Erythromycin is a macrolide antibiotic with a spectrum similar to penicillin and is used mainly in the treatment of infections caused by gram-positive organisms. Since its discovery in 1952, erythromycin has achieved wide-spread clinical use. Susceptibility of erythromycin base to inactivation by acid results in decreased availability following exposure to acidic gastric fluids. Formulation of acid resistant dosage forms and the preparation of acid stable chemical derivatives have been attempted to improve absorption and subsequent clinical efficacy . Two of the most commonly used erythromycin derivatives are the stearic acid salt (erythromycin stearate) and the lauryl sulphate salt of the propionyl ester (erythromycin estolate). Although it has been known for many years that erythromycin is susceptible to acid degradation, very few reports on the stability of erythromycin in aqueous solutions appear in the literature. In this study, a high-performance liquid chromatographic system using electrochemical detection was employed for a kinetic study of erythromycin degradation. The effect of varying acid pH on the degradation rate of both erythromycin base and erythromycin stearate, and the effect on the hydrolysis rate of erythromycin estolate is presented. In addition, the effect of temperature on erythromycin degradation was also investigated. Until recently, the majority of pharmacokinetic and bioavailability studies have utilized relatively non-specific microbiological assay procedures. However, in this study a solid phase extraction, followed by the use of a high-performance liquid chromatographic system using electrochemical coulometric detection was employed for the determination of erythromycin in biological fluids. Human volunteers each received enteric coated erythromycin base pellets in capsule dosage form and also film coated erythromycin stearate tablets on separate occasions. Results from the clinical trials revealed the enteric coated erythromycin base pellets had a greater bioavailability than the film coated erythromycin stearate tablets. Computer fitting of data revealed no intra-volunteer variability in elimination rate constants, suggesting differences in serum levels following administration of both dosage forms are due to variation in absorption. Results from the clinical trials were also compared with those obtained from a further trial, during which the same volunteers received erythromycin estolate

Amifostine (WR-2721, delivered as Ethyol) is a radioprotector agent that reduces the likelihood of early and/or late biological effects by eliminating free radical particles during ionizing radiation fraction (radiotherapy). It activates in under normal tissues conditions to reduce mutation and fraction in DNA. Among 4000 prodrug compounds, amifostine is the only agent has been approved from the US Food and Drug Administration in clinical purposes. The main effective mechanisms of amifostine are based on scavenging for free radical, improving for DNA repair step and indication of cellular hypoxia. In the same time, this drug is not widely used around the world for different reasons mainly its high cost and toxicity level (lethal dose). Conjugating a monoclonal antibody with amifostine by a suitable linker is a process of Antibody Drug Conjugate producing immuno-radioprotector molecule hypothesis. Administrated molecule is an approach of targeted delivery therapy that increases the dosage uptake into particular area of treatment to minimize the dose distribution in non-targeted area in the body. In the present work, we proposed a three-compartment system model to simulate the two-pore theory pathway of an immuno-radioprotector molecule when it is crossing the physiological barriers. The model investigated its distribution and elimination in porous media (with both large and small pores) within a pharmacokinetics compartmented model approach.

