The in vitro antimalarial activity of clofazimine and seven of its analogues, all TMP(tetramethyl-piperidyl group)-derivatives except 8669, against the R8-1 and pfUP-1 laboratory strains of Plasmodium falciparum was investigated using a flow cytometric procedure. The flow cytometric method was compared with microscopy and radiometry for efficiency in quantitating the level of parasitemia in malaria cultures. The flow cytometric method compared well, as determined by the 81and and Altman measure of agreement, with both microscopy and radiometry and was chosen for use in this study due to its speed, precision and convenience (includes a fixing step that allows samples to be evaluated at anyone time). The riminophenazine agents were found to exhibit antimalarial action of varying degrees: B669, B4100, B4103, B4112 and B4158 showed the best activity followed by B4121 and B4169. Clofazimine did not exhibit any activity at concentrations up to 2µg/ml in this system. Their effective concentrations in vitro were comparable to that of standard antimalarial agents such as chloroquine. The agents B4103 and B4112 exhibited additive antimalarial activities when combined with chloroquine. The inclusion of the TMP group and extent of halogenation of six of the riminophenazines tested indicate that it is these structural properties which are the major determinants of the antiplasmodial activity. This is the first study to establish an antiplasmodial activity of riminophenazines and further tests are necessary to establish their antiparasitic mode of action and therapeutic potential in animal models of experimental chemotherapy. / Dissertation (MSc)--University of Pretoria, 2010. / Pharmacology / unrestricted

Claritromicina e clofazimina têm sido utilizadas no tratamento da hanseníase e tuberculose e também em infecções pelo complexo Mycobacterium avium, complicação comum em pacientes que se encontram em estágios avançados da síndrome da imunodeficiência adquirida (SIDA). Como os dados sobre a toxicidade de esquemas terapêuticos que incluem estes fármacos são escassos, o presente estudo teve como objetivo determinar os efeitos adversos destas terapias, por meio da avaliação dos parâmetros hematológicos, hemostáticos e bioquímicos e a correlação destes parâmetros com as doses testadas e destas com a concentração plasmática dos medicamentos administrados, intraperitonealmente, em ratos machos Wistar, em monoterapia, em regime de doses única (50, 100 e 200mg/kg de peso) e múltipla (100mg/kg). Clofazimina, em regime de dose única, provocou aumento no número de eritrócitos e redução dos índices eritrocitométricos VCM e CHCM. Em regime de dose múltipla, claritromicina provocou aumento de leucócitos e de células mono e polimorfonucleares. Ambos os fármacos, em dose única, parecem inverter a proporção entre células mono e polimorfonucleares. Foi observado aumento do número de células polimorfonucleares e células em degeneração, ocasionados tanto por clofazimina como pela claritromicina. Em regime de dose única, clofazimina e claritromicina prolongaram o TP. Claritromicina, quando administrada em dose múltipla, causou este mesmo efeito e também o prolongamento do TTPA. Os resultados da avaliação da função hepática mostraram resultados inconclusivos com relação às dosagens de AST, ALT e fosfatase alcalina, porém, foi observado aumento dos níveis plasmáticos de ?-GT provocado pela clofazimina, em regime de dose única. Claritromicina induziu aumento dos níveis de ?-GT, em regime de doses única e múltipla, e provocou elevação de bilirrubinas total e direta, em dose única. Houve aumento das concentrações plasmáticas dos fármacos à medida que as doses administradas aumentaram, apesar da claritromicina exibir um comportamento farmacocinético não-linear. Portanto, clofazimina e claritromicina provocam alterações hematológicas, hemostáticas e bioquímicas e os resultados de concentração plasmática são valiosos para avaliação de efeitos adversos em estudos comparativos de monoterapia e associação entre os medicamentos. / Clarithromycin and clofazimine have been used to treat leprosy and tuberculosis as well as infections of Mycobacterium avium complex, an ordinary complication in patients who are in advanced stage of Acquired Immunodeficiency Syndrome (AIDS). As the data about the toxicity of therapeutic schemes including those drugs are scarce, this research had the aim to determine the adverse effects of those therapies, through the evaluation of hematological, hemostatic and biochemical parameters and the relationship between these parameters and doses tested and between doses and plasma concentrations of drugs administered intraperitoneally, in male Wistar rats, in monotherapy, in single (50, 100 and 200mg/kg body wt), and multiple (100mg/kg body wt) doses regime. Clofazimine, in single dose regime, increased the number of erythrocytes, and it decreased the red cells indices MCV and MCHC. In multiple dose regime, clarithromycin increased the number of leukocytes and mononuclear and polymorphonuclear cells. Both the drugs, in single dose, seem to invert the proportion between mononuclear and polymorphonuclear cells. It was observed an increase in the number of polymorphonuclear cells and cells under degeneration caused by clofazimine and clarithromycin. In single dose regime, clofazimine and clarithromycin prolonged PT. When clarithromycin was administered in multiple dose, it brought about this same effect and also it prolonged aPTT. The results of hepatic function evaluation showed inconclusive results about AST, ALT and alkaline phosphatase levels, but it was observed an increase of U-GGT plasma levels provoked by clofazimine, in single dose regime. Clarithromycin brought about an increase of U-GGT plasma levels, in single and multiple dose regime, and caused an increase of total and direct bilirrubin, in single dose. An increase of plasma concentration of drugs was observed as administered doses were increased, though clarithromycin has nonlinear pharmacokinetics behavior. Therefore, clofazimine and clarithromycin induce hematological, hemostatic and biochemical alterations and the results of plasmatic concentration are valuable to evaluate adverse effects in comparative research of monotherapy and association between drugs.

