Compressibiliy and compactibility of pectin powders -A study of their potential as direct compression excipients in tablets

Papers 2 and 3 of this thesis are not available in Munin: 2. Salbu, L., Bauer-Brandl, A., Alderborn, G. and Tho, I.: 'Effect of degree of methoxylation and particle size on compression properties and compactibilty of pectin powders', Pharmaceutical Development and Technology (2011) 1–11. Available at http://dx.doi.org/10.3109/10837450.2010.535831 3. Salbu, L., Picker-Freyer, K. M., Schmid, W., Bauer- Brandl, A. and Tho, I.: 'Is one tablet sufficient? : Application of 3-D modelling to the compression of pectin powders' (manuscript)Pektinpulver med ulike prosentar metoksylering vart komprimert i ein komprimeringssimulator. Dette er ei avansert tablettmaskin som svært nøyaktig måler distansen tablettstempelet har gått (på mikrometernivå) og kor stor kraft som er involvert under komprimeringa (samantrykkinga av pulveret). Pektin med metoksyleringsgrad under 10% (også kalla pektinsyrer) gav dei mekanisk sterkaste tablettane, og er såleis den pektintypen det bør fokuserast på i framtidige forsøk med pektin som eit tabletthjelpestoff. Høgmetoksylert pektin, dvs. meir enn 50% metoksylering, var ueigna i tablttering ettersom dei ikkje gav samanhengande tablettar. Hovudsakleg skjedde det ein elastisk deformasjon med pektinpartiklane, og sidan dette generelt er ugunstig med hensyn på binding og mekanisk sterke tablettar vart det undersøkt kva mekanismar som bidreg til at tablettane heng saman. Det vart funne at ei viss grad av fragmentering skjedde i pektinsyrene. Plastisk deformasjon var det lite av. Avhandlinga viser at pektinsyrene og til dels andre pektintypar med metoksylering mindre enn eller lik 40% er veleigna som eit tabletthjelpestoff som kan fungere som ein bærar av ein aktiv substans til tjukktarmen.This thesis is dedicated to direct compression studies of pectin, a natural polysaccharide with potential as a pharmaceutical excipient due to its ability to act as a carrier for colon-specific drug delivery as well as for sustained drug release purposes. The main objective of this thesis was to study the suitability of pectin as a matrix former in tablets. The compressibility and compactibility of pectin powders were studied as a function of various degree of methoxylation (DM) grades and different particle sizes. Pectin powders with similar powder characteristics were compressed by direct compression on a compaction simulator and an instrumented tablet press, respectively. The results showed that pectin powders, irrespective of DM and particle size, were classified as class IIA powders, showing a low degree of particle rearrangement and a relatively low degree of fragmentation. The powders were relatively soft and resembled the deformation behaviour of pregelatinized starch, an elastically deforming material. The pectinic acids (DM ≤ 10%) were slightly more viscoelastic than the other pectin grades. However, in general terms, it should be emphasized that the DM had a limited effect on the compression behaviour (i.e. compressibility) although an increased DM gave slightly softer and slightly less brittle particles. On the contrary, the compactibility was strongly dependent on both DM and initial particle size. The low-methoxylated (LM) pectin (DM < 50%) and especially pectinic acids (DM ≤ 10%) produced mechanically strong tablets, whereas the high-methoxylated (HM) pectins did not produce coherent tablets. The tensile strength increased with decreasing initial particle size. Pectin also proved to have a high dilution potential as a binder/matrix former, as coherent tablets were produced even when 70% of an inert material was incorporated. To summarize, the results showed that pectins with DM ≤ 40% have potential as direct compression excipients in tablets

The European Union Data Privacy Directive and International Relations

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Tipper Credibility, Noninformational Tippee Trading, and Abstention from Trading: An Analysis of Gaps in the Insider Trading Laws

The regulation of insider trading in the United States prohibits only a fraction of the kind of behaviors which the Securities and Exchange Commission sought to curb in the 1930s. This Article explains the problems created by trading on tipper credibility and noninformation, as well as the difficulties associated with insider abstention from trading. These practices are conceptually akin to trading on inside information, yet they fall beyond the purview of existing prohibitions. The Article examines potential vehicles for rendering the regulations more consistent, including authorization of all insider trading, policing of information, the creation of inferences of fraud from circumstantial evidence, the prohibition of entire classes of trades, and the application of a reduced threshold fraudulent scheme concept to trigger liability in loophole cases

Transnational Bribery: The Big Questions

During the past few years, I have written extensively on the subject of transnational bribery. My articles have examined several aspects of this serious problem,\u27 including the Foreign Corrupt Practices Act ( FCPA ), 2 re-cent multilateral global conventions to fight bribery,3 and the comparative costs and benefits of legislative versus systemic or institutional forms of change.4 This body of work also has addressed some of the problems that can accompany aggressive legal remedies, such as potential cultural imperialism5 and global discord.6 This examination has been rewarding, and it has spurred a rich exchange with a number of very talented scholars, as the late 1990s has seen a renewed interest in legal research on the subjects of bribery and corruption. Yet detailed legal scholarship, like all highly specialized academic work, can leave us eager for more of the big picture. This Perspective reflects my own desire to take a step back from the issues I have addressed to date, and ask a basic question that may help frame some legal scholarship on bribery and corruption in the future: what are the big questions that we should be addressing in regard to these challenges as we enter the 21st century

AIDS and Drug Pricing: In Search of a Policy

This Article presents a comprehensive analysis of the policy considerations regarding the pricing of new AIDS drugs. Part I discusses the two countervailing interests that dominate the debate: the effect of patent monopoly policy on the speed and extent of research and development initiatives and the effect of monopoly pricing on drug accessibility. Part II addresses legal, economic, and ethical concerns that are crucial to the formulation of a sound drug pricing policy, including the principles of monopoly theory, the relationship between monopoly and regulation, the proper allocation of price concessions that reduce profits from normal monopoly levels, and the determination of how much profit is necessary to optimize research and development efforts. Part III examines a negotiated drug pricing proposal, aimed at creating and maintaining a fair, effective, and efficient response to the AIDS crisis. Part IV contains concluding remarks and suggests further areas of research and inquiry helpful to the thoughtful resolution of the public policy challenges raised herein