Generic Formulation

These equations describe the coupled phenomena between diffusion and viscous stresses, existing, for example, in diffusion of small molecules in polymer matrix. Other possible couplings occur in shear-induced diffusion and shear-induced separation. 

If Pv is the sum of various viscous pressure contributions P/, each of them with its own relaxation time t2 Eq. (14.61) becomes 

By neglecting diffusion effects, integration of the above equation yields 

GENERIC was formulated by Grmela and Ottinger (1997). The time evolution of the physical systems may be written in terms of two generators E and S and two matrices L and M to represent the essential features of the dynamics of 

Equation (14.76) requires the following general and essential degeneracy conditions  

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It is seen that to identify the impurities, the column appeared to be significantly overloaded. Nevertheless, the impurities were well separated from the main component and the presence of a substance was demonstrated in the generic formulation that was not present in the Darvocet . The mobile phase was 98.5% dichloromethane with 1.5% v/v of methanol containing 3.3% ammonium hydroxide. The ammoniacal methanol deactivated the silica gel but the interaction of the solutes with the stationary phase would still be polar in nature. In contrast solute interactions with the methylene dichloride would be exclusively dispersive. 

Furosemide and bumetanide are both available in generic formulations and are generally less expensive than torsemide. 

E. To be approved, generic formulations must exhibit the same rate and extent of absorption as the trademark compound. All of the other choices can affect drug absorption. For example, slowing gastric emptying time may increase the absorption of a... 

The other computation is that of relative bioavailability. This calculation is determined when two products are compared to each other, not to an intravenous standard. This is commonly calculated in the generic drug industry to determine that the generic formulation (e.g., a tablet) is bioequivalent to the original formulation (e.g., another tablet). Thus, bioavailability is not routinely calculated in an individual patient but reserved for product development by a drug manufacturer. However, it is important to have an idea of how formulations or routes of administration differ with respect to bioavailability so as to allow proper dosage adjustment when changing formulations or routes of administration. 

In many circumstances, generic substitution is a safe and effective cost-saving tool, but the clinician should be aware of potential problems and, in the event of an unexpected reaction, should ask the patient if the medication has changed in appearance. A change in size, shape, or color, for example, should alert the clinician to a probable change in generic formulation. 

This chapter introduces the reader to elementary concepts of modeling, generic formulations for nonlinear and mixed integer optimization models, and provides some illustrative applications. Section 1.1 presents the definition and key elements of mathematical models and discusses the characteristics of optimization models. Section 1.2 outlines the mathematical structure of nonlinear and mixed integer optimization problems which represent the primary focus in this book. Section 1.3 illustrates applications of nonlinear and mixed integer optimization that arise in chemical process design of separation systems, batch process operations, and facility location/allocation problems of operations research. Finally, section 1.4 provides an outline of the three main parts of this book. 

This book aims at presenting the fundamentals of nonlinear and mixed-integer optimization, and their applications in the important area of process synthesis and chemical engineering. The first chapter introduces the reader to the generic formulations of this class of optimization problems and presents a number of illustrative applications. For the remaining chapters, the book contains the following three main parts ... 

Form 2 impurities. The court ruled in favor of Novopharm. Novopharm was allowed to develop a generic formulation of Form 1 of ranitidine with a target market date of 1995, the expiration date of the Form 1 patent. 

An ANDA relies heavily on the previously approved NDA for evidence of efficacy and ultimate safety and concentrates instead on the manufacturing issues related to the specific generic formulation. Specifically, the ANDA focuses on three areas Formulation and manufacturing, container integrity... 

Drug therapy is the most common initial treatment and is initiated in a stepwise manner, starting with a single well tolerated topical agent (Table 66-2). Historically, )3-blockers (e.g., timolol) were the treatment of choice and continue to be used if there are no contraindications to potential P-blockade caused by systemic absorption. Blockers have the advantage of low cost owing to generic formulations. 

A more significant side effect has been reported with topical diclofenac ophthalmic solntion. Keratolysis (corneal melting) was associated with a small nnmber of cases in high-risk patients after ophthalmic snrgery. Responsibility for this side effect has been attribnted subsequently to the vitamin E-based solnbilizer/preserva-tive in the generic formulation, which has been withdrawn from the marketplace. 

Because of its large number of empirical parameters, this model can be fitted to a variety of fuels and can reproduce the important autoignition phenomena. This is accomplished with only a modest computational requirement and, consequently, it has been used in a number of engine modelling studies over the past 20 years. Its main deficiencies are the difficulty of extending it to new fuels (which has been done only by the original authors) and its still limited representation of the real chemistry. Because of the generic formulation, the species are rather ill-defined. It would be difficult to use, for instance, in a study of chemical octane requirement increase, discussed in Section 7.5.2. 

Generic substitution, where a generic formulation (p. 85) is substituted (by a pharmacist) for the proprietary formulation prescribed by the doctor. 

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