Claritromicina e clofazimina têm sido utilizadas no tratamento da hanseníase e tuberculose e também em infecções pelo complexo Mycobacterium avium, complicação comum em pacientes que se encontram em estágios avançados da síndrome da imunodeficiência adquirida (SIDA). Como os dados sobre a toxicidade de esquemas terapêuticos que incluem estes fármacos são escassos, o presente estudo teve como objetivo determinar os efeitos adversos destas terapias, por meio da avaliação dos parâmetros hematológicos, hemostáticos e bioquímicos e a correlação destes parâmetros com as doses testadas e destas com a concentração plasmática dos medicamentos administrados, intraperitonealmente, em ratos machos Wistar, em monoterapia, em regime de doses única (50, 100 e 200mg/kg de peso) e múltipla (100mg/kg). Clofazimina, em regime de dose única, provocou aumento no número de eritrócitos e redução dos índices eritrocitométricos VCM e CHCM. Em regime de dose múltipla, claritromicina provocou aumento de leucócitos e de células mono e polimorfonucleares. Ambos os fármacos, em dose única, parecem inverter a proporção entre células mono e polimorfonucleares. Foi observado aumento do número de células polimorfonucleares e células em degeneração, ocasionados tanto por clofazimina como pela claritromicina. Em regime de dose única, clofazimina e claritromicina prolongaram o TP. Claritromicina, quando administrada em dose múltipla, causou este mesmo efeito e também o prolongamento do TTPA. Os resultados da avaliação da função hepática mostraram resultados inconclusivos com relação às dosagens de AST, ALT e fosfatase alcalina, porém, foi observado aumento dos níveis plasmáticos de ?-GT provocado pela clofazimina, em regime de dose única. Claritromicina induziu aumento dos níveis de ?-GT, em regime de doses única e múltipla, e provocou elevação de bilirrubinas total e direta, em dose única. Houve aumento das concentrações plasmáticas dos fármacos à medida que as doses administradas aumentaram, apesar da claritromicina exibir um comportamento farmacocinético não-linear. Portanto, clofazimina e claritromicina provocam alterações hematológicas, hemostáticas e bioquímicas e os resultados de concentração plasmática são valiosos para avaliação de efeitos adversos em estudos comparativos de monoterapia e associação entre os medicamentos. / Clarithromycin and clofazimine have been used to treat leprosy and tuberculosis as well as infections of Mycobacterium avium complex, an ordinary complication in patients who are in advanced stage of Acquired Immunodeficiency Syndrome (AIDS). As the data about the toxicity of therapeutic schemes including those drugs are scarce, this research had the aim to determine the adverse effects of those therapies, through the evaluation of hematological, hemostatic and biochemical parameters and the relationship between these parameters and doses tested and between doses and plasma concentrations of drugs administered intraperitoneally, in male Wistar rats, in monotherapy, in single (50, 100 and 200mg/kg body wt), and multiple (100mg/kg body wt) doses regime. Clofazimine, in single dose regime, increased the number of erythrocytes, and it decreased the red cells indices MCV and MCHC. In multiple dose regime, clarithromycin increased the number of leukocytes and mononuclear and polymorphonuclear cells. Both the drugs, in single dose, seem to invert the proportion between mononuclear and polymorphonuclear cells. It was observed an increase in the number of polymorphonuclear cells and cells under degeneration caused by clofazimine and clarithromycin. In single dose regime, clofazimine and clarithromycin prolonged PT. When clarithromycin was administered in multiple dose, it brought about this same effect and also it prolonged aPTT. The results of hepatic function evaluation showed inconclusive results about AST, ALT and alkaline phosphatase levels, but it was observed an increase of U-GGT plasma levels provoked by clofazimine, in single dose regime. Clarithromycin brought about an increase of U-GGT plasma levels, in single and multiple dose regime, and caused an increase of total and direct bilirrubin, in single dose. An increase of plasma concentration of drugs was observed as administered doses were increased, though clarithromycin has nonlinear pharmacokinetics behavior. Therefore, clofazimine and clarithromycin induce hematological, hemostatic and biochemical alterations and the results of plasmatic concentration are valuable to evaluate adverse effects in comparative research of monotherapy and association between drugs.