The present experiments investigated the effects of different antidepressant treatments on dopamine (DA) transmission by employing in vivo microdialysis in the nucleus accumbens (NAC) and the striatum of freely moving rats. The treatments were: a) the tricyclic antidepressant desipramine (DMI), b) the novel antidepressant drug bupropion, and c) electrically induced seizures (ECS). The following results were obtained: 1) Neither acute (5 mg/kg), nor chronic (5 mg/kg, b.i.d. X 21) DMI influenced basal interstitial concentrations of DA in the NAC or the striatum. Chronic DMI did not influence apomorphine (25 μg/kg, s.c.)-induced decreases in extracellular DA in the NAC. In contrast, d-amphetamine (1.5 mg/kg, s.c.)-induced increases in extracellular DA were significantly enhanced in the NAC (not in striatum) of the chronic DMI group. d-Amphetamine-induced hypermotility was also enhanced in the chronic DMI group. 2) Bupropion (10, 25 and 100 mg/kg, i.p.) increased extracellular striatal DA concentrations in a dose-, time-, and action potential-dependent manner. Bupropion produced similar responses in the NAC. The in vivo neurochemical effects of bupropion were compared with the effects of other DA uptake inhibitors such as d-amphetamine, GBR 12909, cocaine, nomifensine, methylphenidate, and benztropine by direct administration of the drugs to the striatum via the perfusion fluid in increasing concentrations (1 to 1000 μM). The rank order of potency of these drugs as determined by the increases in extracellular DA produced by 10 or 100 μM (following correction for dialysis efficiency of the test compounds in vitro) was: GBR 12909> benztropine> amphetamine= nomifensine= methylphenidate> cocaine> bupropion. Simultaneous in vivo microdialysis in the NAC and striatum was employed to investigate the effects of chronic (10 mg/kg, b.i.d. X 21) bupropion treatment on bupropion (25 mg/kg, i.p.)-induced increases in extracellular DA concentrations. The effect of the challenge bupropion injection was significantly enhanced in the NAC (not in striatum) of the chronic bupropion group. Bupropion-induced hyperlocomotion was also enhanced in the chronic bupropion group. 3) Following a single ECS (150 V, 0.75 sec) interstitial concentrations of DA in the NAC and striatum increased sharply to 130% and 300%, respectively. The ECS-induced DA increase in the striatum was Ca⁺⁺-sensitive, partially TTX-independent, and was not influenced by barbiturate-induced anaesthesia. Seizure activity induced by flurothyl did not influence dialysate DA concentrations from the striatum, but increased dialysate DA from the NAC to 150%. These results suggest that the ECS-induced DA release in the striatum (not in the NAC) is related to the passage of current and not to the seizure activity. A course of ECS (8 treatments, one every second day) did not influence basal extracellular DA concentrations in the striatum or the NAC, while it significantly increased the DA metabolites in the striatum. Chronic ECS did not influence apomorphine (25 μg/kg, s.c.)-induced decreases in extracellular DA in the NAC. d-Amphetamine (1.5 mg/kg s.c.)-induced increases in extracellular DA were significantly enhanced in the NAC of the chronic ECS group. d-Amphetamine-induced hypermotility was also enhanced in the chronic ECS group. These results provide in vivo neurochemical confirmation that chronically administered DMI or ECS do not produce DA autoreceptor subsensitivity. They also demonstrate that chronic DMI- or chronic ECS-induced increases in the locomotor stimulant effects of d-amphetamine are accompanied by a potentiation of its effects on interstitial DA concentrations in the NAC. Moreover, these results demonstrate that chronic bupropion-induced behavioral sensitization is accompanied by a selective potentiation of its effects on interstitial DA concentrations in the NAC. Taken together, the present data provide direct neurochemical evidence that these antidepressant treatments can increase the functional output of the meso-accumbens dopaminergic system. / Medicine, Faculty of / Graduate

Many methods exist in the literature for the prediction of pharmacokinetic parameters which describe drug distribution in rat and human, such as tissue-to-plasma partition coefficients (Kps) and volume of distribution (Vss). However, none of these methods make use of the in vivo information obtained at the early stages of the drug development process in the form of plasma concentration vs. time profiles. The overall aim of the presented study was to improve upon an existing Kp prediction method by making use of the distribution information contained within this experimental data. Chapter 2 shows that Kp values can be successfully obtained experimentally, but that this process is expensive and time-consuming. Chapter 3 compares six Kp prediction methods taken from the literature for their ability to predict the Kp values of 80 drugs. The Rodgers et al. model was found to be the most accurate, with over 77% of predictions within 3-fold of experimental values. This Chapter also discusses the Vss prediction ability of some of these methods, with the Poulin & Theil and Rodgers et al. models shown to be the most accurate predictors for rat Vss and human Vss respectively. Chapter 4 investigates the relationship between muscle Kp and the Kps of all other tissues, to show that experimental muscle Kp can be used as a surrogate from which all other non-adipose Kp values can be predicted. However, the predictions made using this method were shown to be less accurate than predictions made by the Rodgers et al. model for the same dataset of drugs. A relationship was identified between muscle Kp and tumour Kp in rat, suggesting a potential way to predict tumour Kp in the future. In Chapter 5, a novel method is developed whereby Kp predictions made by the Rodgers et al. model are updated using prior information obtained from the in vivo concentration-time profile. These updated values are then used within a physiologically-based pharmacokinetic (PBPK) model and are shown in Chapter 6 to generate improved predictions for other pharmacokinetic parameters such as Vss and clearance in both rat and human. 100% of human Vss predictions made by the most accurate of the novel methods presented here were within 3-fold of experimental values, compared to 68.8% of predictions made by the Rodgers et al. model. The work presented here has highlighted the need for a more accurate method for the prediction of Kp values, and has addressed this need by generating a model which improves upon the most accurate Kp prediction method currently found in the literature. This will lead to an increase in confidence in the use of predicted pharmacokinetic parameters within PBPK modelling.

