by Ma Chin Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 129-131). / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- Theory --- p.4 / Chapter Chapter 3. --- The Retention Mechanism of Cyano-Bonded Stationary Phase for Some Basic Drugs in Polar Eluents / Chapter 3.1 --- Introduction --- p.18 / Chapter 3.2 --- Experimental / Chapter 3.2.1 --- Reagents --- p.20 / Chapter 3.2.2 --- Equipment --- p.21 / Chapter 3.2.3 --- Standard Preparation --- p.21 / Chapter 3.2.4 --- Procedures --- p.22 / Chapter 3.3 --- Results and Discussion / Chapter 3.3.1 --- Acetonitrile-Perchloric Acid Systems --- p.29 / Chapter 3.3.2 --- Acetonitrile-Perchlorate Salts Eluent Systems --- p.42 / Chapter 3.3.3 --- Retention and Acetonitrile Composition --- p.49 / Chapter 3.4 --- Conclusion --- p.54 / Chapter 3.5 --- References --- p.55 / Chapter Chapter 4. --- Detector Response / Chapter 4.1 --- Introduction --- p.56 / Chapter 4.2 --- Experimental / Chapter 4.2.1 --- Reagents and Equipment --- p.57 / Chapter 4.3 --- Results and Discussion / Chapter 4.3.1 --- "The Relationship between Peak Area, Peak Height, and Detector Response" --- p.58 / Chapter 4.3.2 --- Detector Response and Eluent Strength --- p.60 / Chapter 4.3.3 --- Detector Response and Flow Rate --- p.74 / Chapter 4.4 --- Conclusion --- p.77 / Chapter 4.5 --- References --- p.78 / Chapter Chapter 5. --- Determination of Benzhexol Hydrochloride and Ethambutol Hydrochloride tablets by HPLC / Chapter 5.1 --- Introduction --- p.79 / Chapter 5.2 --- Experimental / Chapter 5.2.1 --- Reagents --- p.84 / Chapter 5.2.2 --- Equipment --- p.85 / Chapter 5.2.3 --- Samples --- p.86 / Chapter 5.2.4 --- Preparation of Reagents and Standards --- p.88 / Chapter 5.2.5 --- Sample Preparation and Determination --- p.89 / Chapter 5.3 --- Results and Discussion / Chapter 5.3.1 --- Sample Treatment and Extraction of Active Ingredient(s) --- p.91 / Chapter 5.3.2 --- Explanation of Chromatograms --- p.92 / Chapter 5.3.3 --- Choice of Experimental Conditions --- p.96 / Chapter 5.3.4 --- Linear Dynamic Response --- p.102 / Chapter 5.3.5 --- Sensitivity --- p.102 / Chapter 5.3.6 --- Analysis Results --- p.103 / Chapter 5.3.7 --- Comparison of Results from the Methods --- p.106 / Chapter 5.3.8 --- Precision and Accuracy --- p.113 / Chapter 5.3.9 --- Effect of Methanol Content on the Chromatographic Behaviour in Analysing Benzhexol Hcl --- p.117 / Chapter 5.3.10 --- Discussion on the Pharmacopoeial Assay of Benzhexol HC1 Tablets --- p.120 / Chapter 5.3.11 --- Discussion on the Various Factors Influencing the Pharmacopoeial Assay of Ethambutol HC1 Tablets --- p.123 / Chapter 5.4 --- Conclusion --- p.128 / Chapter 5.5 --- References --- p.129 / Appendix --- p.132

by Chan, Kim Hung. / Thesis (M.Sc.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 76-89). / Abstract also in Chinese. / Chapter 1. --- INTRODUCION --- p.1 / Chapter 1.1 --- amino acid analysis by high performance liquid chromatography --- p.1 / Chapter 1.1.1 --- History and Development --- p.1 / Chapter 1.1.2 --- Separation mechanism --- p.2 / Chapter 1.1.3 --- Derivatization --- p.4 / Chapter 1.1.4 --- Dqproteinization --- p.8 / Chapter 1.1.5 --- Ion-exchange or Reversed-phase HPLC --- p.9 / Chapter 1.2 --- amino acid pattern in cancer patient --- p.11 / Chapter 1.2.1 --- Cancer cachexia --- p.11 / Chapter 1.2.2 --- Causes of cancer cachexia --- p.11 / Chapter 1.2.3 --- Cytokines --- p.12 / Chapter 1.2.4 --- Metabolic Alteration in cancer cachexia --- p.13 / Chapter 1.2.5 --- Amino Acid Studies --- p.14 / Chapter 1.3 --- methodology chosen --- p.19 / Chapter 1.4 --- patient sample chosen --- p.21 / Chapter 2. --- OBJECTIVES --- p.22 / Chapter 3. --- MATERIALS AND METHOD --- p.23 / Chapter 3.1 --- apparatus --- p.23 / Chapter 3.1.1 --- HPLC System --- p.23 / Chapter 3.1.2 --- Column --- p.23 / Chapter 3.1.3 --- Detector --- p.23 / Chapter 3.1.4 --- ChemStation --- p.24 / Chapter 3.2 --- reagents --- p.24 / Chapter 3.2.1 --- Reagent and Chemical source --- p.24 / Chapter 3.2.2 --- Mobile phase --- p.24 / Chapter 3.2.3 --- Derivatization Reagent --- p.25 / Chapter 3.2.4 --- Standard preparation --- p.26 / Chapter 3.2.5 --- Internal standard --- p.28 / Chapter 3.3 --- sample preparation --- p.28 / Chapter 3.4 --- chromatographic conditions --- p.29 / Chapter 3.4.1 --- Column Temperature --- p.29 / Chapter 3.4.2 --- Injector Program --- p.29 / Chapter 3.4.3 --- Time Table for gradient elution and flow program --- p.32 / Chapter 3.5.1 --- OP A and sample Ratio and Volume --- p.32 / Chapter 3.5.2 --- Derivatization Concentration --- p.33 / Chapter 3.5.3 --- Derivatization time --- p.33 / Chapter 3 6 --- analytical performance --- p.34 / Chapter 3.6.1 --- Linearity testing --- p.34 / Chapter 3.6.2 --- Recovery studies --- p.34 / Chapter 3.6.3 --- Precision --- p.34 / Chapter 3.6.4 --- Sample storage --- p.35 / Chapter 3.7 --- clinical sample studies --- p.35 / Chapter 3.8 --- statistical analysis --- p.36 / Chapter 4 --- RESULT --- p.37 / Chapter 4.1 --- chromatographic separation --- p.37 / Chapter 4.2 --- optimization --- p.40 / Chapter 4.2.1 --- OPA and sample Ratio and Volume --- p.40 / Chapter 4.2.2 --- Derivatization time --- p.43 / Chapter 4.2.3 --- OPA Concentration --- p.43 / Chapter 4.3 --- analytical performance --- p.46 / Chapter 4.3.1 --- Linearity --- p.46 / Chapter 4.3.2 --- Recovery studies --- p.46 / Chapter 4.3.3 --- Precision Studies --- p.50 / Chapter 4.3.4 --- Sample storage studies --- p.53 / Chapter 4.4 --- clinical sample study --- p.55 / Chapter 5. --- DISCUSSION --- p.64 / Chapter 5.1 --- analytical --- p.64 / Chapter 5.2 --- clinical --- p.71 / Chapter 5.2.1 --- Normal controls --- p.71 / Chapter 5.2.2 --- Colorectal Cancer --- p.71 / Chapter 5.2.3 --- Lung Cancer --- p.72 / Chapter 5.2.4 --- Nasopharyngeal Cancer --- p.73 / Chapter 5.2.5 --- Summary --- p.74 / Chapter 6. --- CONCLUSION --- p.75 / Chapter 7. --- REFERENCES --- p.75

>Magister Scientiae - MSc / Liposomes as a drug carrier in the pharmaceutical industry has gained currency since its discovery in 1965 by Bangham A. D. Liposomes have been shown to improve bioavailability as they can be delivered to target sites and possess sustained release properties which could be used to mitigate certain weaknesses associated with current diclofenac sodium eye drops. Diclofenac sodium (DNa) eye drop is a sterile Nonsteroidal Anti-inflammatory Drug (NSAID) with diclofenac sodium as its active ingredient. It is indicated for the lessening of ocular pain, prevention of miosis in eye operations, easing of postoperative inflammation and cystoids macular edema. The residence time of eye drops after application has been found to be 1-2 minutes as a result of continuous production of tears diluting the active ingredient, draining the eye drops into the nasolacrimal path, and eliminating it during blinking. As a result of the active ingredient not residing at the target site for the required duration, more frequent administration and medication is required and the risk of non-compliance is increased. Given the aforementioned potential of liposomes to redress the above weaknesses of current eye drops (dosage form) available for diclofenac sodium ophthalmic application, this study sought to encapsulate diclofenac sodium into liposomes for ophthalmic application. The main components of liposomes (cholesterol and phosphotidylcholine) and incubation time were set as the independent variables while percentage encapsulation, polydispersity index (PDI) and drug release profile constituted the dependent variable. Using analysis of variance (ANOVA) and t-test statistics, the interaction between the independent variables and their effect on the dependent variables were tested.

