Additives additive, formulation, definitions

Conversion into a dimensionless formulation follows the same principle and notations as in the preceding sections with, in addition, the following definitions ... 

The major routes of parenteral administration of drugs are subcutaneous, intramuscular, and intravenous. Other more specialized routes are intrathecal, in-tracistemal, intra-arterial, intraspinal, intraepidural, and intradermal. The intradermal route is not typically used to achieve systemic drug effects. The major routes will be discussed separately. Definitions of the more specialized routes, along with additional information concerning needle sizes, volumes typically administered, formulation constraints, and types of medication administered, are summarized in Table 1. 

Phase IV. Studies or trials conducted after a medicine is marketed to provide additional details about the medicine s efficacy or safety profile. Different formulations, dosages, durations of treatment, medicine interactions, and other medicine comparisons may be evaluated. New age groups, races, and other types of patients can be studied. Detection and definition of previously unknown or inadequately quantified adverse reactions and related risk factors are an important aspect of many Phase IV studies. If a marketed medicine is to be evaluated for another (i.e., new) indication, then those clinical trials are considered Phase II clinical trials. The term postmarketing surveillance is frequently used to describe those clinical studies in Phase IV (i.e., the period following marketing) that are primarily observational or nonexperimental in nature, to distinguish them from well-controlled Phase IV clinical trials or marketing studies. 

Most drugs that are prescribed to us are formulated with active pharmaceutical ingredients and excipients. The formulations of selected drugs are presented in Exhibit 5.11. According to the US Pharmacopoeia and National Formulary definition, excipients are any component, other than the active substance(s), intentionally added to the formulation of a dosage form. There are many reasons for the addition of excipients ... 

However, in this formulation, G /8 is simply a fitted parameter, since there is no rigorous molecular definition for this form of the interfacial energy. In addition, this model suffers the same problem as do other continuum models, in that it contains parameters that must be determined from experimental data and that cannot be estimated a priori from molecular techniques. 

The US Environmental Protection Agency (USEPA 1998) describes problem formulation as an iterative process with 4 main components integration of available information, definition of assessment endpoints, definition of conceptual model, and development of an analysis plan. These 4 components apply also to probabilistic assessments. In addition, it is useful to emphasize the importance of a 5th component dehnition of the assessment scenarios. The relationships between all 5 components are depicted in Figure 2.1. Note that the bidirectional arrows represent the interdependency of the different components and imply that they may need to be revised iteratively as the formulation of the problem is rehned. 

Pyrotechnics are invariably intimate mixtures of finely powdered fuels and oxidizers together with other additives in order to impart special effects depending on the requirement. Pyrotechnic formulations burn very rapidly when ignited as a loose powder. However, there are some applications where controlled steady burning is required for a definite time and this is achieved by compressing the mixture into columns surrounded by a relatively non-combustible material so that combustion proceeds from one end to other, layer by layer for a long duration. 

When I speak of product formulation and design, I refer to the systematic identification of the molecular structure or material formulation that would meet a specifically defined need. In other words, you know what you want, but you don t know what structure or formulation will take you there. This fairly broad definition is applicable to a wide variety of situations. For example, engineering materials, polymer composites, catalysts and fuel additives, agrochemicals, and pharmaceutical problems all fit into this framework. 

---