Abstract. Wet coating methods use organic solvents to prepare layered particles that provide controlledrelease medications. However, this approach has disadvantages in that it can cause particle agglomeration, reduce pharmaceutical stability, and leave residual organic solvents. We used a dry coating method to overcome these issues. Fine particles (less than 50 μm in diameter) of controlled-release theophylline were created using theophylline (TP; model drug), polyethylene glycol 20,000 (PEG; drug fixative), hydrogenated castor oil (HCO; controlled-release material), hydrogenated rapeseed oil (HRSO; controlledrelease material), and cornstarch (CS; core particle). An ultrahigh-speed mixer was employed to mix TP and CS for 5 min at 28,000 rpm. Subsequent addition of PEG produced single-core particles with a drug reservoir coating. Addition of HCO and HRSO to these particles produced a controlled-release layer on their surface, resulting in less than 10% TP dissolution after 8 h. We successfully demonstrated that this dry coating method could be used to coat 16-μm CS particles with a drug reservoir layer and a controlledrelease layer, producing multi-layer coated single-core particles that were less than 50 μm in diameter. These can be used to prepare controlled-release tablets, capsules, and orally disintegrating tablets.
The angiographic findings of Takayasu's arteritis in a series of 113 patients were reviewed. Predominant findings were stenotic or occlusive changes, but fusiform or saccular aneurysms were also found in 36 patients (31.9%) in the various sites of aorta and its major branches. Multiple aneurysms were found in 15 patients. The most common site of aneurysms was the ascending aorta (16 patients); in 7 of the patients these were complicated by aortic regurgitation. Aneurysms developed in the aortic arch in 3 patients, in the descending aorta in 11, in the abdominal aorta in 7, and in the major branches of the aortic arch in 9 patients. In 2 patients, follow-up angiograms showed enlargement of the aneurysms, and rupture of the aneurysm occurred in 1 patient. Aneurysms were found even in young patients. A fifteen-year-old female showed a huge aneurysm in the ascending aorta as the initial manifestation of this disease. Thickening of the walls of aneurysms was common and characteristic. This study revealed the moderately high incidence of aneurysms of various sites of arteries in patients with Takayasu's arteritis. The authors conclude that aneurysm, as well as occlusive changes, can be a primary lesion.
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