A azatioprina (AZA) é um imunossupressor utilizado no tratamento de doenças autoimunes como lúpus eritematoso sistêmico, doença de Crohn, doença inflamatória intestinal e contra a rejeição em transplantes de órgãos sólidos. Após mais de 40 anos de uso a AZA continua exercendo um papel central nos regimes imunomoduladores, devido ao fato de combinar eficácia, segurança e baixo custo. Sabe-se que a atividade da tiopurina metiltransferase pode determinar, pelo menos em parte, a eficácia clínica da AZA. Esta enzima apresenta polimorfismo genético co-dominante e a distribuição dos alelos variantes é significativamente diferente entre as populações. A grande variabilidade farmacocinética no metabolismo AZA justifica a sua monitorização terapêutica. Neste trabalho otimizou-se uma metodologia para a quantificação dos metabólitos da AZA, 6-TGN e 6-MMP, por cromatografia líquida de alta eficiência (HPLC/UV-Vis), utilizando-se um detector de ultravioleta-visível em um único comprimento de onda, após a amostra passar por uma desproteinização ácida simples e ser aquecida para a conversão dos metabólitos em suas respectivas bases livres. Os valores destes metabólitos foram determinados em uma população de 124 pacientes transplantados renais. Para adequarmos o processo às legislações locais e internacionais, foram seguidas orientações da Anvisa, FDA e CLSI. A separação foi realizada em coluna de fase reversa, sendo a fase móvel A fosfato de potássio e a fase móvel B metanol. A detecção da 6-TGN e da 6-MMP foi realizada em 342 m (UV-Vis). O estudo da linearidade da 6-TGN variou entre 0,30 e 89,71 mol/L e da 6-MMP entre 0,30 e 93,86 mol/L. As recuperações, de 95,08 a 100,80% para 6-TGN e 95,38 a 105,06% para 6-MMP. Os CV da repetibilidade, de 0,04 a 5,06%, enquanto os CV da reprodutibilidade de 4,88 a 12,73% para 6-TGN e 6-MMP. Para ambos os metabólitos o LD e o LQ foram de 0,30 mol/L e 0,13 mol/L. Os eritrócitos lavados e as amostras tratadas, prontas para a injeção no HPLC, foram armazenadas abaixo de -5°C até a análise. Nesta temperatura estiveram estáveis durante 8 semanas e 1 dia, respectivamente. Os valores das concentrações de 6-TGN e 6-MMP encontrados nas amostras dos pacientes variaram entre não detectável a 1569 mol/8 x 108 RBC (mediana de 200,50) e não detectável a 113057 mol/8 x 108 RBC (mediana de 5166), respectivamente. As correlações entre os níveis de 6-TGN ou 6-MMP e as variáveis sexo, tempo pós-transplante, número de transplantes e dosagem de AZA (mg/kg) foram examinadas em diferentes grupos. O método proposto apresenta boa relação custo-benefício, é simples, preciso e rápido na determinação das concentrações intraeritrocitárias de 6-TGN e 6-MMP em pacientes sob terapia com AZA. O método validado permite que o laboratório forneça dados farmacocinéticos úteis e precisos para o ajuste do tratamento do paciente e pode ser facilmente adaptado para a análise rotineira destes metabólitos. Os resultados das amostras dos pacientes estão de acordo com os encontrados em outros estudos, atestando a utilidade dessa ferramenta analítica no acompanhamento dos pacientes / Azathioprine (AZA) is an immunosuppressant used in autoimmune pathologies like lupus erythematosus, Chrons disease, inflammatory bowel disease and against rejection in solid organs transplant. After more than 40 years of use, AZA continues exerting a central role in immunomodulatory regimens, due to the fact that it combines effectiveness, safety and low cost. It is well known that thiopurine methyltransferase activity may determine, at least in part, the clinical efficacy of AZA therapy. This enzyme exhibits codominant genetic polymorphism and the distribution of these variant alleles differs significantly among populations. The considerable pharmacokinetic variability in AZA metabolism justify the therapeutic drug monitoring of this drug. In this work a methodology was improved to quantify the metabolites of AZA, 6-TGN and 6-MMP, by high performance