Yes / Objectives: Resistance-associated variants (RAVs) in Rv0678, a regulator of the MmpS5-MmpL5 efflux pump, have been shown to lead to increased MICs of bedaquiline (2- to 8- fold) and clofazimine (2- to 4-fold). The prevalence of these Rv0678 RAVs in clinical isolates and their impact on treatment outcomes are important factors to take into account in bedaquiline treatment guidelines. Methods: Baseline isolates from two bedaquiline MDR-TB clinical trials were sequenced for Rv0678 RAVs and corresponding bedaquiline MICs were determined on 7H11 agar. Rv0678 RAVs were also investigated in non-MDRTB sequences of a population-based cohort. Results: Rv0678 RAVs were identified in 23/347 (6.3%) of MDR-TB baseline isolates. Surprisingly, bedaquiline MICs for these isolates were high (>0.24 mg/L, n¼8), normal (0.03 0.24 mg/L, n¼11) or low(<0.03 mg/L, n¼4). A variant at position 11 in the intergenic region mmpS5–Rv0678 was identified in 39 isolates (11.3%) and appeared to increase the susceptibility to bedaquiline. In non-MDR-TB isolates, the frequency of Rv0678 RAVs was lower (6/ 852 or 0.7%). Competition experiments suggested that rifampicin was not the drug selecting for Rv0678 RAVs. Conclusions: RAVs in Rv0678 occur more frequently in MDR-TB patients than previously anticipated, are not associated with prior use of bedaquiline or clofazimine, and in the majority of cases do not lead to bedaquiline MICs above the provisional breakpoint (0.24mg/L). Their origin remains unknown. Given the variety of RAVs in Rv0678 and their variable effects on the MIC, only phenotypic drug-susceptibility methods can currently be used to assess bedaquiline susceptibility. / This work was supported by Janssen Pharmaceutica. N. C. was supported by a Baekeland PhD scholarship from the Flemish Institute for Scientific Technology (IWT 130308, Belgium). C. J. M., L. R. and B. d. J. were supported by a European Research Council Starting Grant INTERRUPTB (311725).

Actuellement, la tuberculose (TB) est la deuxième maladie infectieuse au monde avec une forte prévalence et un taux de mortalité annuel élevé. L'Organisation Mondiale de la Santé (OMS) a récemment dévoilé sa nouvelle stratégie, appelée «Mettre fin à la tuberculose», pour la prévention, le contrôle et l'éradication de cette maladie. Les résultats doivent mener à une éradication totale d'ici au 2035. Dans le cadre des objectifs spécifiques de cette stratégie, l'OMS a intégré la recherche de nouvelles connaissances et innovations scientifiques qui améliorent et augmentent l'efficacité des traitements qui sont utilisés contre cette maladie.Deux des stratégies pharmaceutiques qui ont été les plus étudiées pendant ces dernières années ayant comme objectif principal d'augmenter l'efficacité globale des régimes thérapeutiques utilisés dans la tuberculose comprennent: i) l'incorporation de médicaments antituberculeux de première et de seconde ligne dans des systèmes de libération contrôlé, en particulier les nanoparticules polymères (NP); et, ii) l'utilisation de produits naturels (par exemple, des extraits de plantes ou des composés isolés) comme adjuvants, c'est-à-dire des substances qui, lorsqu'elles sont administrées conjointement avec des médicaments existants, augmentent leur activité.Dans ce contexte, ce travail de recherche a conduit au développement de deux stratégies pour rendre le traitement de la tuberculose plus efficace. D'une part, on a proposé le développement d´une nanomédecine à base de NP biodégradables contenant un principe actif antituberculeux de deuxième ligne, la clofazimine (CFM). D´autre part, on a conçu le développement des systèmes adjuvants provenant d'extraits végétaux obtenus à partir de l´arbre Schinus molle, lesquels ont été aussi incorporés dans des NP (biodégradables et non biodégradables). Dans cette deuxième stratégie, l'objectif principal a été l'obtention de potentielles nanoformulations qui permettent une application sûre de ces extraits par diverses voies d'administration (p. ex. par voie intraveineuse, pulmonaire ou orale).Dans ce travail, le Chapitre I est