see Fig. 4.16. Additionally, preferences for specifying the importance of properties can be expressed. These values, describing different aspects for the same quality criterion, are called Service Request Property. The importer can specify a whole vector of such properties to express its complete requirements on a service through different QoS aspects. In a similar way, a server offering a service can describe its limitations and capabilities by expressing upper and lower bounds for the quality aspects it can deliver. 

It is only the first class of applications to which this chapter is devoted, because these computations require the highest quality of random numbers. The ability to do a multidimensional integral relies on properties of uniformity of n-tuples of random numbers and/or the equivalent property that random numbers be uncorrelated. The quality aspect in the other uses is normally less important simply because the models are usually not all that precisely specified. The largest uncertainties are typically due more to approximations arising in the formulation of the model than those caused by lack of randomness in the random number generator. 

In the field of analytical chemistry and pharmaceutical formulations there is a growing awareness of quality issues. To mention a few. Good Laboratory Practice (GLP) and Good Manufacturing Practice (GMP) and ISO norms are important topics in both laboratory and industrial environments. Moreover, there is a growing number of regulatory committees concerned with all aspects of quality, both on a national and international level [1-3]. 

In pharmaceutical technology, it is important to develop formulations which are robust to environmental conditions, like temperature changes and relative humidity variation, and that have a long life time. These aspects belong to the quality assurance of pharmaceutical formulations. 

Peroxidation and free-radical formation should be considered as important aspects of pharmaceutical stability and quality of parenteral nutriton and intravenous drugs. Peroxidation and free-radical formation depend on environmental factors, such as storage conditions and container material, but are also influenced by formulation components or additives such as tocopherols and metabisulfite. Since the generation of these harmful species occurs generally at the time of use, manufacturing quality controls fail in demonstrating their existence. 

Some important aspects of foam are not included in this list. We mentioned void volume earlier. This parameter is related to density by a comparison of bulk density to absolute density. We will discuss each of these measures of foam quality and relate their applicability to the theme of this book. Later in the chapter we will show how formulation and processing techniques are used to adjust and control the most important parameters. 

Although BA studies have many pharmacokinetic objectives beyond formulation performance as described above, it should be noted that subsequent sections of this guidance focus on using relative BA (referred to as product quality BA) and, in particular, BE studies as a means to document product quality. In vivo performance, in terms of BA/BE, may be considered to be one aspect of product quality that provides a link to the performance of the drug product used in clinical trials and to the database containing evidence of safety and efficacy. 

Which quality attributes need to be built into the dosage form Dose accuracy, content uniformity, purity and stability are aspects to be evaluated, all of which are of particular interest to the scientist developing low-dose formulations. 

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