Inflammatory ocular disease is an important cause of blindness and uveitis accounts for 1.0% of blind patients in Canada.¹ This disease can be particularly troublesome to treat, because the nature of the causal factor or factors and mechanisms of progressi n are usually unknown. Non-specific anti - inflammatory agents have been used orally and systemically with some success to treat uveitis, ²⁻⁸ but they may produce serious side effects both locally and elsewhere in the body.⁹̛¹²̛¹⁴ With prolonged use tolerance to these drugs may develop , making them ineffective. Recently a powerful immuno suppressive agent, Cyclosporine (Cy), used orally and systemically in the treatment of uveitis has shown promising results.¹⁶⁻¹⁹̛²⁸ However, its routine use is limited because of a narrow therapeutic index and renal toxicity. Several studies have shown that subconjunctival injection of a number of antineoplastic agents enhanced ocular absorption ²⁰⁻²⁴ in a traditional pharmacological sanctuary,¹³̛¹⁴ and circumvented the associated systemic side effects. Therefore, if Cy were administered subconjunctivally it might be possible to avoid the side effects associated with the oral and systemic routes, and at the same time provide higher levels of Cy to the eye. A protocol for the administration of Cy subconjunctivally was developed in New Zealand white rabbits, to study toxicity, ocular pharmacokinetics following equidose administration subconjunctivally and systemically and the effects of Cy on an animal model of uveitis. Subconjuntival administration of 5mg of Cy in O.lcc (Sandimmune I.V.(R) 50 mg/ml) weekly was found to be the maximum tolerated dose by the rabbitsˈ eye, and was superior to intravenous injection for ocular penetration while minimizing systemic exposure. The uveitis model showed that Cy was effective in reducing the inflammatory response and the earlier the application of Cy the milder the uveitis. The results from our study support the contention that local administration of Cy would lead to higher levels of Cy absorption and circumvent the side effects of systemic administration. This may facilitate the routine use of Cy in ocular inflammatory disease. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

Recent reports in the literature suggest that oral contraceptive steroid therapy may be implicated in the development of benign hepatic adenomas in women. Since estrogens and progestins are known to affect liver function, we studied effects of chronic administration of the oral contraceptive agents mestranol and norethindrone on various indices of hepatic integrity. Several hepatic mixed function oxidase activities were measured: benzo(a)pyrene hydroxylase, epoxide hydrase, aniline hydroxylase (Appendix II) and aminopyrlne N-demethylase (Appendix II). In addition, benzo(a)pyrene hydroxylase activity in lung tissue was measured. As an indication of whether metabolites of the contraceptive steroids were bound to liver macromolecules, irreversible binding of [³H]-benzopyrene was measured. Hepatic histopathology (light microscopy using hematoxylin and eosin stain and oil red 0 stain) was carried out to determine if functional alterations correlated with pathological changes in the liver. Comparisons were also made between ethanol treated and non-ethanol treated groups to determine if contraceptive steroid-associated hepatotoxiclty was enhanced by or would enhance, the hepatotoxiclty of ethanol administration. Female and male Wistar rats were pair-fed a nutritional liquid diet, Sustacal[sup R] (Mead Johnson) to which was added either sucrose or ethanol as 40% of calories. Oral contraceptive steroids were administered daily in the liquid, diet in the following doses: mestranol, 0.6 mg/kg per day, alone or in combination with norethindrone, 5.0 mg/kg per day. Initial short-term studies showed that the ethanol plus Sustacal[sup R] diet generally caused enzyme induction compared to the plain Sustacal[sup R] diet or the sucrose plus Sustacal[sup R] diet in animals treated for up to 6 weeks. Animals that were administered the contraceptive steroids for a similar time period also demonstrated hepatic microsomal enzyme induction. Enzyme activity in animals that received ethanol plus the contraceptive steroids was increased above that seen for each agent alone. Chronic studies showed that ethanol administration for 6 months produced hepatotoxiclty in both male and female rats. Hepatotoxiclty was observed