Biopharmaceutical properties drugs

Fig. 7.5. The Biopharmaceutics Classification System (BCS) provides a scientific basis for predicting intestinal drug absorption and for identifying the rate-limiting step based on primary biopharmaceutical properties such as solubility and effective intestinal permeability (Pefr). BCS serves as a product control instrument. The BCS divides drugs into four different classes based on their solubility and...

Application of ultra-high-throughput in silico estimation of biopharmaceutical properties to the generation of rule-based computational alerts has the potential to improve compound selection to those drug candidates that are likely to prove less troublesome in their development. The extension of purely in silico methods to the realm of mechanistic simulation further enhances our ability to predict the impact of physiological and biochemical process on drug absorption and bioavailability. 

The design of pharmacokinetic studies that need to be conducted for product approval is a function of how much is known about the active drug moiety, its clinical pharmacokinetics, and the biopharmaceutical properties of the dosage form, and regulatory requirements. As a minimum,... 

Despite tremendous innovations in the field of drug delivery technology, oral intake remains the preferred route of drug administration, for reasons of patient convenience and therapy compliance. Compounds intended for oral administration must have adequate biopharmaceutical properties in order to achieve therapeutic concentrations at the targeted site of action. 

The parallel screening of drug candidates for their pharmacological activity and for their physicochemical and biopharmaceutical properties has become a major challenge in dmg development and is performed at very early stages... 

The dosage-form design is guided by the properties of the drug candidate. If an NCE does not have suitable physical and chemical properties or pharmacokinetic attributes, the development of a dosage form (product) may be difficult and may sometimes be even impossible. Any heroic measures to resolve issues related to physicochemical and biopharmaceutical properties of drug candidates add to the time and cost of drug... 

Aqueous solubility is probably the single most important biopharmaceutical property that pharmaceutical scientists are concerned with. It has been the subject of computational prediction for several years.20 23 The overall accuracy of the predicted values can be expected to be in the vicinity of 0.5 to 1.0 log units (a factor of 3 to 10) at best. Although a decision on acceptance or rejection of a particular compound cannot be made only on the basis of predicted parameters, these predictions may be helpful to direct chemical libraries with improved drug-like properties.24... 

Small-scale in vitro test systems may now be employed to assess biopharmaceutical properties or the drug s potential behaviour after in vivo administration. For example, drug penetration through monolayers of epithelial cells in tissue culture can be used to examine bioavailability. The drug s metabolism can be studied in vitro using hepatic microsomes and potentially toxic metabolites identified before problems arise in vivo Although not absolute, these tests... 

The cephamycins comprise a set of beta lactamase resistant fermentation products that consist of cephalosporins that include a methoxy group on the carbon bearing the amine. These agents were not suitable as drugs in their own right because of their poor biopharmaceutical properties. This was due to the circumstance that the natural products, like the original cephalosporins, occurred as their highly... 

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