Formulation of biphasic release tablets containing slightly soluble drugs.

A new biphasic release system for slightly soluble drugs has been proposed. To enhance the dissolution rate, the drug was milled with a superdisintegrant. Then, double-layer tablets were prepared.

Formulation and characterization of calcium alginate beads containing ampicillin.

The purpose of this work was the preparation and characterization of calcium alginate beads containing ampicillin. Aqueous solutions of drug and sodium alginate (three viscosity grades) were added drop by drop to aqueous solutions of calcium chloride; the droplets instantaneously formed gel beads, which were then dried. Morphological studies and drug contents, in vitro release, and erosion tests were carried out for the characterization of the prepared beads.

Differences between dynamic and equilibrium surface tension of poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) block copolymer surfactants (poloxamers P407, P237, and P338) in aqueous solution.

Poloxamer surfactants are macromolecules with complex interfacial behavior. Although a number of studies of equilibrium surface tension have been published recently, there is little information on the diffusion of these large molecules to the air-liquid interface. Because most surfactants are used in dynamic systems, the diffusion to the surface can be critical in controlling performance.