Fabrication of terazocin-loaded poly(D,L-lactide) microspheres by an ultrasonic spray drying method and their release behaviors.

Terazocin should be frequently administered for a long period time for the treatment of benign prostatic hyperplasia which is one of the most common diseases in elderly men. Controlled delivery of terazocin using polymer microspheres has a great potential to solve the problem. In this study, terazocin-incorporated poly(D,L-lactide) (PDLLA) microspheres were fabricated by a novel ultrasonic spray drying (USD) method, which is a rapid one-step process. The approximate diameters of microspheres were in a range of between 0.3 and 3 microm. SEM confirmed that the microspheres had a spherical shape and narrow size distribution. FT-IR spectroscopy demonstrated that the incorporated terazocin remained intact after the USD process. The microspheres showed a fast initial burst release of terazocin within nine hours, followed by a slow but steady release for 49 days, suggesting that these microspheres are highly promising for controlled drug delivery.

Effects of Different Salts on Salt-Assisted Ultrasonic Spray Pyrolysis (SA-USP) Calcination for the Synthesis of Strontium Ferrite.

Strontium ferrite (hexaferrite), SrFe12O19, was successfully fabricated in sizes ranging from hundreds of nanometers to several micrometers by salt-assisted ultrasonic spray pyrolysis-calcination using different salt media. All samples were single phases of SrFe12O19 without the intermediate phase, α-Fe2O3, and their morphology was hexagonal. As calcination temperature increased, the size of as-calcined samples and saturation magnetization, Ms, increased while coercivity decreased. The particle size of the obtained nanoparticles varied depending on the salt media and calcination temperatures. The best magnetic properties obtained in this experiment were a coercivity of 6973 Oe with a saturation magnetization of 68.3 emu/g. To the best of our knowledge, these coercivity values are the highest ever obtained. We propose a detailed mechanism explaining the growth of these particles and conclude that the resulting single-domain particle size is about 70 nm, taking into account of factors affecting coercivity in ferrite nano- to micro-sized particles.