Nanoparticulate drug delivery systems (NDDS) such as nanocrystals, nanosuspensions, solid-lipid nanoparticles often formulated for the bioavailability enhancement of poorly soluble drug candidates are stabilized by a mixture of excipients including surfactants and polymers. Most literature studies have focused on the interaction of excipients with the NDDS surfaces while ignoring the interaction of excipients in solution and the extent to which the solution-state interactions influence the affinity and capacity of adsorption. Mechanisms by which excipients stabilize NDDS and how this information can be utilized by formulators a priori to make a rational selection of excipients is not known. The goals of this dissertation work were (a) to determine the energetics of interactions between HPMC and model surfactants and the extent to which these solution-state interactions modulate the adsorption of these excipients onto solid surfaces, (b) to determine and characterize the structures of various aggregate species formed by the interaction between hydroxypropyl methylcellulose (HPMC) and model surfactants (nonionic and ionic) in solution-state, and (c) to extend these quantitative relationships to interpret probable mechanisms of mixed adsorption of excipients onto the model NDDS surface. A unique approach utilizing fluorescence, solution calorimetry and adsorption isotherms was applied to tease apart the effect of solution state interactions of polymer and surfactant on the extent of simultaneous adsorption of the two excipients on a model surface. The onset of aggregation and changes in aggregate structures were quantified by a fluorescence probe approach with successive addition of surfactant. In the presence of HPMC, the structures of the aggregates formed were much smaller with an aggregation number (Nagg) of 34 as compared to micelles (Nagg ~ 68) formed in the absence of HPMC. The strength of polymer-surfactant interactions was determined to be a function of ionic strength and hydrophobicity of surfactant. The nature of these structures was characterized using their solubilization power for a hydrophobic probe molecule. This was determined to be approximately 35% higher in the polymer-surfactant aggregates as compared to micelles alone and was attributed to a significant increase in the number of aggregates formed and the increased hydrophobic microenvironment within these aggregates at a given concentration of surfactant. The energetics of the adsorption of SDS, HPMC, and SDS-HPMC aggregate onto nanosuspensions of silica, which is the model solid surface were quantified. A strong adsorption enthalpy of 1.25 kJ/mol was determined for SDS adsorption onto silica in the presence of HPMC as compared to the negligible adsorption enthalpy of 0.1 kJ/mol for SDS alone on the silica surface. The solution depletion and HPMC/ELSD methods showed a marked increase in the adsorption of SDS onto silica in the presence of HPMC. However, at high SDS concentrations, a significant decrease in the adsorbed amount of HPMC onto silica was determined. This was further corroborated by the adsorption enthalpy that showed that the silica-HPMC-SDS aggregation process became less endothermic upon addition of SDS. This suggested that the decrease in adsorption of HPMC onto silica at high SDS concentrations was due to competitive adsorption of SDS-HPMC aggregates wherein SDS is displaced/desorbed from silica in the presence of HPMC. At low SDS concentrations, an increase in adsorption of SDS was due to cooperative adsorption wherein SDS is preferentially adsorbed onto silica in the presence of HPMC. This adsorption behavior confirmed the hypothesis that the solution-state interactions between pharmaceutical excipients such as polymers and surfactants would significantly impact the affinity and capacity of adsorption of these excipients on NDDS surfaces.