une revue de la littérature sur l'étude des produits naturels (spécifiquement des extraits de plantes) qui ont été proposés comme des agents potentiellement antibactériens contre Mycobacterium tuberculosis [etc...] / Tuberculosis is a chronic infection located in the lungs during the early stages of this disease. The World Health Organization, annually, registers about 9 million new cases and 1.5 million deaths. In addition, the development of multi-drug resistant strains of Mycobacterium tuberculosis has complicated the global control of tuberculosis. An effective control for this epidemic can be based on two main pharmaceutical strategies. First, the development of novel formulations based on controlled release systems for antitubercular drugs which could be used for establishing more effective therapeutic schemes. A second approach can be focused on development of natural products nanoformulations (e.g. natural extracts) for their application as adjuvants for tuberculosis treatment. In this context, the present research work was focused on the design and development of a nanomedicine based on biodegradable nanoparticles and an antitubercular drug of second line (clofazimine). In addition, organic extracts obtained from Schinus molle were formulated into nanoparticles in order to use them as adjuvants in tuberculosis treatment. The characterization of the nanoformulations established a direct relationship between the physicochemical properties (i.e. particle size, surface charge and release profile) of the active-loaded polymeric nanoparticles (with drug or extract) and the increase of the antitubercular activity in vitro. Particularly, additional in vitro tests showed that nanoencapsulation of S. mole extract decreased their toxicity as compared to a non-encapsulated extract. In conclusion, nanoformulations loaded with clofazimine or extract of S. molle showed to have a high potential to be applied in efficient therapeutic schemes for tuberculosis treatment

Claritromicina e clofazimina são utilizadas no tratamento da hanseníase e em infecções causadas pelo complexo Mycobacterium avium, comuns em portadores do HIV. Devido à escassez de dados sobre a toxicidade de esquemas terapêuticos que associam estes fármacos, este estudo teve por objetivo avaliar os efeitos adversos desta terapia, em ratos machos Wistar, por meio da determinação de parâmetros hematológicos, hemostáticos e bioquímicos e correlação destes parâmetros com a dose e concentração plasmática dos medicamentos, em regime de doses únicas e múltiplas. Para tanto foram realizados: a) contagem global e específica de leucócitos (método manual) e ensaios de fagocitose e burst oxidativo de neutrófilos (citometria de fluxo); b) contagem de plaquetas (método manual), tempo de protrombina, tempo de tromboplastina parcial ativada, níveis plasmáticos dos fatores VII e X (método automatizado); c) níveis séricos de gama-glutamiltransferase (método cinéticocolorimétrico) e bilirrubinas total e direta (método colorimétrico); d) concentrações plasmáticas dos fármacos (Cromatografia Líquida de Alta Eficiência). Não houve diferenças entre as concentrações plasmáticas dos fármacos administrados em monoterapia ou politerapia. Entretanto, tanto clofazimina como claritromicina tiveram redução das concentrações plasmáticas em regime de doses múltiplas, quando comparadas à dose única. Houve aumento do número de leucócitos (dose múltipla) e de células polimorfonucleares (doses única e múltipla) nos grupos tratados com claritromicina em monoterapia ou associada à clofazimina, e redução das células mononucleares, em doses única e múltipla, nos mesmos grupos. Os fármacos parecem inverter a proporção entre células mono e polimorfonucleares. Observou-se aumento do burst oxidativo nos animais tratados com os fármacos tanto em monoterapia como em regime de politerapia. Entretanto, não houve diferença entre os tratamentos com os fármacos em relação ao controle DMSO, em dose única. Em doses múltiplas, os tratamentos com clofazimina e claritromicina em monoterapia ou politerapia estimularam