functionally as decreased hepatic benzo(a)pyrene hydroxylase activity and histopathologically as increased fat accumulation in zone 3 of the liver lobules. It was found that administration of the contraceptive steroids to female rats tended to protect against ethanol-associated hepatotoxiclty. The protective effect was observed functionally as maintenance of control levels of hepatic benzo(a)pyrene hydroxylase activity and morphologically as lesser amounts of fat accumulation ln the liver. That is, there tended to be a correlation between the level of hepatic benzo(a)pyrene hydroxylase activity and histological fat accumulation as an indication of ethanol-associated hepatotoxiclty. A Sustacal associated phenomenon was evident in all animals in which hlstopathology was carried out. The "Sustacal effect" was observed, as mlcrodroplet fat accumulation ln zone 1 of the liver lobule. Contraceptive steroid treated females showed the least "Sustacal effect". Microsomal enzyme activity did not appear to be affected by the "Sustacal effect". It was concluded that the contraceptive steroids administered did not increase ethanol hepatotoxicity. Instead, it appeared that female sex steroids tended to attenuate ethanol-assoclated hepatotoxicity. There was no evidence to suggest that the oral contraceptive steroids were directly associated with overt hepatotoxicity. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

The nucleus may be the critical site for the activation of chemical carcinogens, and subsequently the initiation of neoplasia. However, isolated nuclei may be contaminated with endoplasmic reticulum, the major site of the drug metabolizing enzymes. One of the objectives of the present study was to determine whether the enzymes in isolated rat hepatic nuclei were of nuclear origin and, if so, to compare these enzymes with those in the microsomal fraction. The selective manipulation of nuclear enzymes would be a useful tool in determining their role in cellular toxicity. Recentrifugation experiments, with aryl hydrocarbon hydroxylase (AHH) activity as a marker, showed that isolated nuclei were not contaminated with endoplasmic reticulum in the form of microsomes formed upon homogenization. However, small "tags" of endoplasmic reticulum, continuous with the nuclear membrane, and indiscernable in electron micrographs, could remain following centrifugation and account for all of the measurable enzyme activity in the isolated nuclei. It was reasoned that if endoplasmic reticulum accounted for all of the activity, then the ratio of nuclear to microsomal activity for all enzymes determined should be the same. The ratios of epoxide hydrolase and AHH were found to differ in the two fractions. The simplest interpretation of these data was that drug metabolizing enzymes existed in the nuclei. However, the distribution of drug metabolizing enzymes throughout the endoplasmic reticulum is known to be heterogeneous and these "tags" could differ from the total endoplasmic reticulum (microsomes) in their enzyme make-up. Whether these enzymes are in the nuclear membrane, nucleoplasm, or as "tags" of endoplasmic reticulum, they represent activities in close proximity to potential target sites in the nucleus. The inhibition, induction, and activation characteristics of nuclear and microsomal enzymes were studied with the goal of selective manipulation of nuclear enzymes. The enzymes in the nuclear and microsomal fractions were found to differ' only in quantitative inducibility, and were identical in all other respects. Therefore, the selective manipulation of nuclear enzymes was not achieved. The induction of hepatic drug metabolizing enzymes is a measure of altered genetic expression in the liver. Inducers of drug metabolizing enzymes have also been shown to promote neoplasia in the liver. Therefore, studying the induction of such enzymes may lead to a further understanding of the mechanism of tumour promotion. Phenobarbital, 3-methylcholanthrene and pregnenolone-16α-carbonitrile produce three distinct induction responses. In the present study, spironolactone and trans-stiIbene oxide were shown to produce distinct induction responses, also. Spironolactone was shown to be a different inducer based on the protein band patterns observed following SDS-polyacrylamide gel electrophoresis of liver microsomes. trans-Stilbene oxide was found to produce a significantly different maximal level of AHH activity. The observation of five distinct induction responses suggests at least five recognition sites (receptors) mediating the pleiotropic actions of exogenous compounds in the liver. / Pharmaceutical Sciences, Faculty of / Graduate