Advancements in nanoparticle drug delivery of anticancer agents require mathematical models capable of predicting in vivo formulation performance from in vitro characterization studies. Such models must identify and incorporate the physicochemical properties of the therapeutic agent and nanoparticle driving in vivo drug release. This work identifies these factors for two nanoparticle formulations of anticancer agents using an approach which develops mechanistic mathematical models in conjunction with experimental studies. A non-sink ultrafiltration method was developed to monitor liposomal release kinetics of the anticancer agent topotecan. Mathematical modeling allowed simultaneous determination of drug permeability and interfacial binding to the bilayer from release data. This method also quantified the effects of topotecan dimerization and surface potential on total amount of drug released from these liposomal formulations. The pH-sensitive release of topotecan from unilamellar vesicles was subsequently evaluated with this method. A mechanistic model identified three permeable species in which the zwitterionic lactone form of topotecan was the most permeable. Ring-closing kinetics of topotecan from its carboxylate to lactone form were found to be rate-limiting for topotecan drug release in the neutral pH region. Models were also developed to non-invasively analyze release kinetics of actively-loaded liposomal formulations of topotecan in vivo. The fluorescence excitation spectra of released topotecan were used to observe release kinetics in aqueous solution and human plasma. Simulations of the intravesicular pH in the various release media indicated accelerated release in plasma was a consequence of increased intravesicular pH due to ammonia levels in the plasma instead of alterations in bilayer integrity. Further studies were performed to understand the roles of dimerization, ion-pairing, and precipitation on loading and release kinetics obtained from actively-loaded topotecan. Extension of this type of modeling for other types of nanoparticles was illustrated with doxorubicin-conjugated polymeric micelles. Mathematical modeling of experimental studies monitoring doxorubicin release identified conjugation stability during storage, hydrazone hydrolysis kinetics, and unconjugated doxorubicin partitioning affected micellar doxorubicin release. This work identifies several of the key parameters governing drug release from these liposomal and micellar nanoparticles and lays the framework for future development of in vivo release models for these formulations.

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 113-119.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 4 uppsatser.

Thesis Univ. College London, 2006. / Includes bibliographical references and indexes.

BK channels are well studied targets of acute ethanol action. They play a prominent role in neuronal excitability and have been shown to play a significant role in behavioral ethanol tolerance in invertebrates. The focus of my work centers on the effects of alcohol on the BK channel and comprises studies that examine how subcellular location affects acute ethanol sensitivity and how duration of acute alcohol exposure impacts the development of rapid tolerance. My results also provide potential mechanisms which underlie acute sensitivity and rapid tolerance. I first explore BK channel sensitivity to ethanol in the three compartments (dendrite, cell body, and nerve terminal) of magnocellular neurons in the rat hypothalamic-neurohypophysial (HNS) system. The HNS system provides a particularly powerful preparation in which to study the distribution and regional properties of ion channel proteins because the cell bodies are physically separated from the nerve terminals. Using electrophysiological and immunohistochemical techniques I characterize the BK channel in each of the three primary compartments and find that dendritic BK channels, similar to somatic channels, but in contrast to nerve terminal channels, are insensitive to alcohol. Furthermore, the gating kinetics, calcium sensitivity, and iberiotoxin sensitivity of channels in the dendrite are similar to somatic channels but sharply contrast terminal channels. The biophysical and pharmacological properties of somatodendritic vs. nerve terminal channels are consistent with the characteristics of exogenously expressed αβ1 vs. αβ4 channels, respectively. Therefore, one possible explanation for my findings is a selective distribution of β1 subunits to the somatodendritic compartment and β4 subunits to the terminal compartment. This hypothesis is supported immunohistochemically by the appearance of distinct punctate β1 or β4 channel clusters in the membrane of somatodendritic or nerve terminal compartments, respectively. In conclusion, I found that alcohol sensitivity of BK channels within the HNS system is dependent on subcellular location and postulate that β-subunits modulate ethanol sensitivity of HNS BK channels. In the second and primary focus of my thesis I explore tolerance development in the striatum, a brain region heavily implicated in addiction. Numerous studies have demonstrated that duration of drug exposure influences tolerance development and drug dependence. To further elucidate the mechanisms underlying behavioral tolerance I examined if BK channel tolerance was dependent on duration of alcohol exposure using patch clamp techniques in cultured striatal neurons from P8 rats. I found that persistence of rapid tolerance is indeed a function of exposure time and find it lasts surprisingly long. For example, after a 6 hr exposure to 20 mM ethanol, acute sensitivity was still suppressed at 24 hrs withdrawal. However, after a 1 or 3 hr exposure period, sensitivity had returned after only 4 hrs. I also found that during withdrawal from a 6 hr but not a 3 hr exposure the biophysical properties of BK channels change and that this change is correlated with an increase in mRNA levels of the alcohol insensitive STREX splice variant. Furthermore, BK channel properties during withdrawal from a 6 hr exposure to alcohol closely parallel the properties of STREX channels exogenously expressed in HEK293 cells. In conclusion I have established that BK channels develop rapid tolerance in striatal neurons, that rapid tolerance is dependent upon exposure protocol, and is surprisingly persistent. These findings present another mechanism underlying BK channel tolerance and possibly behavioral tolerance. Since these phenomena are dependent on duration of drug exposure my results may find relevance in explaining how drinking patterns impact the development of alcohol dependence in humans.

