Dosage forms specific

In addition, eertain eompendial requirements for content and delivered dose uniformity should be measured. The USP and EP propose that the total aerobic count not exceed 100 CFU/g (colony-forming imits) that the total yeast and mold counts not exceed 10 CFU/g and that no specific pathogens be detectable. Specifications for the other attributes should be based on the intended use and the historical performance of the product. As with other dosage forms, specifications must be met throughout the intended shelf life of the product. 

Unlike many dosage form specifications, the sterility specification is an absolute value. A product is either sterile or nonsterile. Historically, judgment of sterility has relied on an official compendial sterility test however, end-product sterility testing suffers from a myriad of limitations [1-4], The most obvious limitation is the nature of the sterility test. It is a destructive test thus, it depends on the statistical selection of a random sample of the whole lot. Uncertainty will always exist as to whether or not the sample unequivocally represents the whole. If it were known that one unit out of 1000 units was contaminated (i.e., contamination rate = 0.1%) and 20 units were randomly sampled out of those 1000 units, the probability of that one contaminated unit being included in those 20 samples is 0.02 [5], In other words, the chances are only 2% that the contaminated unit would be selected as part of the 20 representative samples of the whole 1000-unit lot. 

Non-destructive tests In addition, depending on the dosage form, specific tests as uniformity of dosage units or deviation between theoretical and average weight may be included. 

Even without administration in a pharmaceutical dosage form, specificity is imparted by choice of the area illuminated. Hydrophobicity of photosensitizers has been used to prepare self-assembled nanostructures that act in primary tumor targeting, after irradiation that induces destruction of the nanostructure and burst release of photosensitizer for maximal PDT [141]. 

To avoid confusion, several researchers have incorporated therapeutic intention into the definition of controlled release (4—7). Thus, controUed-release pharmaceuticals release dmgs in vivo according to a predictable, therapeutically rational, programmed rate to achieve the optimal dmg concentration in the minimal time (4). Specification by release rate complements specification by quantity jointly considered, they fix the duration of dmg release. Therefore, the dmg s duration of action can become a design property of a controlled release dosage form rather than an inherent pharmacokinetic property of the dmg molecule. 

Scope of Inspection Short description of the inspection (Product related, process related inspection and/or General GMP inspection, reference to specific dosage forms where appropriate). The reason for the inspection should be specified (e.g. new marketing application, routine, investigation of product defect. 

Comprehensive physicochemical characterization of any raw material is a crucial and multi-phased requirement for the selection and validation of that matter as a constituent of a product or part of the product development process (Morris et al., 1998). Such demand is especially important in the pharmaceutical industry because of the presence of several compounds assembled in a formulation, such as active substances and excipients, which highlights the importance of compatibility among them. Besides, variations in raw materials due to different sources, periods of extraction and various environmental factors may lead to failures in production and/or in the dosage form performance (Morris et al., 1998). Additionally, economic issues are also related to the need for investigating the physicochemical characteristics of raw materials since those features may determine the most adequate and low-cost material for specific procedures and dosage forms. 

Azathioprine was originally approved by the FDA in 1968 as an adjunct immunosuppressant for use in renal transplant recipients. It is available in oral and IV dosage forms.11 Prior to the advent of cyclosporine, the combination of azathioprine and corticosteroids was the mainstay of immunosuppressive therapy. Over the past 10 years, the use of azathioprine has declined markedly due in large part to the success of the MPA derivatives, which are more specific inhibitors of T cell proliferation. 

Often it is unnecessary to calculate an exact value for an absorption rate constant. For example, when several oral tablets containing the same drug substance are all found to be completely absorbed, it may be sufficient to merely determine if the absorption rates are similar to conclude that the products would be therapeutically equivalent. In another instance, it would be possible to choose between an elixir and a sustained-release tablet for a specific therapeutic need without assigning accurate numbers to the absorption rate constant for the two dosage forms. 

Concern for the physical and chemical integrity of topical systems is no different than for other dosage forms. However, there are some unique and germane dimensions to stability associated with semisolid systems. A short list of some of the factors to be evaluated for semisolids is given in Table 12. All factors must be acceptable initially (within prescribed specifications), and all must remain so over the stated lifetime for the product (the product s shelf life). 

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