Biopharmaceutical solubility

Substance Characterisation Prior to Biopharmaceutical Solubility/Dissolution Tests... 

Fig. 12 Illustration of the Biopharmaceutical Classification System (BCS), which classifies drug absorption potential on the basis of aqueous solubility or membrane permeability. (Copyright 2000 Saguaro Technical Press, Inc., used with permission.)...

Drug instability as delivered from conventional formulation Solubility Biopharmaceutical Low absorption High membrane binding Biological instability Pharmacokinetic and pharmacodynamic Short half-life... 

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...

Based on their solubility and intestinal permeability characteristics, drugs have been classified into one of four categories according to the Biopharmaceutics Classification System (BCS) proposed by Amidon et al. [49]. 

Biopharmaceutics Classification System Redefining BSC Solubility Class Boundary... 

Tab. 8.2. Biopharmaceutics Classification System (BCS). BCS is a permeability and solubility classification.

Fig. 15.5. The biopharmaceutics classification system (BCS). Drug-like molecules are grouped into four BCS classes based on their solubility and permeability. A drug is regarded as a highly soluble compound if the maximum dose given orally is soluble in 250 mL fluid in the...

The example of amprenavir, an HIV-1 protease inhibitor, shows that intestinal metabolism can also be used as a strategy to enhance the bioavailability of compounds. In the biopharmaceutics classification system (BCS), amprenavir can be categorized as a class II compound it is poorly soluble but highly permeable [51]. Fosamprenavir, the water-soluble phosphate salt of amprenavir, on the other hand, shows poor transepithelial transport. However, after oral administration of fosamprenavir, this compound is metabolized into amprenavir in the intestinal lumen and in the enterocytes mainly by alkaline phosphatases, resulting in an increased intestinal absorption [51, 174],... 

Obata K, Sugano K, Machida M, Aso Y (2004) Biopharmaceutics classification by high throughput solubility assay and PAMPA. Drug Dev Ind Pharm 30 181-185. 

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... 

Since solubility and permeability are the two most important factors influencing oral absorption of drugs, the following biopharmaceutical classification system (BCS) for drug substances, based on the work by Amidon et al.,67 has been recommended by the FDA 68... 

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