The body of work presented here is a compendium of the multiple steps required for an investigator initiated trial of an existing medication (Valproic Acid- VPA) for a new indication (Retinitis Pigmentosa – RP). The chapters are listed in logical and chronological order of the process. In order to access patient records an expedited Institutional Review Board (IRB) application for retrospective chart review was submitted (Chapter 1). These records enabled the statistical analysis which not only laid the framework for the trial design, but also became the basis for two manuscripts (Chapter 2). Protocol development informed by the preliminary human studies (Chapter 3) was an instrumental part of the Investigational New Drug (IND) application (Chapter 3.5). This protocol along with the extensive case report forms that detail the intended data to be collected are included in the IND application. Because the Phase II clinical trial proposed attempting to identify the specific RP mutations of the subjects utilizing a National Eye Institute (NEI) study that enabled free genotyping services, two IRB applications were submitted (Chapter 3.6). The first was for approval of the NEI genotyping protocol, the second involved the VPA intervention. Two very different sources of funding for this trial were attempted (Chapter 4) – the NIH via the Challenge Grant mechanism and a private eye disease foundation (Foundation Fighting Blindness). In Chapter 5 I detail the alternate study designs that were considered and developed for this trial (and ultimately abandoned). Finally, in Chapter 6, I formally detail my suggestions to aid in the development of a comprehensive investigator initiated core facility at UMMMC. The goal of this project was two-fold. The first was to learn the entire process of trial and protocol design both from a Umass Institutional perspective as well as from the perspective of the FDA. The second goal was the very real prospect of helping patients with a blinding disease. This work was successful on both counts. IRB approval was received for all the submitted applications. The complexity and uniqueness of many aspects of these submissions culminated in a comprehensive learning experience. The process of working with the Umass Research Pharmacy as well as developing the industry contacts and know-how to develop a workable and financially feasible placebo were both particularly important learning experiences. FDA approval of the IND submission was also received, and the process of pre-communication and delving into the considerable and ever-changing rules and regulations resulted in an extensive and valuable knowledge base. While the practicality of funding has limited the ability of this trial to move forward at this point, given the extensive framework laid by this body of work, we are actively pursuing other opportunities. The third outcome of this work, while not as intentional, was the considerable process of determining the specific competencies and infrastructure that exist at UMMMC to enable investigator initiated drug intervention studies. While this institution is clearly moving rapidly in the direction of translational research, the many needs of these studies are often only clearly understood when the process is specifically undertaken. In completing the approval of this Phase II clinical trial, I was not only able to better understand and define the existing capabilities of UMMMC for this kind of research, I was able to add to that infrastructure when the existing knowledge or skill set was not available. In this manner, I was able to inform and guide many of the support personnel who guided me and have become a part of the strategic direction of UMMMC towards clinical translational research.

