Heat-Stable Dry Powder Oxytocin Formulations for Delivery by Oral Inhalation.

In this work, heat stable dry powders of oxytocin (OT) suitable for delivery by oral inhalation were prepared. The OT dry powders were prepared by spray drying using excipients chosen to promote OT stability including trehalose, isoleucine, polyvinylpyrrolidone, citrate (sodium citrate and citric acid), and zinc salts (zinc chloride and zinc citrate). Characterization by laser diffraction indicated that the OT dry powders had a median particle size of 2 μm, making them suitable for delivery by inhalation.

Structure of an alpha-Keto beta-Amido Acid, 3-(Phenylacetamido)pyruvic Acid, and Its Methyl Ester in the Solid State and in Organic and Aqueous Solvents.

3-(Phenylacetamido)pyruvic acid and its methyl ester both exist in the enol form in the solid state and when dissolved in organic solvents. In aqueous solution, the pK(a)'s of the enol acid are 3.28 (CO(2)H) and 10.