Preparation and in vitro Characterization of Porous Carrier–Based Glipizide Floating Microspheres for Gastric Delivery

Floating microspheres have been utilized to obtain prolonged and uniform release of drug in the stomach for development of once-daily formulations. A controlled-release system designed to increase residence time in the stomach without contact with the mucosa was achieved through the preparation of floating microspheres by the emulsion solvent diffusion technique, using (i) calcium silicate (CS) as porous carrier; (ii) glipizide, an oral hypoglycemic agent; and (iii) Eudragit® S as polymer. The effects of various formulations and process variables on the internal and external particle morphology, micromeritic properties, in vitro floating behavior, drug loading, and in vitro drug release were studied. The microspheres were found to be regular in shape and highly porous. The prepared microspheres exhibited prolonged drug release (~8 h) and remained buoyant for >10 h. The mean particle size increased and the drug release rate decreased at higher polymer concentrations. No significant effect of the stirring rate during preparation on drug release was observed. In vitro studies demonstrated diffusion-controlled drug release from the microspheres. Microsphere formulation CS4, containing 200 mg calcium silicate, showed the best floating ability (88% buoyancy) in simulated gastric fluid. The release pattern of glipizide in simulated gastric fluid from all floating microspheres followed the Higuchi matrix model and the Peppas-Korsmeyer model

Music as artisan tradition

This paper attempts to explain three widely-held 'stylised facts' about the recent history of north Indian classical music. First, in the precolonial period, music and musicians were patronised by the courts. Second, from the early colonial period patronage declined and music tended to be commercialised. And third, in the process, accumulated knowledge and the quality of crafts manship decayed. In a received view in music scholarship, the transition from patronage to market involved an institutional change and a diffusion of teaching from 'family' to out siders. Decay is attributed to the consequent reluctance of masters to teach well. The paper disputes this view. It suggests that the decay can be seen as an imperfect adaptation by individuals to the changing economic environment, and that this is a more general phenomenon than music scholarship believes. On the other hand, in the instructional system, which was primarily apprenticeship, there was substantial continuity. In this interpretation, music history can be seen to belong to a larger history of north Indian craftsmanship. The paper illustrates this proposition by drawing on the experiences of other skilled urban crafts

New Horizons: Scalar and Vector Ultralight Dark Matter

The last decade has seen unprecedented effort in dark matter model building at all mass scales coupled with the design of numerous new detection strategies. Transformative advances in quantum technologies have led to a plethora of new high-precision quantum sensors and dark matter detection strategies for ultralight ($<10\,$eV) bosonic dark matter that can be described by an oscillating classical, largely coherent field. This white paper focuses on searches for wavelike scalar and vector dark matter candidates.The last decade has seen unprecedented effort in dark matter model building at all mass scales coupled with the design of numerous new detection strategies. Transformative advances in quantum technologies have led to a plethora of new high-precision quantum sensors and dark matter detection strategies for ultralight ($<10\,$eV) bosonic dark matter that can be described by an oscillating classical, largely coherent field. This white paper focuses on searches for wavelike scalar and vector dark matter candidates