Thesis (Ph. D.)--University of Wisconsin--Madison, 1980. / Typescript. Vita. Includes bibliographical references (leaves 255-270).

Ph.D.

This dissertation is based on the theory and applications of the most commonly used solubilization techniques: pH adjustment, cosolvency, micellization, complexation, and the combinations of pH adjustment with one of the other techniques.Chapter 1 provides an overview for the methods which are available to formulate a poorly water-soluble drug based on its administration route.Chapter 2 applies these commonly used techniques to solubilize two structurally related anticancer drugs. The efficiency of each technique is compared for both drugs side by side. It is observed that each technique is more efficient on the drug which has less polarity. However, the achievable final drug concentration in a formulation depends not only on the efficiency of the applied technique, but also on the drug's water solubility.Chapter 3 emphasizes the overall effectiveness of each technique on drugs which have different physicochemical properties. Solubilization profiles for the above techniques are generated for twelve compounds, eight of which are ionizable and studied under both unionized and ionized conditions. This chapter illustrates that the efficiency of the cosolvency, micellization, and complexation on both unionized and ionized drug species can be predicted from their polarities. Thus, the solubility of an ionizable drug can be estimated by using a given solubilizing excipient at any pH to meet the dose requirement.Chapter 4 studies the effect of cosolvent on complex stability. A series of alcohols were used to illustrate the effect of cosolvent size and polarity on the solubilization of a compound. It is proposed that a ternary drug-ligand-cosolvent complex is formed in these combined systemsThis dissertation provides guidance for the selection of a solubilization technique for a compound based on the physicochemical properties and the dose requirement.

Cell membranes, or plasma membranes, play an essential role in the structure and the function of living cells. In 1972, the fluid mosaic membrane model was the first unifying paradigm of membrane structure. It is no longer considered adequate because evidence of many non-homogeneous lipid structures in both natural and model membranes have been discovered over the past thirty years. The field of membrane biophysics now uses updated versions of the mosaic model, which consists of the complex mixture of different lipid species. The lipid species found in natural membranes produce a range of dynamic, laterally segregated, non-homogeneous domains, which exist on time scales ranging from microseconds to minutes. The cell membrane is an enclosing or separating membrane that acts as a selectively permeable barrier within living things. It consists of the phospholipid bilayer with associated embedded proteins, integral (intrinsic) and peripheral (extrinsic) proteins used for various biological activities. Proteins, especially integral membrane proteins, perform a range of key functions vital to the cell, such as controlled movement of molecules across lipid bilayers, as well as participating in cell signaling and motility. The major obstacle to studying membrane proteins is the tendency for some of their properties to change and the proteins themselves may be denatured when extracted by detergents. One of the most significant approaches to solve this problem is the use of styrene-maleic acid copolymers (SMAs), which offers detergent-free solubilization of embrane, which allows studies of membrane proteins to be done in very small systems. The main goal of this thesis is to examine the effects of these polymers on the interior of the lipid bilayer. With these, membrane proteins can be extracted from cell membranes while conserving a patch of near-native membrane around them. It has been suggested but not proven that proteins in nanodiscs reside in a hydrophobic environment that is identical to that found in the native cell membrane. Moreover, I also investigate the kinetics of membrane solubilization by SMA by using UV/visible spectrophotometer. In addition, I examine how lipid packing in the nanodiscs is affected by the presence of the polymers and how it depends on polymer composition by using SMA variants with different styrene-to-maleic acid ratios.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains ix, 116 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

The aqueous solubilization power of several series of micellar homopolymers and copolymers (polysoaps) is investigated. Using five insoluble or poorly water-soluble dyes, comparisons of the capacities are made with respect ot the influence of structural variables such as the polymer backbone, the polymer geometry, the comonomer content, and the charge of the hydrophilic group. Some guidelines for polysoap structures suited for efficient solubilization are established. Noteworthy is that the solubilization capacities of the polysoaps are neither linked to the ability to reduce the surface tension of water, nor to the polarity of the solubilization sites deduced from spectroscopic probes.

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Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains viii, 42 p. : ill. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains vii, 44 p. : ill. Includes abstract. Includes bibliographical references.

Orientador: Everlon Cid Rigobelo / Banca: Rinaldo Cesar de Paula / Banca: Leonardo Lucas Madaleno / Resumo: Para um bom desenvolvimento e produtividade a cultura de eucalipto exige, principalmente nos primeiros estágios do seu desenvolvimento, grande quantidades de fósforo (P), que é um nutriente essencial para o metabolismo do eucalipto, sua ausência afeta o desenvolvimento comprometendo sua produtividade. Devido à baixa disponibilidade desse nutriente nos solos brasileiros, altas doses de adubos fosfatados são utilizadas a fim de suprir a necessidade nutricional da planta, o que não obtém sucesso, devido à precipitação e combinação com as partículas do solo. O objetivo do presente estudo foi avaliar a atividade das bactérias Azospirillum brasilense e Bacillus subtilis em solubilizar fósforo para mudas de eucalipto no período inicial do seu desenvolvimento. As mudas foram replantadas em vasos e receberam os inóculos em três doses, sendo 1ml, 10ml e 20ml na concentração 1x10⁷. Após o plantio as mudas foram aspergidas diariamente com água e permaneceram em condições ambientais, sendo avaliadas nos períodos de 40 e 70 dias após o plantio. Comparando os parâmetros de crescimento das mudas de eucalipto e os períodos de avaliação, não houve diferenças significativas entre os tratamentos. O número de bactérias totais variou entre tratamentos e períodos, mas não se verificou aumento significativo quando comparados ao controle. As concentrações de fósforo solúvel no solo, não apresentaram diferenças significativas entre si, os tratamentos que receberam os inóculos bacterianos apresentaram ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: For a good development and productivity the eucalyptus crop demands, mainly in the early stages of its development, great amounts of phosphorus (P), which is an essential nutrient for the metabolism of eucalyptus, its absence affects the development compromising its productivity. Due to the low availability of this nutrient in Brazilian soils, high doses of phosphate fertilizers are used in order to supply the nutritional need of the plant, which is not successful due to precipitation and combination with the soil particles. The objective of the present study was to evaluate the activity of the bacteria Azospirillum brasilense and Bacillus subtilis in solubilizing phosphorus for eucalyptus seedlings in the initial period of its development. The seedlings were replanted in pots and inoculated in three doses, being 1ml, 10ml and 20ml in the 1x10 concentração concentration. After planting the seedlings were sprayed daily with water and remained in environmental conditions, being evaluated in the periods of 40 and 70 days after planting. Comparing the growth parameters of eucalyptus seedlings and the evaluation periods, there were no significant differences between treatments. The number of total bacteria varied between treatments and periods, but there was no significant increase when compared to the control. The concentrations of soluble phosphorus in the soil did not present significant differences among them, the treatments that received the bacterial inocula had similar conc... (Complete abstract click electronic access below) / Mestre