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Microemulsions gastrointestinal absorption

WA Ritschel. Microemulsions for improved peptide absorption from the gastrointestinal tract. Methods Find Exp Clin Pharmacol 13 205-220, 1991. [Pg.287]

A formulation of ciclosporin (Sandimmun Neoral, Novartis) incorporates the drug in a preconcentrate which forms a microemulsion on dilution in aqueous fluids. This formulation offers an alternative to the oil formulation of ciclosporin (Sandimmun) which in vivo would be emulsified by bile salts and pancreatic enzymes. The residence time of ciclosporin in the gastrointestinal tract is shorter and the rate of absorption is faster with the microemulsion formulation (Fig. 7.19). [Pg.247]

To overcome the pharmacokinetic problems of CSA, a microemulsion formulation was developed. Both forms are available commercially in the United States, referred to as cyclosporine, USP and cyclosporine, USP [MODIFIED]. The two formulations are not bioequivalent and should not be used interchangeably. The microemulsion formulation is self-emulsifying and forms a microemulsion spontaneously with aqueous fluids in the gastrointestinal tract, making it less dependent on bile for absorption. The result is a sig-niflcantly greater rate and extent of absorption and decreased intraindividual variability in pharmacokinetic parameters. Bioavailability is enhanced owing to better dispersion and absorption and does not require bile excretion. The relative bioavailability of the microemulsion formulation is 60%. Peak concentrations generally are reached within 1.5 to 2 hours after oral administration. The terminal half-life is 8.4 hours. [Pg.1623]

Microemulsions are transparent systems of two immiscible fluids, stabilized by an interfacial film of surfactant or a mixture of surfactants, frequently in combination with a cosurfactant. These systems could be classified as water-in-oil, bicontinuous, or oil-in-water type depending on their microstructure, which is influenced by their physicochemical properties and the extent of their ingredients. - SMEDDSs form transparent microemulsions with a droplet size of less than 50 nm. Oil is the most important excipient in SMEDDSs because it can facilitate self-emulsification and increase the fraction of lipophilic drug transported through the intestinal lymphatic system, thereby increasing absorption from the gastrointestinal tract. Long-chain and medium-chain... [Pg.1117]


See other pages where Microemulsions gastrointestinal absorption is mentioned: [Pg.1562]    [Pg.628]    [Pg.414]    [Pg.1366]    [Pg.595]    [Pg.1563]    [Pg.277]    [Pg.259]    [Pg.8]    [Pg.18]   
See also in sourсe #XX -- [ Pg.1562 ]




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Gastrointestinal absorption

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