The potential of interpersonal communicative networks for message transfer from outside information sources : a study of two Missouri communities

Digitized 2007 AES.Includes bibliographical references (page 39)

Theory of nonlinear rheology and yielding of dense colloidal suspensions

A first principles approach to the nonlinear flow of dense suspensions is presented which captures shear thinning of colloidal fluids and dynamical yielding of colloidal glasses. The advection of density fluctuations plays a central role, suppressing the caging of particles and speeding up structural relaxation. A mode coupling approach is developed to explore these effects.Comment: 4 pages, 2 figures; slightly corrected version; Phys. Rev. Lett., to be published (2002

Pregabalin for the treatment of postoperative pain: Results from three controlled trials using different surgical models

Conclusion: There were no significant differences between pregabalin and placebo with respect to the primary pain intensity measure in each of the three clinical trials. These studies encompass a large dataset (1,233 patients in total), and their results should be considered when assessing pregabalin’s effectiveness in postoperative pain. Further studies are required to determine the potential pain-reducing benefit of pregabalin in the postoperative setting

The rheology of hard sphere suspensions at arbitrary volume fractions: An improved differential viscosity model

We propose a simple and general model accounting for the dependence of the viscosity of a hard sphere suspension at arbitrary volume fractions. The model constitutes a continuum-medium description based on a recursive-differential method that assumes a hierarchy of relaxation times. Geometrical information of the system is introduced through an effective volume fraction that approaches the usual filling fraction at low concentrations and becomes one at maximum packing. The agreement of our expression for the viscosity with experiments at low- and high-shear rates and in the high-frequency limit is remarkable for all volume fractions.Comment: 16 pages, 6 figures, submitte

Mechanistic Oral Absorption Modeling and Simulation for Formulation Development and Bioequivalence Evaluation: Report of an FDA Public Workshop

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138394/1/psp412204.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138394/2/psp412204_am.pd

A direct numerical simulation method for complex modulus of particle dispersions

We report an extension of the smoothed profile method (SPM)[Y. Nakayama, K. Kim, and R. Yamamoto, Eur. Phys. J. E {\bf 26}, 361(2008)], a direct numerical simulation method for calculating the complex modulus of the dispersion of particles, in which we introduce a temporally oscillatory external force into the system. The validity of the method was examined by evaluating the storage $G'(\omega)$ and loss $G"(\omega)$ moduli of a system composed of identical spherical particles dispersed in an incompressible Newtonian host fluid at volume fractions of $\Phi=0$, 0.41, and 0.51. The moduli were evaluated at several frequencies of shear flow; the shear flow used here has a zigzag profile, as is consistent with the usual periodic boundary conditions

Statistička analiza nanokapsuliranja niskomolekularnog heparina

The objective of this study was to use Box-Behnken design (BBD) to investigate the influence of formulation variables on the properties of heparin-loaded poly(lactic-co-glycolic acid) (PLGA)-Eudragit-RLPO (E-RLPO) nanoparticles (NP) in terms of mean diameter (as size) and drug encapsulation efficiency. The NPs were prepared by the double emulsion solvent evaporation method. The independent variables were: X1 olymer mass ratio (PLGA:E-RLPO) in the oil phase, X2 concentration of polyvinyl alcohol (PVA) as emulsion stabilizer, and X3 volume of the external aqueous phase (W2). Particle size (analyzed by dynamic light scattering) and encapsulation efficiency (EE, estimated by spectrophotometry) were the investigated responses. The polynomial equation obtained from regression analysis of the reduced model (p = 0.0002, F = 25.7952 and R2 = 0.96) provided an excellent fit. The optimal size for the NP was found to be 134.2 ± 16.5 nm with formulation variables of 48.2:61.8, 0.321 (%, m/V) and 263 mL for X1, X2 and X3, respectively. Probably, due to electrostatic interaction between the negatively charged drug and the positively charged E-RLPO, the percent EE of heparin was between 74.4 ± 6.5 % (lowest value) and 92.1 ± 5.3 % (highest value). The data suggest that BBD is a useful tool in rational design of heparin-loaded NPs.Box-Behnkenovo dizajniranje (BBD) primijenjeno je za praćenje utjecaja formulacijskih varijabli na svojstva nanočestica (NP) s heparinom. Za izradu nanočestica korišten je kopolimer mliječne i glikolne kiseline (PLGA) i Eudragit-RLPO (E-RLPO). Nanočestice su pripravljene metodom dvostruke evaporacije otapala iz emulzije. Nezavisne varijable bile su: X1 omjer masa polimera (PLGA : E-RLPO) u uljnoj fazi, X2 koncentracija polivinil alkohola (PVA) kao stabilizatora emulzije i X3 volumen vanjske vodene faze (W2). Zavisne varijable bile su veličina čestica (analizirana pomoću dinamičkog rasapa svjetlosti) i učinkovitost inkapsuliranja (EE) (praćena spektrofotometrijski). Polinomska jednadžba dobivena regresijskom analizom reduciranog modela odlično je odgovarala (p = 0,0002, F = 25,7952 i R2 = 0,96). Optimalna veličina nanočestica bila je 134,2 ± 16,5 nm s formulacijskim varijablama 48,2:61,8, 0,321 (%, m/V) i 263 mL for X1, X2 odnosno X3. Vjerojatno je zbog elektrostatskih interakcija između negativno nabijene ljekovite tvari i pozitivno nabijenog E-RLPO učinkovitost inkapsuliranja heparina varirala od 74,4 ± 6,5 % (najniža vrijednost) do 92,1 ± 5,3 % (najviša vrijednost). Rezultati sugeriraju da je BBD vrlo korisno u racionalnom dizajniranju nanočestica s heparinom

FDA Critical Path Initiatives: Opportunities for Generic Drug Development

FDA’s critical path initiative documents have focused on the challenges involved in the development of new drugs. Some of the focus areas identified apply equally to the production of generic drugs. However, there are scientific challenges unique to the development of generic drugs as well. In May 2007, FDA released a document “Critical Path Opportunities for Generic Drugs” that identified some of the specific challenges in the development of generic drugs. The key steps in generic product development are usually characterization of the reference product, design of a pharmaceutically equivalent and bioequivalent product, design of a consistent manufacturing process and conduct of the pivotal bioequivalence study. There are several areas of opportunity where scientific progress could accelerate the development and approval of generic products and expand the range of products for which generic versions are available, while maintaining high standards for quality, safety, and efficacy. These areas include the use of quality by design to develop bioequivalent products, more efficient bioequivalence methods for systemically acting drugs (expansion of BCS waivers, highly variable drugs), and development of new bioequivalence methods for locally acting drugs