Neste trabalho, é proposto o desenvolvimento de instrumentação e procedimentos analíticos automáticos empregando fotometria em fase sólida para determinação de zinco em produtos farmacêuticos e água. Para implementação do procedimento analítico, todo o sistema foi acoplado a um computador através de uma interface eletrônica. Um software escrito em linguagem QuickBASIC 4.5 permite que o computador efetue o controle da adição das soluções da amostra e do eluente e faça aquisição de dados. O sistema de detecção é constituído de uma cela de fluxo contendo, um LED e um fotodiodo. A geometria da cela de fluxo possibilitava variar o comprimento do caminho óptico. O procedimento para determinação do zinco foi baseado na retenção do analito na fase sólida (TAN-C18), previamente inserida na cela de fluxo, seguido de uma etapa de eluição. Com os parâmetros analíticos otimizados obteve-se resposta linear na faixa de 0,05 a 0,85 mg L-1 (R=0,995), limite detecção de 9,3 \'mü\'g L-1, coeficiente de variação de 1,4% (n=10) e frequência de amostragem de 36 det h-1. O módulo de análise foi aplicado em amostras de produtos farmacêuticos e a exatidão dos resultados foi averiguada comparando com os resultados obtidos por espectrometria de emissão óptica com plasma acoplado indutivamente ICP-OES. Aplicando-se tratamento estatístico apropriado, observou-se que não havia diferença significativa ao nível de confiança de 95 %. Estes resultados comprovam a viabilidade do emprego de fotômetro de LED em fotometria em fase sólida / In this work, it is propose the instrumentation and automatic analytic procedures development using solid phase spectrophotometry for determination of zinc in pharmaceutical preparations and water. For analytic procedure implementation, the whole system was coupled to a computer through an electronic interface. A written software in language QuickBASIC 4.5 allows the computer makes the sample solutions addition control and of eluent and do data acquisition. The detection system is constituted of a flow cell contend, a LED and a photodiode. The flow cell geometry enabled vary the length of the optical path. The procedure for zinc determination was going based in analyte retention in the solid phase (TAN-C18), previously inserted in the flow cell, followed by an elution stage. With the optimized analytic parameters it btained lineal answer in the band of 0,05 to 0,85 mg L-1 (R=0,995), limit detection of 9,3 \'mü\'g L-1, variation coefficient of 1,4% (n=10) and sampling throughput of 36 det h-1. The analysis module was going applied in pharmaceutical preparations samples and the exactness of the results was going ascertained comparing with the results obtained for inductively coupled plasma optic emission spectrometry of with ICP- its. Applying appropriated statistical treatment, it observed that there wasn\'t significant difference to the reliable level of 95 %. These results prove photometer job viability of LED in photometry in solid phase

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-03-10T14:07:49Z No. of bitstreams: 1 rafaelpimentelpinheiro.pdf: 5642312 bytes, checksum: c0018e11016a4083a03c156be84fe1ad (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-13T19:16:19Z (GMT) No. of bitstreams: 1 rafaelpimentelpinheiro.pdf: 5642312 bytes, checksum: c0018e11016a4083a03c156be84fe1ad (MD5) / Made available in DSpace on 2017-03-13T19:16:19Z (GMT). No. of bitstreams: 1 rafaelpimentelpinheiro.pdf: 5642312 bytes, checksum: c0018e11016a4083a03c156be84fe1ad (MD5) Previous issue date: 2015-07-30 / Palicourea rigida Kunth, pertencente à família Rubiaceae, tem sido utilizada na medicina popular para o tratamento de inflamações e infecções do trato urinário, do aparelho reprodutor feminino e para doenças da pele. Do ponto de vista químico, triterpenos, iridoides, flavonoides e alcaloides têm sido identificados na espécie. O objetivo do presente trabalho foi realizar uma caracterização química e avaliar as atividades anti-inflamatória tópica e cicatrizante de P. rigida. Folhas secas e pulverizadas foram extraídas em etanol P.A. por maceração estática seguida de rota-evaporação para obtenção do extrato etanólico (EEPR). EEPR foi submetido à partição líquido/líquido, adquirindo as frações hexânica, diclorometânica, em acetato de etila e butanólica. EEPR foi analisado por CLUE-UV-EM, enquanto