Active pharmaceutical ingredient Permeability

The BCS is a scientific framework for classifying active pharmaceutical ingredients based upon their aqueous solubility and intestinal permeabihty. When combined with the dissolution of the pharmaceutical product, the BCS takes into account three major factors that govern the rate and extent of drug absorption (exposure) from immediate-release oral solid dosage forms dissolution, solubility, and intestinal permeability. 

Eligibility for the biowaiver procedure based on solubility and permeability characteristics of the active pharmaceutical ingredient... 

Some drug absorption enhancers are capable of loosening tight junctions (zonula occludens) and thereby facilitate paracellular absorption of drug molecules and improve the bioavailability of active pharmaceutical ingredients with low membrane permeability. The penetration enhancers include chelating agents [e.g., ethylenediaminetetraacetic acid), toxins [e.g., zonula occludens toxin), plant-derived materials [e.g., aloe vera gel), and cationic polymers. Polycationic lipophilic-core dendrons, which form lipophilic ion-pairs with heparin, were studied as a system for oral delivery of heparin. ... 

Oxygen permeability is a measure of the effectiveness of the coating material to act as a barrier to oxygen and is especially important when working with active pharmaceutical ingredients that can be degraded by oxidative... 

Gradual diffusion of an active ingredient through a permeable or soluble coating. Pelleted products such as fertilizers and medicinals are often covered with a layer of a substance that permits slow and uniform escape of the active principle. Sulfur is used to coat controlled-release fertilizers gelatin and similar materials serve the same purpose in pharmaceuticals. 

Many plants, used as spices or flavor ingredients, are preserved by drying and are ideal matrices for SFE. Once ground to a powder, they have a large surface area and are highly permeable, leading to rapid and efficient extractions. Interest in SFE of plants has principally been for the isolation of essential oils, but recently SFE has also been used to obtain pharmaceutically active compounds. The extraction of the sesquiterpene lactone parthenolide (Fig. 5) from feverfew plants has been described by Smith (30) and Smith and Burford (31). SFE was compared with steam distillation and solvent extraction. While SFE extracted the less-volatile lactones and parthenolide, the steam distillation extracted the volatile terpenes. SFE resulted in incomplete extraction compared... 

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