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Abstract  

Microencapsulation of Lippia sidoides essential oil was carried out by spray drying. Blends of maltodextrin and gum arabic were used as carrier. Spray dried microparticles were characterized using conventional (thermogravimetry, evolved gas analysis) and combined (thermogravimetry-mass spectrometry analysis) thermal analysis techniques in order to evaluate the abilities of carriers with different compositions in retaining and in releasing the core vs. dynamic heating. Thermal analysis was useful to evaluate the physico-chemical interactions between the core and carriers and to determine the protective effect of the carriers on the evaporation of essential oil.

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Abstract  

A study was made of the possibilities of gradually decreasing the concentration of the toxic organic solvent in the process of microsphere preparation. Ammonio methacrylate copolymer-based microspheres were prepared by spray drying or conventional solvent evaporation techniques, and compared. The formulations were designed by varying the preparation methods and the concentrations of four polar cosolvents as independent variables. DSC was used to study the relationship between the changes in the independent variables and three of the main thermal events of the microspheres. Raman spectroscopy was used to investigate and confirm the possible interactions between drug and copolymer. Appropriate choice of the independent variables led to the molecularly dispersed drug in the polymer matrix. It was demonstrated that only the nature of the preparation method caused significant variations in the structure and thermal behaviour of the microspheres.

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more popular, the reduction of vitamin D 3 in the diet rendered a nutritional concern [ 7 – 9 ]. The binding properties of β-LG make it a potential ingredient to deliver vitamin D 3 in a form of spray-dried complex with β-LG to fat free food systems

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is to report the compatibility of lamivudine with pharmaceutical excipients (spray dried lactose, polyvinyl pyrrolidine K-30, magnesium stearate and talc) and a novel synthesized cross-linked sago starch by DSC, ISS and FT

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Solid inclusion complexes of TolperisoneHCl with five various cyclodextrins were prepared by kneading and spray drying. The complex formation between the drug and the cyclodextrins were proven using thermoanalytical methods, X-ray diffraction, IR spectroscopy. The results of the solid state investigations were supported by the liquid phase investigations, such solubility and parition constant measurements and stability constant determination. Among all cyclodextrins used the β- and γ-CD-s were found to be the best complexing agents.

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Abstract  

The present investigation was carried out to screen compatibility of some diluents with pefloxacin mesilate using differential scanning calorimetry (DSC), isothermal stability studies, along with stability studies in liquid state and to assign relative ranking to diluents. Compatibility was predicted with MCC101, MCC102, DCP anhydrous, Emcompress, while melting endotherm of drug was lost in admixtures of dextrose anhydrous, Pearlitol, Lactopress spray dried, Lactochem fine powder and Lycatab indicating possibility of interaction. Enthalpy changes were used for relative ranking of diluents.

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Abstract  

Inclusion complexation between cyclodextrin derivatives (hydroxypropyl-β-cyclodextrin and methyl-β-cyclodextrin) and a very poorly water-soluble antifungal agent, ketoconazole, was studied. Solid products were prepared by physical mixing, kneading and spray-drying methods in four molecular ratios: 2:1, 1:1, 1:2 and 1:3. The possibility of complex formation between the drug and the cyclodextrins was studied by thermal analysis. Supplementary techniques, such as X-ray diffractometry and Fourier transformation-infrared spectroscopy, were also applied to interpret the results of the thermal study of the products.

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Abstract  

γ-Cyclodextrin and dimethyl-β-cyclodextrin were used as solubilizing agents for a very poorly water-soluble drug, an imidazole derivative antifungal agent, clotrimazole; with the aim of improving the physicochemical properties of the drug. Solid products were prepared by physical mixing, kneading, precipitation and spray-drying methods in 1:1 and 1:2 drug:cyclodextrin molar ratios. Drug interactions were studied by thermoanalytical methods such as DSC, DTA, TG and DTG, X-ray diffractometry and Fourier transformation-infrared spectroscopy. The results demonstrated the formation of inclusion complexes in some products.

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Summary Inclusion complexation between dimethyl-β-cyclodextrin and a very poorly water-soluble serum lipid-regulating agent, gemfibrozil, was studied. Products were prepared by several methods (physical mixing, kneading, spray-drying and ultrasonic treatment) in four different molecular ratios (2:1, 1:1, 1:2 and 1:3). The possibility of complex formation between the drug and the host molecule was studied by thermal analysis. Supplementary techniques, such as Fourier transformation-infrared spectroscopy and X-ray diffractometry, were also applied to interpret the results of thermal study of the products.

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Abstract  

The aim of this paper is to determine temperature and structural changes caused by tableting and to deduce from the combination of temperature measurement and the determination of structural changes whether temperature increase induced by tableting contributes to tablet quality. Tablets were produced of microcrystalline cellulose (MCC), spray-dried lactose, pregelatinized starch, and dicalcium phosphate dihydrate (DCPD) with an instrumented single punch tableting machine. The temperature pattern at the surface of the tablets was measured starting directly after tableting with an infrared thermoviewer and an infrared sensor. Powder and tablets were analyzed by FT-Raman spectroscopy, the tablets were analyzed directly after tableting and after one month of storage. The crushing force of the resulting tablets was determined. For all materials a temperature increase (TI) induced by tableting was determined with both methods used. The order of the temperature increase was the same for both methods used: TI (MCC)>TI (spray-dried lactose)>TI (pregelatinized starch)>TI (DCPD). The order was also identical for the crushing force of the tablets. The extent of differences in the spectra followed the same ranking. In conclusion, the temperature increase contributed to the changes in material structure and thus temperature increase is one factor which determined crushing force and thus tablet properties.

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