a fração hexânica por CG-EM. A fração em acetato de etila foi fracionada por cromatografia em coluna de Sephadex LH-20 e a substância isolada foi elucidada por RMN 1H e 13C e espectrometria de massas. A partir de EEPR, foi desenvolvido uma formulação de creme à base Lanette® (cEEPR). A atividade antiinflamatória tópica de EEPR foi avaliada pelos modelos de edema de orelha em camundongos Swiss empregando óleo de cróton, ácido araquidônico, capsaicina e fenol. A atividade cicatrizante de EEPR e cEEPR foi investigada em ratos Wistar através do modelo de lesões por excisão cutânea. Análises histopatológicas e as atividades das enzimas mieloperoxidase (MPO) e N-acetil-β-d-glucoronidase (NAG) foram também determinadas. Loganina e quercetina 3-6- O-acetil-β-glicosídeo foram identificadas no EEPR por CLUE-UV-EM, enquanto ácido palmítico, fitol, ácido linoleico, esqualeno, gama tocoferol, vitamina E, campesterol, estigmasterol e gama sitosterol foram caracterizadas na fração hexânica por CG-EM. A partir da fração em acetato de etila, o flavonoide quercetina 3-O-β-D-glicosídeo foi isolado e sua estrutura elucidada. EEPR apresentou atividade anti-inflamatória tópica nos diferentes modelos através da redução da massa e espessura do edema, assim como pela diminuição do processo inflamatório observado pelas análises histopatológicas e inibição das atividades de MPO e NAG. EEPR e cEEPR demonstraram atividade cicatrizante pela diminuição da área da lesão e aumento do grau de contração, bem como pela estimulação do processo de cicatrização e redução das atividades de MPO e NAG. Os resultados indicam que P. rigida é rica em substâncias bioativas que podem ser responsáveis pelas atividades anti-inflamatória e cicatrizante. / Palicourea rigida Kunth, belonging to the Rubiaceae family, has been used in folk medicine for the treatment of inflammation and infections of the urinary tract, female reproductive tract and skin conditions. From the chemical point of view, triterpenes, iridoids, flavonoids and alkaloids have been identified in species. The aim of this study was to perform a chemical characterization and evaluate the topical anti-inflammatory and wound healing activities of P. rigida. Dried and powdered leaves were extracted in ethanol PA by static maceration followed by rota-evaporation for obtaining ethanol extract (EEPR). EEPR was subjected to partition liquid/liquid to obtain the hexane, dichloromethane, ethyl acetate and butanol fractions. EEPR was analyzed by UPLC-UV-MS, while the hexane fraction by GC-MS. The ethyl acetate fraction was separated by column chromatography with Sephadex LH-20 and the isolated compound was elucidated by 1H and 13C NMR and mass spectrometry. From the EEPR, a dermatological formulation was developed using the cream-based Lanette® (cEEPR). The topical anti-inflammatory activity of EEPR was evaluated by the ear edema models in mice Swiss using croton oil, arachidonic acid, capsaicin and phenol. The wound healing activity of EEPR and cEEPR was investigated in Wistar rats through the model of skin lesions. Histopathological analysis and activity of the enzyme myeloperoxidase (MPO) and N-acetyl- β-D-glucuronidase (NAG) were also determined. Loganin and quercetin 3-6-O-acetyl-β- glucoside were identified in EEPR by UPLC-UV-MS, while palmitic acid, phytol, linoleic acid, squalene, gamma tocopherol, vitamin E, campesterol, stigmasterol and sitosterol were characterized in the hexane fraction by GC-MS. From the fraction in ethyl acetate, the flavonoid quercetin 3-O-β-D-glucoside was isolated and its structure elucidated. EEPR showed topical anti-inflammatory activity in different models by reducing the the mass and thickness of the edema, as well as through the decrease in the inflammatory process observed by histopathological analysis and inhibition of the MPO and NAG activities. EEPR and cEEPR demonstrated wound healing activity by decrease the area of lesion and increase the contraction degree, as well as stimulate the healing process and reduce the MPO and NAG activities. The results indicate that P. rigida is rich in bioactive substances which may be responsible for the anti-inflammatory and wound healing activities.