A comprehensive method for the analysis of 11 target pharmaceuticals representing multiple therapeutic classes was developed for biological tissues (fish) and water. Water samples were extracted using solid phase extraction (SPE), while fish tissue homogenates were extracted using accelerated solvent extraction (ASE) followed by mixed-mode cation exchange SPE cleanup and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Among the 11 target pharmaceuticals analyzed, trimethoprim, caffeine, sulfamethoxazole, diphenhydramine, diltiazem, carbamazepine, erythromycin and fluoxetine were consistently detected in reclaimed water. On the other hand, caffeine, diphenhydramine and carbamazepine were consistently detected in fish and surface water samples. In order to understand the uptake and depuration of pharmaceuticals as well as bioconcentration factors (BCFs) under the worst-case conditions, mosquito fish were exposed to reclaimed water under static-renewal for 7 days, followed by a 14-day depuration phase in clean water. Characterization of the exposure media revealed the presence of 26 pharmaceuticals while 5 pharmaceuticals including caffeine, diphenhydramine, diltiazem, carbamazepine, and ibuprofen were present in the organisms as early as 5 h from the start of the exposure. Liquid chromatography ultra-high resolution Orbitrap mass spectrometry was explored as a tool to identify and quantify phase II pharmaceutical metabolites in reclaimed water. The resulting data confirmed the presence of acetyl-sulfamethoxazole and sulfamethoxazole glucuronide in reclaimed water. To my knowledge, this is the first known report of sulfamethoxazole glucuronide surviving intact through wastewater treatment plants and occurring in environmental water samples. Finally, five bioaccumulative pharmaceuticals including caffeine, carbamazepine, diltiazem, diphenhydramine and ibuprofen detected in reclaimed water were investigated regarding the acute and chronic risks to aquatic organisms. The results indicated a low potential risk of carbamazepine even under the worst case exposure scenario. Given the dilution factors that affect environmental releases, the risk of exposure to carbamazepine will be even more reduced.

Orientador: Ney Carter do Carmo Borges / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T15:34:25Z (GMT). No. of bitstreams: 1 Moreira_RobertoFernandes_D.pdf: 2940817 bytes, checksum: 525d43271d9ecc3f57856c7a4f024a5d (MD5) Previous issue date: 2014 / Resumo: Na última década, a evolução dos aspectos técnicos da regulamentação brasileira na área de medicamentos, tendo como base princípios científicos, é inquestionável. A implantação das legislações contribuiu para o aprimoramento da fabricação e garantia de qualidade dos medicamentos no país, introduzindo conceitos tais como equivalência farmacêutica, biodisponibilidade e bioequivalência. O teste de bioequivalência é fundamental para garantir que dois medicamentos que comprovaram a equivalência farmacêutica apresentará o mesmo desempenho no organismo em relação à biodisponibilidade, expressa em termos da quantidade absorvida do fármaco, a partir da forma farmacêutica ministrada, e da velocidade do processo de absorção. Os procedimentos analíticos descritos neste trabalho estão em conformidade com os requisitos do FDA e da ANVISA para a quantificação de drogas em estudos farmacocinéticos em humanos. Neste trabalho, descrevemos o primeiro método desenvolvido para a quantificação de clorpromazina em plasma humano utilizando Cromatografia Líquida de Ultra Eficiência (CLUE) acoplado a um espectrômetro de massa triplo quadrupolo em tandem e electrospray em modo positivo (CLUE-ES(+)-EM/EM). O analito e o padrão interno (IS) foram extraídos do plasma humano pela técnica líquido-líquido com éter dietílico/diclorometano (70/30, V/V). A cromatografia foi conduzida isocraticamente num Aquity UPLC BEH C18 1,7 mm (50 mm x 2,1 mm di) operando a 40°C. A fase móvel foi uma mistura de 65% de água + 1% de ácido fórmico e 35% de acetonitrilo a uma taxa de fluxo de 0,5 mL/min. O limite de quantificação foi de 0,5ng/ml e uma curva de calibração linear 0,5-200ng/ml, mostrando precisão intra-ensaio de 2,4 a 5,8%, e precisão inter-ensaio foi de 3,6 a 9,9%. A exatidão intra-ensaio