ABSTRACT
The purpose of this study was to prepare excipient-free porous microparticles of bendroflumethiazide by spray drying and to characterise the physicochemical properties of the particles produced. Solutions of bendroflumethiazide in ethanol/water, ethanol/water/ammonium carbonate or methanol/water/ammonium carbonate were spray dried using a laboratory spray dryer. Spray dried products were characterised by scanning electron microscopy, X-ray powder diffraction, differential scanning calorimetry, FTIR, laser diffraction particle sizing and density measurement. Nanoporous microparticles (NPMPs) were prepared from the alcoholic solutions containing ammonium carbonate. NPMPs were amorphous in nature, had median particles sizes less than 3 microm and densities that were significantly reduced compared to non-porous spray dried bendroflumethiazide powder. The novel process may be used to produce excipient-free amorphous microparticles with desirable physical properties such as amorphous solid state, porosity and low bulk density. This new engineering technology has applications in the design of other therapeutic agents such as those used in pulmonary delivery.
Subject(s)
Antihypertensive Agents/chemistry , Bendroflumethiazide/chemistry , Nanoparticles , Antihypertensive Agents/administration & dosage , Bendroflumethiazide/administration & dosage , Desiccation , Microscopy, Electron, Scanning , Nebulizers and Vaporizers , Particle Size , Powders , Spectroscopy, Fourier Transform Infrared , Surface-Active Agents , X-Ray DiffractionABSTRACT
Simplified and readily feasible techniques of double contrast examination of the colon, before and after surgery, are presented. The examination is easy to perform, well tolerated by patients, and has a high diagnostic yield. Methods, indications, and uses are discussed. Illustrative case material is shown.
