34 research outputs found
Granule Characterization During Fluid Bed Drying by Development of a Near Infrared Method to Determine Water Content and Median Granule Size
Prediction of quality attributes of continuously produced granules using complementary pat tools
Near infrared and Raman spectroscopy for the in-process monitoring of pharmaceutical production processes
Women storying HIV/AIDS in community
The research is about African women living with HIV and women
grieving the death of loved ones as a result of AIDS. We discuss
the women's preferred care for the ill person and for the family as
well as for the bereaved family. We consider together the effects
of HIV/AIDS in the community: the stigma attached to the disease
and the fears of people that they may contract HIV. The women
and I acknowledge the closely woven relationships between faith
and culture in a predominantly Xhosa community.
Participatory action research is used and contextual feminist
theology within a postmodern social construction approach to
narrative pastoral therapy.Philosophy, Practical and Systematic TheologyM.Th. (Practical Theology
Process understanding on high shear granulated lactose agglomerates during and after drying
In 2001 the FDA launched the Process Analytical Technology initiative as a response to the growing public and industrial awareness that there is a lack of process understanding required to have an optimal control of pharmaceutical manufacturing. The current research project was initiated based upon the insight that critical process and product attributes can only be acknowledged upon a thorough process understanding. This thesis can be seen as a follow up on earlier research done on wet high shear granulation; key process parameters that are involved in the wet high shear granulation process, including granule breakage and growth were determined. Although the relevance of these critical process parameters towards the formation of inhomogeneous granules was reported extensively, the consequences of the described in-homogeneity phenomena in granules in further processing were not elaborated. After the wet granulation process, a drying step is always necessary to obtain a basis for the final drug product. After the wet granulation process, a drying step is always necessary to obtain a basis for the final drug product but the drying of wet granules often involves an unwanted and uncontrolled size reduction. The aim of this thesis was to investigate the behavior of the granules throughout the drying process and the consequences of granule heterogeneity during and after the drying process. In this thesis it was shown that granular composition, size heterogeneity and water content are the critical process and product quality parameters during drying. Granule characterization revealed that the change in granule size of (partially) dried granules follows a three phase system characterized by a growth, plateau and breakage phase. The growth phase is based upon available surface water enabling layering growth and coalescence upon consolidation. Below a minimum liquid bridge volume the presence of very small amounts of water or the formation of solid bridges cannot prevent abundant size reduction. In the plateau phase above minimum water content, behavior of granules can be described with Rumpfsâ dynamic granule strength. More specific, in fluid bed drying the granular bed, the granule size, the inter-granular composition and water content are totally heterogeneous throughout the drying process. This heterogeneity differentiates the drying rate and extent of size increase and reduction of the different granule size classes in relation to the dynamic granule strength. Near infrared spectroscopy (NIR) is shown to be a versatile method to further determine the critical process and product factors by in-line monitoring of water content of granule and monitoring of granule size and attrition effects. By NIR it was shown that different drying parameters led to significantly different compositions of granules (non-crystalline and crystalline lactose) with a direct influence on the functionality of the granules such as compactibility. Finally, based upon the granule composition specific degradation of a steroid in lactose granules it is concluded that the heterogeneous composition of high shear granulated lactose granules dictates both the critical chemical and physical stability and quality aspects of the granules
The consequences of granulate heterogeneity towards breakage and attrition upon fluid-bed drying
High-shear granulated lactose granulates were dried in it fluid-bed dryer at various conditions. Granules were characterized by water content and size analysis. It is shown that the drying process is very dynamic in terms of growth and breakage phenomena. Granular size heterogeneity, composition and water content determine the granule behavior upon drying. Large granules consist of small primary particles and contain more water than small granules that consist of large primary particles. This differentiates the drying rate and extent of size reduction of the different granule size classes. The results enable it critical evaluation of process control and process monitoring. Understanding of granule behavior and continuous monitoring Of the fluid-bed drying process enables process and product optimization. (C) 2008 Elsevier B.V. All rights reserved
Lactose contaminant as steroid degradation enhancer
Purpose. By pharmaceutical processes and in the presence of solid excipients physical-chemical changes are known to occur, leading to increased rate of chemical degradation. The purpose of this work was to determine the critical aspects in the stability of a steroid in the presence of a commonly used excipient, lactose. Methods. A steroid was either mixed or wet granulated with lactose with different particle size. Results. Small lactose particles lead to a higher degree of degradation. Degradation was enhanced under warm humid conditions although the presence of water alone could not account for this effect. Lactose-phosphate, a known intrinsic contaminant in lactose is demonstrated to enhance the degradation of the steroid. Stability was improved in high purity lactose and deteriorated upon extra addition of phosphates. Since the exposure to the contaminant is a function of the surface area of the lactose, particle size differences of the excipient have a clear consequence. High shear granulated lactose granules exhibit a heterogeneous composition; large granules consist of small primary particles and vice versa. It is shown that the large granules, composed of the small primary lactose particles reveal the highest degree of degradation. Granule composition dictates the stability profile of the granules. Conclusion. The lactose contaminant and grandule composition dictates the stability profile of the granules and mixtures
Granule breakage during drying processes
The drying of wet granules often involves an unwanted and uncontrolled size reduction. Current FDA PAT guidance stresses importance of process control and understanding. The aim of this study is to determine and understand the breakage phenomena during drying processes in order to control these processes. High shear granulated lactose granules with water as binding liquid were dried during variable periods. Subsequently the (partially) dried granules were exposed to agitation by the impeller and chopper in the granulator. Granule characterization revealed that the change in granule size of (partially) dried granules is dependent on-water content and follows a three phase system characterized by a growth, plateau and breakage phase. The derived yield stress of the granules is a function of velocity. From this it is concluded that in the plateau phase above minimum water content, stress behavior of granules can be described with Rumpfs' dynamic granule strength, whereas below minimum water content (breakage phase) granule strength is determined by the solid bridges. The extent and velocity of stress and water content of the granules during the process determine the size reduction phenomena. (c) 2006 Elsevier B.V. All rights reserved