Co-Amorphous Formulations of Furosemide with Arginine and P-Glycoprotein Inhibitor Drugs

In this study, the amino acid arginine (ARG) and P-glycoprotein (P-gp) inhibitors verapamil hydrochloride (VER), piperine (PIP) and quercetin (QRT) were used as co-formers for co-amorphous mixtures of a Biopharmaceutics classification system (BCS) class IV drug, furosemide (FUR). FUR mixtures with VER, PIP and QRT were prepared by solvent evaporation, and mixtures with ARG were prepared by spray drying in 1:1 and 1:2 molar ratios. The solid-state properties of the mixtures were characterized with X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) in stability studies under different storage conditions. Simultaneous dissolution/permeation studies were conducted in side-by-side diffusion cells with a PAMPA (parallel artificial membrane permeability assay) membrane as a permeation barrier. It was observed with XRPD that ARG, VER and PIP formed co-amorphous mixtures with FUR at both molar ratios. DSC and FTIR revealed single glass transition values for the mixtures (except for FUR:VER 1:2), with the formation of intermolecular interactions between the components, especially salt formation between FUR and ARG. The co-amorphous mixtures were found to be stable for at least two months under an elevated temperature/humidity, except FUR:ARG 1:2, which was sensitive to humidity. The dissolution/permeation studies showed that only the co-amorphous FUR:ARG mixtures were able to enhance both the dissolution and permeation of FUR. Thus, it is concluded that formulating co-amorphous salts with ARG may be a promising option for poorly soluble/permeable FUR.

Yarn-reinforced hydrogel composite produced from woven fabrics by simultaneous dissolution and cross-linking

Polyvinyl alcohol (PVA)/cotton (Co) woven fabrics were produced by constructing Co as warp yarns and PVA as weft yarns in the fabric structure. As-prepared PVA/Co fabrics were treated with borax/water solution. Because of the simultaneous dissolution and gelation of PVA yarn in the fabric and transformation of PVA molecules into cross-linked gel structures, gel penetrated among the yarns in the matrix form and hence Co yarn-reinforced composite hydrogels were obtained. The retention time of water by composite hydrogels was first increased and then decreased by increasing borax concentration in the cross-linker solution. With yarn reinforcing, the tensile strength of hydrogel structure significantly increased. Mechanical properties of hydrogel composites were very variable depending on water content in the structure and tensile strength tremendously increased when water evaporated from the structure. Thermal and chemical characterizations of yarn-reinforced hydrogel composites were conducted in addition to swelling and mechanical analysis to investigate the performance of the hydrogel composites.

Water Cartographies of Goa: Khazans, Sedimentation and Dissolution of Coastal Cultural Landscapes

Goa’s landscape is an encounter between dry and wet materialities, the Indian Ocean world and the Western Ghats of Konkan, the distant and the localized, open seas and deep currents and floodplains, estuaries and muddy soils. Reordered in geometric geographies, these curvilineous cultivated lowlands, named khazans, surrounded by villages, temples and churches are part of the landscape and crucial sensorial layers of this Indian state. Village neighbourhoods (named waddi in Konkani) are organized not around a solid centre, but along several interconnected paddy fields, creating particular territorial maps of each village. Can our perception change, thus, if we see the Goan territory having water as its defining element, instead of a land-based perspective, and consider these lands as cultural landscapes? The aesthetic and heritage dimensions of cultural landscapes are essential to perceive Goa as a place of simultaneous dissolution and sedimentation along time and cultural geographies. Based on recent research on Goa and the Indian Ocean, this text proposes khazans to be recognized both as natural elements and cultural signifiers and as the main cartographic layers of inclusive Goan cultural landscapes.