o aumento do burst oxidativo (p < 0,0001) em relação ao controle DMSO. Não foram verificadas diferenças na fagocitose entre os grupos tratados e controle, tanto em dose única como em doses múltiplas. Tempo de protrombina e tempo de tromboplastina parcial ativada não foram alterados com o uso dos fármacos. Os fatores VII e X da coagulação tiveram aumento de suas atividades quando os ratos foram tratados em regime de dose múltipla com claritromicina, em regime de mono e politerapia. Houve perda de cerca de 8 % do peso de ratos tratados com clofazimina e 18 % daqueles tratados com claritromicina ou com a associação dos dois fármacos, no esquema de doses múltiplas, entretanto não houve diferença entre os grupos quando foram avaliados os níveis de gama-glutamiltransferase e bilirrubinas total e direta. Concluindo, clofazimina e claritromicina provocam alterações hematológicas, hemostáticas e bioquímicas e os resultados de concentração plasmática são valiosos para avaliação de efeitos adversos em estudos comparativos de monoterapia e politerapia entre os medicamentos. / Clarithromycin and clofazimine have been used to treat leprosy and infections caused by Mycobacterium avium complex in HIV patients. Because there are few data about the toxicity of treatment regimens involving these drugs, this study aimed to evaluate the adverse effects of this therapy in male Wistar rats through the determination of hematological, haemostatic and biochemical parameters and correlate them with the dose and plasma concentrations of drugs, under a single and multiple dose regimen. Evaluation was performed as follows: a) Global and specific count of leukocytes (manual method), phagocytosis and oxidative burst of neutrophils assays (flow cytometry), b) platelet count (manual method), prothrombin time, activated partial thromboplastin time, plasma levels of factors VII and X (automated method), c) Gamma-glutamyltransferase (kinetic-colorimetric method) and total and direct bilirubin serum levels (colorimetric method), d) plasma concentrations of drugs (High-Performance Liquid Chromatography). There were no differences between plasma concentrations of the drugs administered in monotherapy or polytherapy. However, the concentrations of both clofazimine and clarithromycin have decreased in plasma in multiple dose regimen compared to single dose. There was an increase in the number of leukocytes (multiple dose) and polymorphonuclear cells (single and multiple doses) in the groups treated with clarithromycin in monotherapy or in association with clofazimine, and a decrease in the number of mononuclear cells in single and multiple doses, in the same groups. Both drugs seemed to reverse the proportion between mononuclear and polymorphonuclear cells. The oxidative burst was observed in animals treated with drugs in polytherapy or in monotherapy, however there was no difference between the treatment with drugs and the control with DMSO in single dose. In multiple doses, treatment with clofazimine and clarithromycin in monotherapy or polytherapy stimulated the increase of oxidative burst (p <0.0001) compared to control. There were no differences in phagocytosis between the treated and control groups in single and multiple doses. Prothrombin time and activated partial thromboplastin time have not changed with the use drugs. In contrast, the activities of factors VII and X of coagulation have increased when rats were treated with multiple doses regimes with clarithromycin alone or in association with clofazimine. There was weight loss of 8% in rats treated with clofazimine and 18% in those treated with clarithromycin or with association of the drugs in the multiple doses regimen. However, there was no difference between the groups when gammaglutamyltransferase and total and direct bilirubin levels were analyzed. Therefore, clofazimine and clarithromycin induce hematological, hemostatic and biochemical changes and the results of plasma concentration is valuable for assessing adverse effects in comparative studies of monotherapy and polytherapy of these drugs.