liquid chromatography (HPLC/UV-Vis) with an ultraviolet-visible detector, using a single wavelength reading, following a simple acid deproteinization and heating to convert the metabolites into their respective free bases. The values of these metabolites were determined in a population of 124 renal transplant recipients. To adequate the process to international and local legislation, Anvisa, FDA and CLSI guidelines were followed. Separation was achieved on a reversed-phase column; mobile phase A potassium phosphate and mobile phase B methanol. Detection of 6-TGN and 6-MMP was performed at 342 m (UV-Vis). Assay linearity for 6-TGN ranged from 0.30 to 89.71 mol/L and from 0.30 to 93.86 mol/L for 6-MMP. The recoveries were 95.08, 97.76 and 100.80% for 6-TGN and 104.79, 95.38 and 105.06% for 6-MMP. Repeatability CV were 3.50, 5.06, 1.09 and 0.04, 0.35, 1.58%, while reproducibility CV were 8.65, 7.18, 8.44 and 12.73, 6.40, 4.88% for 6-TGN and 6-MMP, respectively. LOQ and LOD of 6-TNG and 6-MMP were respectively 0.30 mol/L and 0.13 mol/L for both metabolites. The washed erythrocytes and the samples treated and ready for injection into the HPLC system were stored below -5 °C until analysis, at this temperature the samples were stable for 8 weeks and for 1 day, respectively. 6-TGN and 6-MMP patient analysis values ranged from non detectable to 1569 mol/8 x 108 RBC (median of 200.50) and non detectable to 113057 mol/8 x 108 RBC (median of 5166), respectively. The correlations between 6-TGN or 6-MMP levels and variables sex, time post-transplant, number of transplants and AZA dosage (mg/kg) were examined in different groups. The proposed HPLC method has a good cost-benefit ratio, is straightforward, precise, accurate and fast at the determining 6-TGN and 6-MMP concentrations in red blood cells of patients under AZA therapy. The validated method is good enough to enable the laboratory to routinely provide useful and accurate pharmacokinetic data in time to adjust patient regimens. It can be easily adopted for routine analysis of these drug metabolites. The results of patient samples are in agreement with others studies, thus certifying the usefulness of this analytical tool in monitoring of patients

Purpose:Development of a stability-indicating high-performance liquid chromatography (HPLC) method for pyrimethamine analysis, with subsequent application of that method to assess the 90-day stability of a pyrimethamine suspension compounded from bulk USP-grade pyrimethamine powder, is described. Methods:A stability-indicating method of HPLC with ultraviolet detection specific to pyrimethamine was developed according to pharmacopeial recommendations and validated. The method was applied to investigate the stability of a 2-mg/mL pyrimethamine suspension in a vehicle consisting of Ora-Plus and Ora-Sweet (Perrigo) over a period of 90 days. Three replicate test preparations were stored at room temperature or refrigerated at 4.3–5.2 °C, and samples were analyzed in duplicate immediately after preparation and on study days 1, 2, 4, 7, 10, 14, 21, 30, 48, 60, 75, and 90. Results:The 2-mg/mL suspension of pyrimethamine in Ora-Plus and Ora-Sweet retained 90–110% of the labeled potency to 90 days at both temperature ranges. However, color changes in the samples stored at room temperature observed at day 60 indicated that a beyond-use date less than 90 days from the preparation date should be specified when the suspension is to be stored at room temperature. Conclusion:The study demonstrated that USP-grade pyrimethamine powder can be formulated as a 2-mg/mL suspension in a vehicle of Ora-Plus and Ora-Sweet and is stable when stored at room temperature and when refrigerated, in amber plastic bottles, for 48 and 90 days, respectively.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2002. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning) Linköping : Univ., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 4 uppsatser.