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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Compression analysis as a tool for technical characterization and classification of pharmaceutical powders

Nordström, Josefina January 2008 (has links)
<p>There are today strong incentives for an increased understanding of material properties and manufacturing processes to facilitate the development of new technologies in the pharmaceutical industry. The purpose of this thesis was to suggest methods requiring a low sample amount for characterization of technical properties of powders.</p><p>Compression analysis was used to evaluate the formulation relevance of some compression equations. Using the mechanics of single granules to estimate powder functionality was part of this work. It was concluded that the formability of granular solids and the plasticity of single granules could be determined with compression analysis by using the Kawakita model for single components and binary mixtures of ductile granules.</p><p>Further on, the fragmentation propensity of solid particles could be estimated from compression analysis by using the Shapiro equation, enabling indicators of both the fragmentation and the deformation propensity of particles to be derived in one single compression test.</p><p>The interpretations of the compression parameters were only valid if the influence of particle rearrangement was negligible for the overall compression profile. An index indicating the extent of particle rearrangement was developed and a classification system of powders into groups dependent on the incidence of particle rearrangement was suggested as tools to enable rational interpretations of compression parameters.</p><p>The application of compression analysis was demonstrated by investigating the relevance of the mechanics of granular solids for their tableting abilities. The plasticity of single gran-ules was suggested to influence both the rate of compactibility and the mode of deformation, and consequently the maximal tablet strength. The degree of granule bed deformation was shown to be a potential in line process indicator to describe the tableting forming ability.</p><p>This thesis contributes to a scheme, suitable in formulation work and process control, to describe manufacturability of powders for an enhanced tablet formulation technology.</p>
2

Compression analysis as a tool for technical characterization and classification of pharmaceutical powders

Nordström, Josefina January 2008 (has links)
There are today strong incentives for an increased understanding of material properties and manufacturing processes to facilitate the development of new technologies in the pharmaceutical industry. The purpose of this thesis was to suggest methods requiring a low sample amount for characterization of technical properties of powders. Compression analysis was used to evaluate the formulation relevance of some compression equations. Using the mechanics of single granules to estimate powder functionality was part of this work. It was concluded that the formability of granular solids and the plasticity of single granules could be determined with compression analysis by using the Kawakita model for single components and binary mixtures of ductile granules. Further on, the fragmentation propensity of solid particles could be estimated from compression analysis by using the Shapiro equation, enabling indicators of both the fragmentation and the deformation propensity of particles to be derived in one single compression test. The interpretations of the compression parameters were only valid if the influence of particle rearrangement was negligible for the overall compression profile. An index indicating the extent of particle rearrangement was developed and a classification system of powders into groups dependent on the incidence of particle rearrangement was suggested as tools to enable rational interpretations of compression parameters. The application of compression analysis was demonstrated by investigating the relevance of the mechanics of granular solids for their tableting abilities. The plasticity of single gran-ules was suggested to influence both the rate of compactibility and the mode of deformation, and consequently the maximal tablet strength. The degree of granule bed deformation was shown to be a potential in line process indicator to describe the tableting forming ability. This thesis contributes to a scheme, suitable in formulation work and process control, to describe manufacturability of powders for an enhanced tablet formulation technology.
3

Prediktion av hållfasthet för tabletter tillverkade av binära pulver av Kalciumfosfat dihydrat, Kollidon 30 och Kollidon 90F baserat på två komprimeringsparametrar samt en referenshållfasthet

Ahmad, Lana January 2024 (has links)
Draghållfasthet är motståndskraft mot brott då en kraft appliceras på tabletten. Förhållandet mellan applicerat kompakteringstryck och draghållfasthet kallas för draghållfasthet-tryckförhållande, SPR, som bestämmas experimentellt. Det är till nytta att utveckla en metod för prediktion av detta förhållande för att spara både material och tid inom industrin då tabletter är den vanligaste beredningsformen. I tidigare studie har en hybridmetod presenterats för att prediktera SPR för sex olika pulver med tillfredställande resultat. Syftet med denna studie var att testa samma metod för binära pulver. Då bestämdes experimentellt SPR baserat på 11 till 16 tryck. Resultat jämfördes med SPRpred baserat på komprimeringsparametrar Kawakita och Heckel, en referensdraghållfasthet samt två olika värden för proportionalitetsfaktorn α. Kalciumsulfat, kollidon 30 och kollidon 90F användes som enkomponentspulver, binära pulver med varierad andel bindemedel användes för utvärdering av betydelsen av bindemedlets sort och andel för tablettbildande förmåga. En draghållfasthetsplatå kunde erhållas endast för kollidon 30, kollidon 90F och 20% kollidon 30. Resultaten från SPRpred stämde överens för kollidon 90F och 20% kollidon 30, medans det delvis stämde för kollidon 30 där α = 4,1, vilket stärker metodens tillförlitlighet. Slutsatsen är också att ökad andel bindemedel ger en förbättring i tablettbildande förmåga.

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