Made available in DSpace on 2014-12-17T14:13:58Z (GMT). No. of bitstreams: 1 ElaineLMB.pdf: 288894 bytes, checksum: f70a81fe61f9c843b53868be13773200 (MD5) Previous issue date: 2007-06-22 / PURPOSE: To evaluate the capacity of clofazimine (CFZ) to control cutaneous activity of systemic lupus erythematosus (SLE), compared with chloroquine diphosphate (CDP). METHODS: A prospective, randomized, controlled, double blind clinical trial was carried out in thirty-three patients with SLE and cutaneous lesions (malar rash and/or discoid lupus and/or subacute cutaneous lupus), after approval by the respective Ethics Committee. Sixteen patients received clofazimine - 100mg/day (CFZ group) and 17 received chloroquine diphosphate - 250mg/day (CDP group), during six months. Both groups applied broad-spectrum sunscreens twice a day. The dose of prednisone was kept stable during the study. Cutaneous lesions were evaluated by 2 blinded observers and photographed at baseline and at months 1, 2, 4 and 6. RESULTS: Thirty-three patients began and 27 completed the 6 months of treatment. The groups were homogeneous and comparable in terms of demographic and clinical characteristics. Five CFZ-patients and one CDP-patients dropped out due to severe flare of disease requiring other treatment. At the end of the study, 12 CFZ-patients (75%) and 14 CDP-patients (82,4%) presented complete or near-complete remission of skin lesions; intention-to-treat analysis showed no significant difference in the response rates between groups. Side effects in both groups were frequent, but patients didn t have to discontinue the drugs. CONCLUSIONS: Clofazimine and chloroquine were effective in controlling cutaneous lesions in SLE patients / Objetivo: Avaliar a efic?cia da clofazimina (CFZ) no tratamento das les?es cut?neas do l?pus eritematoso sist?mico (LES), comparando-a com o difosfato de cloroquina (DFC). M?todos: Ap?s aprova??o pelo Comit? de ?tica em Pesquisa da Universidade Federal do Rio Grande do Norte (UFRN), foi realizado um estudo intervencional duplo-cego, controlado e rand?mico, com 33 pacientes portadores de LES e les?es cut?neas em atividade (eritema malar t?pico e/ou les?o disc?ide e/ou l?pus cut?neo subagudo). Um grupo recebeu 100 mg de CFZ (n=16 pacientes) e o outro grupo recebeu 250 mg de DFC (n=17 pacientes), durante seis meses. Ambos os grupos usaram protetor solar, duas vezes ao dia. Durante o per?odo de observa??o, a dose do corticoster?ide dos pacientes foi mantida est?vel. Resultados: Trinta e tr?s pacientes iniciaram e 27 completaram os 06 meses do estudo. Cinco pacientes do grupo CFZ e um do grupo DFC foram retirados, devido a manifesta??es sist?micas graves do LES, para o tratamento adequado a cada caso. Ao final do estudo, utilizando a an?lise inten??o de tratar , 12 pacientes do grupo CFZ (75%) e 14 do grupo DFC (82,4%) obtiveram melhora completa ou quase completa das les?es cut?neas. Os efeitos colaterais foram freq?entes em ambos os grupos, mas nenhum paciente necessitou interromper o tratamento. Conclus?es: A clofazimina mostrou-se eficaz, semelhante ao difosfato de cloroquina, no controle das les?es cut?neas do LES

Claritromicina e clofazimina são utilizadas no tratamento da hanseníase e em infecções causadas pelo complexo Mycobacterium avium, comuns em portadores do HIV. Devido à escassez de dados sobre a toxicidade de esquemas terapêuticos que associam estes fármacos, este estudo teve por objetivo avaliar os efeitos adversos desta terapia, em ratos machos Wistar, por meio da determinação de parâmetros hematológicos, hemostáticos e bioquímicos e correlação destes parâmetros com a dose e concentração plasmática dos medicamentos, em regime de doses únicas e múltiplas. Para tanto foram realizados: a) contagem global e específica de leucócitos (método manual) e ensaios de fagocitose e burst oxidativo de neutrófilos (citometria de fluxo); b) contagem de plaquetas (método manual), tempo de protrombina, tempo de tromboplastina parcial ativada, níveis plasmáticos dos fatores VII e X (método automatizado); c) níveis séricos de gama-glutamiltransferase (método cinéticocolorimétrico) e bilirrubinas total e direta (método colorimétrico); d) concentrações plasmáticas dos fármacos (Cromatografia Líquida de Alta Eficiência). Não houve diferenças entre as concentrações plasmáticas dos fármacos administrados em monoterapia ou politerapia. Entretanto, tanto clofazimina como claritromicina tiveram redução das concentrações plasmáticas em regime de doses múltiplas, quando comparadas à dose única. Houve aumento do número de leucócitos (dose múltipla) e de células polimorfonucleares (doses única e múltipla) nos grupos