Investigation of Deteriorated Dissolution of Amorphous Itraconazole: Description of Incompatibility with Magnesium Stearate and Possible Solutions

Disadvantageous crystallization phenomenon of amorphous itraconazole (ITR) occurring in the course of dissolution process was investigated in this work. A perfectly amorphous form (solid dispersion) of the drug was generated by the electroblowing method (with vinylpyrrolidone-vinyl acetate copolymer), and the obtained fibers were formulated into tablets. Incomplete dissolution of the tablets was noticed under the circumstances of the standard dissolution test, after which a precipitated material could be filtered. The filtrate consisted of ITR and stearic acid since no magnesium content was detectable in it. In parallel with dissolution, ITR forms an insoluble associate, stabilized by hydrogen bonding, with stearic acid deriving from magnesium stearate. This is why dissolution curves do not have the plateaus at 100%. Two ways are viable to tackle this issue: change the lubricant (with sodium stearyl fumarate >95% dissolution can be accomplished) or alter the polymer in the solid dispersion to a type being able to form hydrogen bonds with ITR (e.g., hydroxypropyl methylcellulose). This work draws attention to one possible phenomenon that can lead to a deterioration of originally good dissolution of an amorphous solid dispersion.

Intraluminal chondrosarcoma leading to occlusion of the brachiocephalic trunk

A 62-year-old female patient was admitted with temporary neurological symptoms. CT scan revealed occlusion of the brachiocephalic trunk by an intraluminal mass suspicious for a thrombus and extending into the ascending aorta. The patient underwent aortic arch replacement with reinsertion of the supraaortic vessels. A 5 × 3 × 4 cm large mass was found in the aorta which had obviously caused occlusion of the brachiocephalic trunk. The patient had an uneventful postoperative recovery and follow-up imaging showed no pathological findings. Histopathological examination revealed inhomogeneous chondroid tissue such as that found in a G2 grade bone chondrosarcoma.

Atrial extracellular matrix remodelling in patients with atrial fibrillation

Atrial fibrillation (AF) is the most frequent clinical arrhythmia. Atrial fibrosis is an important factor in initiating and maintaining AF. However, the collagen turnover and its regulation in AF has not been completely elucidated. We tested the hypothesis that the extracellular matrix changes are more severe in patients with permanent AF in comparison with those in patients in sinus rhythm (SR). Intraoperative biopsies from the right atrial appendages (RAA) and free walls (RFW) from 24 patients with AF undergoing a mini-Maze procedure and 24 patients in SR were investigated with qualitative and quantitative immunofluorescent and Western blot analyses. As compared with SR, all patients with AF exhibited dysregulations in collagen type I and type III synthesis/degradation. Tissue inhibitors of metalloproteinases (TIMP2) was significantly enhanced only in RAA-AF. As compared with SR, collagen VI, matrix metalloproteinases MMP2, MMP9 and TIMP1 were significantly increased while TIMP3 and TIMP4 remained unchanged in all AF groups. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a newly discovered MMPs inhibitor, was elevated in RFW as compared to RAA-AF (P<0.05) and RFW-SR (P<0.05). The level of transforming growth factor (TGF)-β1 was higher in AF than SR. Smad2 and phosphorylated Smad2 showed an elevation in RFW-AF as compared to RFW-SR, RAA-AF, and RAA-SR groups (P<0.05). Conclusions: Atrial fibrosis in AF is characterized by severe alterations in collagen I and III synthesis/degradation associated with disturbed MMP/TIMP systems and increased levels of RECK. TGF-β1 contributes to atrial fibrosis via TGF-β1-Smad pathway by phospho-rylating Smad2. These processes culminate in accumulations of fibrillar and non-fibrillar collagens leading to excessive atrial fibrosis and maintainance of AF.

Trapidil decreases the aggregation of platelets from heart transplant recipients ex vivo

Heart transplant recipients show platelet hyperaggregability, which may be related to the incidence of graft vasculopathy. We investigated whether trapidil can inhibit the aggregation of platelets from these patients. Platelet count, mean platelet volume (MPV), and adenosine diphosphate (ADP)-induced platelet aggregation were determined in 18 heart transplant recipients and 12 healthy subjects. Additionally, platelet-rich plasma from the patients was incubated with trapidil or with saline, prior to measuring ADP-induced aggregation. The MPV was significantly greater in patients compared to controls (9.4+/-1.1 vs 8.5+/-0.7 fL; P=.01), and ADP-induced platelet aggregation was significantly increased in patients compared to controls (81.2%+/-13.1% vs 69.6%+/-16.2%; P=.04, respectively). The trapidil-treated samples showed significantly decreased platelet aggregation compared to the control samples (24.2%+/-12.6% vs 66.7%+/-11.7%; P<.001). Platelets from heart transplant recipients showed an increased MPV and increased ADP-induced aggregation. Trapidil effectively reduced the ADP-induced aggregation ex vivo.

Non-Aneurysmal Inflammation of the Aorta in Combination with Aortic Valve Disease

A 61-year-old man presented with aortic valve stenosis, coronary artery disease in combination with rheumatic arthritis, peri-aortic inflammation and fibrosis with aortitis. In the pathological literature this has been termed chronic periaortitis, while in the surgical literature, non-aneurysmal dilatation of the aorta associated with atherosclerosis and inflammation has been described as aortitis. The name chronic periarteritis refers to the associated involvement of coronary arteries. Although different terminologies have been used, it is suggested that all of them most likely represent the same disease entity.

Pre- and postoperative assessment of left ventricular function by magnetic resonance imaging and 2-D-echocardiography in patients undergoing left ventricular aneurysmectomy

BACKGROUND

Left ventricular (LV) aneurysms may complicate myocardial infarctions. Reliable quantification of LV functional parameters is mandatory to predict clinical outcome in patients undergoing LV aneurysmectomy. We compared global LV function measured by magnetic resonance (MR) and 2-D-echocardiography in patients before and after aneurysmectomy.

METHODS

31 patients (23 male), mean age 64 (range 35 - 85) years with an LV aneurysm (25/31 anterior MI, 5/31 inferior MI, 1/31 both) were enrolled. MR and echocardiography were performed directly before and 3 - 65 (median 8) days after surgery. MR studies were performed on a 1.5 Tesla scanner. End-diastolic and end-systolic volumes and diameters (EDV/ESV, EDD/ESD), ejection fraction (EF) and stroke volume (SV) were determined. Echocardiography was performed to determine EF, EDD and ESD. NYHA class was assessed before and 3 months after surgery.

RESULTS

After aneurysmectomy MR analysis showed a decrease in EDV (255 +/- 68 ml to 202 +/- 59 ml) ( p < 0.001) and ESV (186 +/- 71 ml to 134 +/- 53 ml; p < 0.001); EF increased (28 +/- 10 % to 35 +/- 12 %; p < 0.001); EDD/ESD decreased ( p < 0.01). Compared to echocardiography, a low correlation was found in EF before/after surgery r = 0.76/r = 0.69 and ESD r = 0.43/r = 0.60, respectively. In EDD a good correlation was found before surgery (r = 0.81), and a lower correlation after surgery (r = 0.72). NYHA class improved from 3.0 +/- 0.5 before to 1.8 +/- 0.8 after operation ( p < 0.001).

CONCLUSION

Resection of an LV aneurysm results in a mean improvement of 25 % in LV function, and improved clinical outcome. In asymmetric ventricles with aneurysms MR proved to be superior as a sensitive and non-invasive tool compared to conventional 2-D-echocardiography.