variou de 96,9 a 102,5%, enquanto a exatidão inter-ensaio variou de 94,1 a 100,3%. Este método de análise foi aplicado em um estudo de biodisponibilidade relativa, a fim de comparar uma formulação teste na dose de 100mg de clorpromazina contra uma formulação referência em 57 voluntários de ambos os sexos. Além disso, descrevemos o método analítico para quantificação de ondansetrona em plasma humano utilizando CLAE-EM/EM, associado ao menor tempo de análise cromatográfica descrita e baixo volume de plasma para extração do ativo. Amostras de plasma humano foram extraídas com éter metil-terc-butílico e analisadas por CLAE-ES-EM/EM. O limite de quantificação foi de 0,2ng/mL e o método foi linear no intervalo de 0,2-60ng/ml. A precisão intra-ensaio ficou entre 1,6 a 7,7%, enquanto que a precisão inter-ensaio variou de 2,1 a 5,1%. As exatidões intra-ensaio variaram de 97,5 a 108,2% e a exatidão inter-ensaio variaram de 97,3 a 107,0%. Este método analítico foi utilizado em um estudo de biodisponibilidade relativa de duas formulações farmacêuticas contendo 8 mg de ondansetrona cada em 25 voluntários saudáveis, usando, o delineamento cruzado em dois períodos. Finalmente, o método analítico para quantificação de imipramina utiliza CLUE-EM/EM, apresentando baixo limite de quantificação associado ao menor tempo de análise cromatográfica em comparação aos trabalhos descritos na literatura. A imipramina e o IS foram extraídos a partir de plasma humano utilizando éter dietílico/diclorometano (60/40, V/V) e analisadas por CLUE-ES+-EM/EM. A cromatografia foi realizada em modo isocrático em um CLUE BEH C18 1.7 Aquity One (100 mm x 2,1 mm di) operando a 40ºC. A fase móvel era composta de uma mistura de 65% de água, 1% de ácido fórmico e 35% de acetonitrilo bombeada a uma taxa de fluxo de 0,5mL/min. O limite de quantificação foi de 0,1ng/ml com linearidade no intervalo de 0,1 a 20ng/mL. O método mostrou precisão intra-ensaio de 0,8 a 5,8% e precisão inter-ensaio de 2,1 a 5,1%. As exatidões intra-ensaio variaram de 95,0 a 105,4%, enquanto a exatidão inter-ensaio variou de 98,2 a 108,2%. Este método de análise foi aplicada em um estudo de biodisponibilidade relativa entre uma formulação teste com 25mg de imipamine contra um comprimido da formulação referência em 35 voluntários de ambos os sexos. Este trabalho descreve três estudos de bioequivalência dos ativos clorpromazina, ondansetrona e imipramina, sendo cada um dos estudos com delineamento aberto, aleatorizado, cruzado de dois períodos. Uma vez que o IC de 90% para as razões de Cmax e ASC ficaram dentro do intervalo de 80-125% em todos os estudos, concluiu-se que as formulações em teste de clorpromazina, ondansetrona e imipramina são bioequivalentes às respectivas formulações de referência no que diz respeito tanto à taxa e extensão como de absorção / Abstract: In the last decade, the evolution of the technical aspects of the Brazilian regulations in the area of medications, based on scientific principles, is unquestionable. The implementation of the specific laws and regulations have contributed to the improvement of manufacturing and quality assurance of medicines in the country, introducing concepts such as pharmaceutical equivalence, bioequivalence and bioavailability. Bioequivalence testing is critical to ensure that the two medications that have proved pharmaceutical equivalence will have the same bioavailability in the body, expressed in terms of the amount of absorbed drug and the speed of absorption using the dosage form provided. Analytical procedures described in this work are in accordance with the requirements of the FDA and ANVISA for the quantitation of drugs in pharmacokinetic studies in humans. Here we describe the first method for the quantitation of chlorpromazine in human plasma using an ultra performance liquid chromatography (UPLC) coupled to an electrospray tandem triple quadrupole mass spectrometer in positive mode (UPLC-ES(+)-MS/MS). The analyte and the internal standard (IS) were extracted from human plasma by a liquid-liquid extraction with diethyl ether/dichloromethane (70/30, v/v) and chromatography was performed isocratically on an Aquity UPLC BEH C18 1.7 ?m (50 mm x 2.1 mm i.d.) operating at 40°C. The mobile phase was a mixture of 65% water+1% formic acid and 35% of acetonitrile at a flow-rate of 0.5 mL/min. The lowest concentration quantified was 0.5ng/mL and a linear calibration curve over the range 0.5-200 ng/mL was obtained, showing