tratados com claritromicina em monoterapia ou associada à clofazimina, e redução das células mononucleares, em doses única e múltipla, nos mesmos grupos. Os fármacos parecem inverter a proporção entre células mono e polimorfonucleares. Observou-se aumento do burst oxidativo nos animais tratados com os fármacos tanto em monoterapia como em regime de politerapia. Entretanto, não houve diferença entre os tratamentos com os fármacos em relação ao controle DMSO, em dose única. Em doses múltiplas, os tratamentos com clofazimina e claritromicina em monoterapia ou politerapia estimularam o aumento do burst oxidativo (p < 0,0001) em relação ao controle DMSO. Não foram verificadas diferenças na fagocitose entre os grupos tratados e controle, tanto em dose única como em doses múltiplas. Tempo de protrombina e tempo de tromboplastina parcial ativada não foram alterados com o uso dos fármacos. Os fatores VII e X da coagulação tiveram aumento de suas atividades quando os ratos foram tratados em regime de dose múltipla com claritromicina, em regime de mono e politerapia. Houve perda de cerca de 8 % do peso de ratos tratados com clofazimina e 18 % daqueles tratados com claritromicina ou com a associação dos dois fármacos, no esquema de doses múltiplas, entretanto não houve diferença entre os grupos quando foram avaliados os níveis de gama-glutamiltransferase e bilirrubinas total e direta. Concluindo, clofazimina e claritromicina provocam alterações hematológicas, hemostáticas e bioquímicas e os resultados de concentração plasmática são valiosos para avaliação de efeitos adversos em estudos comparativos de monoterapia e politerapia entre os medicamentos. / Clarithromycin and clofazimine have been used to treat leprosy and infections caused by Mycobacterium avium complex in HIV patients. Because there are few data about the toxicity of treatment regimens involving these drugs, this study aimed to evaluate the adverse effects of this therapy in male Wistar rats through the determination of hematological, haemostatic and biochemical parameters and correlate them with the dose and plasma concentrations of drugs, under a single and multiple dose regimen. Evaluation was performed as follows: a) Global and specific count of leukocytes (manual method), phagocytosis and oxidative burst of neutrophils assays (flow cytometry), b) platelet count (manual method), prothrombin time, activated partial thromboplastin time, plasma levels of factors VII and X (automated method), c) Gamma-glutamyltransferase (kinetic-colorimetric method) and total and direct bilirubin serum levels (colorimetric method), d) plasma concentrations of drugs (High-Performance Liquid Chromatography). There were no differences between plasma concentrations of the drugs administered in monotherapy or polytherapy. However, the concentrations of both clofazimine and clarithromycin have decreased in plasma in multiple dose regimen compared to single dose. There was an increase in the number of leukocytes (multiple dose) and polymorphonuclear cells (single and multiple doses) in the groups treated with clarithromycin in monotherapy or in association with clofazimine, and a decrease in the number of mononuclear cells in single and multiple doses, in the same groups. Both drugs seemed to reverse the proportion between mononuclear and polymorphonuclear cells. The oxidative burst was observed in animals treated with drugs in polytherapy or in monotherapy, however there was no difference between the treatment with drugs and the control with DMSO in single dose. In multiple doses, treatment with clofazimine and clarithromycin in monotherapy or polytherapy stimulated the increase of oxidative burst (p <0.0001) compared to control. There were no differences in phagocytosis between the treated and control groups in single and multiple doses. Prothrombin time and activated partial thromboplastin time have not changed with the use drugs. In contrast, the activities of factors VII and X of coagulation have increased when rats were treated with multiple doses regimes with clarithromycin alone or in association with clofazimine. There was weight loss of 8% in rats treated with clofazimine and 18% in those treated with clarithromycin or with association of the drugs in the multiple doses regimen. However, there was no difference between the groups when gammaglutamyltransferase and total and direct bilirubin levels were analyzed. Therefore, clofazimine and clarithromycin induce hematological, hemostatic and biochemical changes and the results of plasma concentration is valuable for assessing adverse effects in comparative studies of monotherapy and polytherapy of these drugs.

