Sci. Pharm., Volume 75, Issue 2 (June 2007) – 3 articles , Pages 55-96

It this work was studied the influence of polyols (propylene glycol, glycerol and sorbitol) on the physicochemical parameters (partition coefficient and surface tension) and liberation from aqueous solutions with propylene glycol of two derivatives of phenylcarbamic acid. Studied parameters and liberation were influenced by the structure of the studied derivatives and with the type and concentration of polyols. Full article

The aim of this work was to improve the dissolution rate of albendazole (ABZ) by preparing its microparticles with certain hydrophilic polymers such as hydroxypropyl methylcellulose (HPMC), polyvinyl alcohol (PVA), and polyvinyl pyrrolidone (PVP) using spray drying technique. Microparticles of ABZ with these polymers were prepared in different ratios of 1:1, 1:2, and 1:4 by spray drying technique. Morphology and characterization of the prepared ABZ microparticles was studied and photographed using a biological microscope and examined by scanning electron microscope. Smooth surface and spherical microparticles of ABZ were detected by these methods which indicating the coating of drug crystals by the studied polymers. Physicochemical properties of drug alone and its spray dried microparticles were investigated using differential scanning calorimetry (DSC) and powder X-ray diffractometry (PXRD). DSC and PXRD analysis showed that ABZ transformed from the crystalline state to amorphous state by spray drying with these polymers as confirmed by disappearance of its melting peak and characteristic crystalline peaks. Dissolution rate of ABZ from the prepared microparticles was determined and compared to its corresponding physical mixtures. Results have shown that the dissolution rate of ABZ has been enhanced extremely from its spray dried microparticles and reached 100 % as compared to the corresponding physical mixtures. This indicates the success of spray drying technique for improvement of ABZ dissolution. Moreover, it was found that the dissolution rate of the drug was affected by the polymer type and the ratio of ABZ to polymer. The highest dissolution of ABZ was obtained with HPMC in 1:1 ratio and with both PVA and PVP in ratio of 1: 4 microparticles. The transformation of ABZ from crystalline to amorphous state by spray drying and the hydrophilic coating of drug particles by the polymers are considered among the factors which contributed in improvement of ABZ dissolution. Full article

According to our previous study 29 derivatives of 2-hydroxy-3-(4-phenylpiperazin-1-yl)-propylphenylcarbamates were tested for in vitro antimycobacterial activity against potential pathogenic strains Mycobacterium kansasii and Mycobacterium avium. The variations in group of compounds were by the substitution on phenyl rings. The Free-Wilson method was used to evaluate structure-antimycobacterial activity relationships. The advantage of compounds under study is in the activity against M. kansasii. Full article