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Spray-freeze-drying for the Production of Therapeutic Nanoparticles
Published in S. Padma Ishwarya, Spray-Freeze-Drying of Foods and Bioproducts, 2022
Due to their poor aqueous solubility, many of the prospective candidate molecules are rejected during the initial stages of drug development. Classified as BCS Class II drugs (Biopharmaceutics Classification System), these poorly water-soluble APIs exhibit low bioavailability and limited absorption in the gastrointestinal tract, when administered orally. The common examples of BCS Class II drugs include danazol and carbamazepine. The major factors that influence the dissolution property of APIs are the particle size, specific surface area and degree of crystallinity. Specific surface area of a drug is directly related to its dissolution rate and bioavailability (Lindenbaum et al., 1973). But, as mentioned earlier, submicron and nanoscale particles need to be stabilized both physically and chemically. Many techniques have been commonly used to improve the dissolution rate of poorly water soluble APIs, including mechanical milling, spray drying, precipitation, and freeze-drying. But most of these techniques fail in preserving the stability of nanoparticles.
Preparation, Characterization and ex vivo Intestinal Permeability Studies of Ibuprofen Solid Dispersion
Published in Journal of Dispersion Science and Technology, 2019
Thais Francine Ribeiro Alves, Cecília Torqueti Barros, Denicezar Baldo, Venâncio Alves Amaral, Mirella Sever, Carolina Santos, Patrícia Severino, Marco Vinicius Chaud
The Biopharmaceutics Classification System (BCS) approaches three major factors that govern the rate and extent of absorption from solid oral dosage forms: dissolution, and gastrointestinal permeability. The BCS is classified into four classes: class I- highly soluble and highly permeable; class II - poorly soluble and highly permeable; class III - highly soluble and low permeable; class IV - poorly soluble and low permeable.[3]