Chemotherapy of tuberculosis (TB), a disease caused by Mycobacterium tuberculosis (M. tuberculosis), is successful against actively-growing bacilli but ineffective against dormant/persistent organisms, found mainly in a protective lipid-laden granuloma, possibly necessitating the use of lipophilic antibiotics. In vitro, these bacilli are encased in lipid-rich biofilms. In this study, the antimycobacterial activity of one such agent, clofazimine, and its nanoparticle formulation, have been investigated against Mycobacterium smegmatis (M. smegmatis), as a surrogate for M. tuberculosis, by determining the bacteriostatic and bactericidal activities of the native (NC) and spray-dried (SDC) preparations of this agent on planktonic and biofilm populations, as well as their effects on biofilm formation and its lipid compositions, specifically free mycolic acid (FM) content. Both preparations were comparable, being bacteriostatic for rapidly-proliferating bacilli, bactericidal for slow-growing, biofilm-producing sessile bacteria, but ineffective against non-replicating, biofilm-encased M. smegmatis organisms. However, similar studies in M. tuberculosis are required. / Dissertation (MSc)--University of Pretoria, 2013. / Immunology / Unrestricted

Cancer is responsible for upward of 13% of human deaths. Contemporary chemotherapy of disseminated cancer is often thwarted by dose limiting systemic toxicity and by multi-drug resistance (MDR). Riminophenazines are a novel class of potential anticancer agents that possess a potent multi-mechanistic antineoplastic action. Apart from their broad action against intrinsic, non-classical resistance, Riminophenazines inhibit the action of Pgp and hypothetically all ABC transporters demonstrating their great utility against classical MDR. Considering that combination chemotherapy is the norm, the vision directing R&D efforts was that Riminophenazines could be used with benefit within many standard chemotherapeutic regimes. The strategic intent of this project was to attain improved therapeutic benefit for patients through gains in both pharmaco dynamic and pharmacokinetic specificity for cancer cells over what is currently available. Tactically, this was driven through the use of synergistic Fixed-Ratio Drug Combinations (FRDC) encapsulated within tumour-targeting Nanoparticulate Drug Delivery Systems (NDDS). Long-term aims of this R&D project were to: 1) Screen FRDC of clofazimine (B663) and the lead derivative (B4125) with etoposide, paclitaxel and vinblastine for synergistic drug interactions in vitro. 2) Design, assemble and characterize a novel nanoparticulate, synergistic, anticancer co-formulation. 3) Evaluate the in vivo safety and efficacy of the developed product/s in accordance with international regulatory guidelines. Using the median effect and combination index equations, impressive in vitro synergistic drug interactions (CI<1) were shown for various FRDC of the three standard chemotherapeutics tested (etoposide, paclitaxel and vinblastine) in combination with either B663 or B4125 against MDR neoplastic cell cultures. Considering in vitro results and with the view to advance quickly to clinical studies, the already approved clofazimine (B663) was elected as the combination partner for paclitaxel (PTX). Considering the potency and wide action of PTX, a novel coformulation (designed to circumvent drug resistance) has the potential to greatly impact upon virtually all cancer types, particularly if selectively delivered through innovative delivery systems and loco-regional administration. A passively tumour targeting, micellular NDDS system called Riminocelles™ that encapsulates a synergistic FRDC of B663 and PTX has been designed, assembled using thin film hydration methods and characterized in terms of drug loading, particle size, zeta potential, CMC and drug retention under sink conditions. An acute toxicity and a GLP repeat dose toxicity study confirmed Riminocelles to be well tolerated and safe at clinically relevant dosages whilst Taxol® (QDx7) produced statistically significant (P<0.05) weight loss within 14 days. The same study demonstrated statistically significant (P<0.05) tumour growth delays superior to that of Taxol at an equivalent PTX dosage of 10 mg/kg. Importantly, all components (amphiphiles and drugs) used in assembly of Riminocelles are already individually approved for medicinal use - this promotes accelerated development towards advanced clinical trials and successful registration. Although these results are very promising (outperforming Taxol), this system was however found in a pharmacokinetic study to suffer from in vivo thermodynamic instability due to the high concentration (abundance) of albumin present in plasma. For this reason, in vivo longevity within circulation, permitting passive tumour accumulation was not fully realized. A second NDDS called the RiminoPLUS™ imaging system was additionally developed. This lipopolymeric nanoemulsion system has successfully entrapped Lipiodol® Ultra fluid (an oil based contrast agent) within the hydrophobic core of a monodisperse particle population with a size of roughly 100 nm and a stability of one week. This formulation is therefore thought capable of CT imaging of tumour tissue and drug targeting after either intravenous or loco-regional injection. In vivo proof of the imaging concept is warranted. The results of this study serve to highlight the great potential of in vitro optimized synergistic FRDC against drug resistant cancers. Lipopolymeric micelles are an effective way to formulate multiple hydrophobic drugs for intravenous administration and present a means by which cancer can be readily targeted; provided that the delivery system possess the prerequisite in vivo stability and surface attributes. Further experiments exploring synergistic drug and biological combinations as well as “intelligent” NDDS actively guided through specific molecular recognition are called for. / Thesis (PhD)--University of Pretoria, 2012. / Pharmacology / unrestricted