Characterization of Canadian biomass for alternative renewable biofuel

Biomass represents the renewable energy source and their use reduces the consumption of fossil fuels and limits the emission of CO₂, SO_x, NO_x and heavy metals. They are used in pyrolysis, gasification, combustion and co-combustion. Present study aims to highlight the common biomass available in Canada such as wheat straw, barley straw, flax straw, timothy grass and pinewood. The biomass samples were collected form Saskatoon, Canada and examined for their physical and chemical characteristics using static bomb calorimeter, XRD, TGA, ICP-MS, CHNSO, FT-IR and FT-NIR. The biomass samples were subjected to three-step extraction process, i.e. hexane, alcohol and water extraction separately, after extraction the raffinate biomass was acid hydrolyzed. The acid soluble fractions, which mainly contained degraded sugars, were analysed by HPLC and the lignin content was determined using acid insoluble fraction. The hexane extract (i.e. waxes), alcohol extract and lignin were characterized by FT-IR spectroscopy. Among all the biomass samples pinewood shows lower ash and lignin content, while shows higher calorific value, cellulose and hemicellulose content. The appreciable amount of hexane soluble in pinewood was due to the presence of terpene hydrocarbons. However among the agricultural biomass samples barley straw shows higher ash, wax and lignin content compared to wheat and flax straw. All these properties combined together have shown that pinewood, wheat and flax can act as the potential candidates for bio-energy production.     

Current perspectives of solubilization: potential for improved bioavailability

This review focuses on the recent techniques of solubilization for the attainment of effective absorption and improved bioavailability. Solubilization may be affected due to cosolvent water interaction or altered crystal structure by cosolvent addition. Micellar solubilization could be affected by both ionic strength and pH. Addition of cosolvents to the surfactant solutions offers only a small advantage because of the decrease in the solublization capacity of the micelles. Polymorphism is known to influence dissolution and bioavailability of the drugs. Molecular modeling study of cyclodextrin inclusion complexations can predict the inclusion modes, stoichiometry of the complex, and the relative complexing efficiency of cyclodextrins with various drug molecules.     

Physicochemical characterization of interaction of ibuprofen by solid-state milling with aluminum hydroxide

This present study is a preliminary exploration of the affinity between a carboxylic model drug ibuprofen and aluminum hydroxide. Ibuprofen was comilled with aluminum hydroxide in different weight ratios in the solid state and was characterized by scanning electron microscopy (SEM), X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and in vitro dissolution studies. XRD and SEM studies indicated complete interaction of ibuprofen with aluminum hydroxide and complete amorphization of aluminum hydroxide-ibuprofen complexed salt as well, on comilling with aluminum hydroxide at 1:2 ratio. FTIR data showed the disappearance of acid carbonyl peak with the appearance and the corresponding increase in absorbance of new signal at 1,682 cm(-1) in the 1:1 and 1:2 ibuprofen-aluminum hydroxide-comilled powder. The accompanied increase in the absorbance of carboxylate peak in the ibuprofen-aluminum hydroxide physical mixture, and 1:0.1, 1:0.5, 1:1, and 1:2 (IBA(pm), and IB(1)A(0.1), IB(1)A(0.5), IB(1)A(1), and IB(1)A(2), respectively) comilled powder indicated an acid-base reaction between ibuprofen and aluminum hydroxide. On storage at 40 degrees C and 75% relative humidity (RH) for 10 weeks, XRD study showed the absence of reversion to the crystalline state and FTIR data revealed continued increase of new signal at 1,682 cm(-1) relative to carboxylic acid peak and no reappearance of carboxylic acid peak. In vitro dissolution studies revealed that the percent release of ibuprofen from the aluminum hydroxide-comilled powder is in the following order: IB(1)A(2) < IB(1)A(1) < ibuprofen crystal < ibuprofen milled alone < IB(1)A(0.1) < IB(1)A(0.5). Aluminum metal cation might have interacted to form a complex through the carboxyl and carbonyl groups of ibuprofen. Improved dissolution of drug associated with IB(1)A(0.1) and IB(1)A(0.5) is because of the absence of a new signal at 1,682 cm(-1) and improved amorphization of the drug to some extent. Dissolution of drug affected in IB(1)A(2) and IB(1)A(1) may be because of the insoluble stable complex formation.