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-12T12:13:46Z No. of bitstreams: 1 milenemachadominateli.pdf: 5060284 bytes, checksum: 446ee2d6824758d7358e4ba2cb4f755a (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-12T15:46:30Z (GMT) No. of bitstreams: 1 milenemachadominateli.pdf: 5060284 bytes, checksum: 446ee2d6824758d7358e4ba2cb4f755a (MD5) / Made available in DSpace on 2017-05-12T15:46:30Z (GMT). No. of bitstreams: 1 milenemachadominateli.pdf: 5060284 bytes, checksum: 446ee2d6824758d7358e4ba2cb4f755a (MD5) Previous issue date: 2015-07-13 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Vernonia polyanthes Less, família Asteraceae, popularmente conhecida no Brasil como assa-peixe, tem sido utilizada no tratamento de afecções do aparelho respiratório, problemas renais e gastrointestinais, feridas, fraturas e torções, contusões e luxações e, ainda, indicada como tônica, emenagoga, diurética e cicatrizante. O objetivo deste trabalho foi avaliar o potencial toxicológico e as atividades anti-inflamatória tópica e cicatrizante e desenvolver um creme dermatológico a partir do extrato etanólico das folhas de V. polyanthes Less. Folhas secas e pulverizadas foram submetidas à extração em etanol PA por maceração estática seguida de rotaevaporação para obtenção do extrato etanólico de V. polyanthes (EEVP). Parâmetros bioquímicos, hematológicos, morfológicos e histopatológicos foram determinados em ratos Wistar após 15 e 30 dias de tratamento por via oral com 100, 200 e 400 mg/kg de EEVP. O creme dermatológico do extrato etanólico de V. polyanthes (cEEVP) foi desenvolvido nas concentrações 0,10, 0,25 e 0,50% seguido de estudo de estabilidade. A atividade anti-inflamatória tópica de cEEVP foi avaliada pelos métodos de edema de orelha induzido por óleo de cróton, fenol e ácido araquidônico, enquanto EEVP e cEEVP foram usados no ensaio da atividade cicatrizante através de induções de lesões cutâneas. Análises histopatológicas e avaliação da atividade das enzimas mieloperoxidase (MPO) e N-Acetil-β-D-glicorominidase (NAG) complementaram os ensaios farmacológicos. Na avaliação da toxicidade, EEVP não alterou os parâmetros bioquímicos, hematológicos e histopatológicos, mas promoveu modificações nos níveis lipídicos e enzimas hepáticas nos grupos tratados com EEVP. O cEEVP apresentou conformidades adequadas no estudo de estabilidade e juntamente com o EEVP demonstrou efeitos anti-inflamatório tópico e cicatrizante. Os resultados poderão contribuir com a Política Nacional de Plantas Medicinais e Fitoterápicos através da difusão do conhecimento e da comprovação científica das aplicações terapêuticas de V. polyanthes. / Vernonia polyanthes Less, Asteraceae family, popularly known in Brazil as assa-peixe, has been used to treat diseases of the respiratory tract, kidney and gastrointestinal problems, wounds, fractures and sprains, bruises and dislocations, and also indicated as tonic, emmenagogue, diuretic and healing. The aim of this work was to investigate the toxicological potential and topical anti-inflammatory and healing activities and develop a dermatological cream from the ethanol extract of V. polyanthes leaves. Dried and powdered leaves were extracted in ethanol PA by static maceration for obtaining dry ethanol extract (EEVP) using a rotaevaporator. Parameters Biochemical, hematologic, morphological and histopathological were determined in Wistar rats after 15 and 30 days of treatment orally with 100, 200 and 400 mg/kg EEVP. Dermatological cream of EEVP (cEEVP) was developed at the concentrations of 0.10, 0.25 and 0.50% and evaluated through stability study. The topical anti-inflammatory activity of cEEVP was assessed by ear edema induced by croton oil, phenol and arachidonic acid, while the wound healing activity was performed by cutaneous lesions test using EEVP and cEEVP. Histopathological analysis and evaluation of the myeloperoxidase (MPO) and N-acetyl-β-D-glicorominidase (NAG) activities were also determined. In the evaluation of toxicity, EEVP did not modify the biochemical, hematological and histopathological parameters, but promoted alterations in lipid and liver enzymes levels. The cEEVP showed adequate conformities in the stability study and together with the EEVP demonstrated topical anti-inflammatory and wound healing effects. The results may contribute to the National Policy of Medical Plants and Herbal through the dissemination of knowledge and scientific evidence of the therapeutic applications of V. polyanthes.