Lukasz Hawelek

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Verapamil hydrochloride (VH) is a very popular calcium channel blocker. Solubility of its crystalline form in the blood reaches only 10-20%. Thus, it seems to be very important to improve its bioavailability. In this article, we show that the preparation of the amorphous form of VH enhance its dissolution rate. In addition we performed dielectric(More)
Antibiotics are chemical compounds of extremely important medical role. Their history can be traced back more than one hundred years. Despite the passing time and significant progress made in pharmacy and medicine, treatment of many bacterial infections without antibiotics would be completely impossible. This makes them particularly unique substances and(More)
To improve solubility of tadalafil (Td), a poorly soluble drug substance (3μg/ml) belonging to the II class of the Biopharmaceutical Classification System, its six different solid dispersions (1:1, w/w) in the following polymers: HPMC, MC, PVP, PVP-VA, Kollicoat IR and Soluplus were successfully produced by freeze-drying. Scanning electron microscopy showed(More)
To investigate the effect of cryogrinding on chemical stability of the diuretic agent furosemide and its mixtures with selected excipients. Furosemide was ground at liquid nitrogen temperature for 30, 60, 120 and 180 min. Mixtures of furosemide-PVP and furosemide-inulin (1:1) were milled under cryogenic conditions. Materials were analyzed by XRD, UPLC, MS(More)
Recently it was reported that upon mechanical milling of pure furosemide significant chemical degradation occurs (Adrjanowicz et al. Pharm. Res.2011, 28, 3220-3236). In this paper, we present a novel way of chemical stabilization amorphous furosemide against decomposing that occur during mechanical treatment by preparing binary mixtures with acylated(More)
Cryomilling was applied to obtain amorphous forms of the base ziprasidone and its hydrochloride salt. Complete amorphization of both samples was confirmed by differential scanning calorimetry and X-ray measurements. As it turned out, cryogrinding is very effective way to obtain these drugs in the amorphous state, especially because melting of both(More)
Glibenclamide (GCM) is an oral hypoglycemic agent of the sulfonylurea group used in the treatment of non-insulin-dependent diabetes. Crystalline GCM is characterized by low bioavailability, which is attributed to its poor dissolution properties. It prompted us to prepare this drug in its amorphous form as a means to enhance its dissolution characteristics.(More)
In this paper, we present a novel way of stabilization of amorphous celecoxib (CEL) against recrystallization by preparing binary amorphous celecoxib-octaacetylmaltose (CEL-acMAL) systems by quench-cooling of the molten phase. As far as we know this is the first application of carbohydrate derivatives with acetate groups to enhance the stability of an(More)
Broadband dielectric measurements were performed in a wide range of temperatures on glucose, maltose, and their acetyl derivatives. We have indicated that molecular dynamics above and below the glass transition temperature differ considerably for the hydrogen-bonded and van der Waals systems. We have shown that structural relaxation dispersions of D-glucose(More)
By using dielectric spectroscopy we analyzed the relation between molecular mobility and tendency of the amorphous celecoxib to recrystallize. We found that celecoxib is kinetically a fragile glassformer, contrary to the conclusion reached by others from thermodynamic fragility. The possible correlation of the large tendency of celecoxib to crystallize with(More)