intra-assay precisions from 2.4 to 5.8%, and inter-assay precisions from 3.6 to 9.9%. The intra-assay accuracies ranged from 96.9 to 102.5%, while the inter-assay accuracies ranged from 94.1 to 100.3%. This analytical method was applied in a relative bioavailability study in order to compare a test chlorpromazine 100 mg simple dose formulation versus a reference in 57 volunteers of both sexes. The analytical method for quantification of ondansetron in human plasma described here offers advantages over previously reported using HPLC-MS/MS, associated with shorter chromatographic analysis described and low plasma volume for extracting active. Human plasma samples were extracted by liquid-liquid extraction (LLE) using methyl tert-butyl ether and analyzed by LC-ESI-MS/MS. The limit of quantification was 0.2?ng/mL and the method was linear in the range 0.2-60?ng/mL. The intra-assay precisions ranged from 1.6 to 7.7%, while inter-assay precisions ranged from 2.1 to 5.1%. The intra-assay accuracies ranged from 97.5 to 108.2%, and the inter-assay accuracies ranged from 97.3 to 107.0%. The analytical method was applied to evaluate the relative bioavailability of two pharmaceutical formulations containing 8?mg of ondansetron each in 25 healthy volunteers using a randomized, two-period crossover design. In addition, the analytical method for the quantification of imipramine in human plasma described here offers advantages over previously reported using UPLC-MS/MS, HPLC-MS/MS and HPLC-MS, with low limit of quantification associated with shorter chromatographic analysis described in the literature. The analyte and the IS were extracted from human plasma by a liquid¿liquid extraction with diethyl ether/dichloromethane (60/40, V/V) and analyzed by UPLC¿ES+-MS/MS. Chromatography was performed isocratically on an UPLC BEH C18 1.7 Aquity One (100 mm ×2.1 mm i.d.) operating at 40ºC. The mobile phase was a mixture of 65% water + 1% formic acid and 35% of acetonitrile at a flow-rate of 0.5 mL/min. The lowest concentration quantified was 0.1ng/mL and a linear calibration curve over the range 0.1¿20ng/mL was obtained, showing intra-assay precisions from 0.8 to 5.8%, and inter-assay precisions from 2.1 to 5.1%. The intra-assay accuracies ranged from 95.0 to 105.4%, while the inter-assay accuracies ranged from 98.2 to 108.2%. This analytical method was applied in a relative bioavailability study in order to compare a test imipamine 25 mg simple dose formulation versus a reference tablet in 35 volunteers of both sexes. The study was conducted in an open randomized two-period crossover design and with a fourteen days washout period. Since the 90% CI for ASC and Cmax ratios were within the range of 80-125% for all studies, it was concluded that the test formulations of chlorpromazine, imipramine and ondansetron are bioequivalent to the respective reference formulations with respect to both rate and extent of absorption / Doutorado / Clinica Medica / Doutor em Ciências

La angiogénesis y la neovascularización son procesos biológicos que tienen lugar en los tejidos y que están asociados al aumento de las demandas de oxígeno y nutrientes. En adultos normales estos procesos no suelen ocurrir. Sin embargo, en condiciones de enfermedad, como en inflamaciones o en el desarrollo de tumores, el VEGF (factor de crecimiento vascular endotelial, del inglés vascular endothelial growth factor), ls proteína señalizadora causante de la angiogénesis,está fuertemente expresada. En estas circunstancias se formas rápidamente nuevos vasos y capilares. Esta nueva red vascular es caótica y no presenta una estructura normal, especialmente en el caso de tumores. La cuantificación de la angiogénesis es esencial para evaluar el grado de agresividad de un tumor y la eficacia de los tratamientos. Es necesario desarrollar herramientas fiables y reproducibles que sean sensibles a cambios tempranos, lo cual puede permitir utilizar tratamientos más individualizados. En este sentido, el modelado farmacocinético de imágenes de perfusión por resonancia magnética (RM) es una valiosa herramienta para la evaluación de parámetros como la permeabilidad capilar, el coeficiente de extracción, el volumen intersiticial y el volumen vascular. / Sanz Requena, R. (2010). Methodological developments and clinical applications of pharmacokinetic models in contrast-enhanced magnetic resonance perfusion studies [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8422 / Palancia