Formulation development defined

Powder flow is most frequently thought of as relevant to formulation development, and there are numerous references attempting to correlate any one of a number of measures of powder flow to the manufacturing properties of a formulation [34—40]. In particular, the importance of physical properties in affecting powder flow has been well documented. Research into the effect of the mechanical properties on powder flow has, however, been very limited. It is, of course, important to be able to determine and quantitate the powder flow properties of formulations. It is of equal importance, however, to determine the powder flow characteristics of bulk drug early in the development process (preformulation phase). Often, the preformulation or formulation scientist is constrained by time, materials, and manpower. Yet certainly the preformulation studies carried out should be meaningful. Well-defined experimental methods and procedures should be used the information generated should be reproducible and permit useful predictions to be made. 

In formulation development, the octanol-water partition coefficient is commonly used it is defined as ... 

Although proven useful for formulation development, the various defined indices and associated mechanical and physical properties have not been shown to be able to conclusively predict scale-up performance of... 

Define production time line for drug substance supplies for formulation development, stability, toxicology, and clinical studies. 

Level C IVIVC presents anyway some interest as defined in the FDA note for guidance A single point Level C correlation allows a dissolution specification to be set at the specified time point. While the information may be useful in formulation development, waiver of an in vivo bioequivalence study (biowaiver)... 

Parenteral is defined as situated or occurring outside the intestine, and especially introduced otherwise than by way of the intestines —pertaining to essentially any administration route other than enteral. This field is obviously too broad for an adequate focus in one book, let alone one chapter. Many have nonetheless used the term synonymously with injectable drug delivery. We restrict ourselves to this latter usage. This would thus include intravenous, intramuscular, subcutaneous, intrathecal, and subdural injection. In this chapter we discuss the theoretical and practical aspects of solubilizing small molecules for injectable formulation development and will examine the role of surfactants and other excipients in more recent parenteral delivery systems such as liposomes, solid-drug nanoparticles and particulate carriers. 

The planning and scoping process defined in the screening phase of the methodology are consistent with the problem formulation phase defined in the U.S. era s framework. For instance, problem identification, data gathering, selection of assessment endpoints and development of conceptual model and analysis plan are well described in the screening phase of the methodology. 

During early formulation development it is useful to have a constant, defined surface area exposed to the dissolution medium in order to compare dissolution rates of drug substances. Typically, intrinsic dissolution is carried out using a compressed disk of material with only one side exposed to the dissolution fluid. Comparison of intrinsic dissolution rate may be especially useful when characterizing different salts,... 

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