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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Developing a practical methodology for Chinese medicine research: approach, challenges and solutions. / CUHK electronic theses & dissertations collection

January 2010 (has links)
Chemical analyses, biological assays, and animal experiments provide important fundamental information of Traditional Chinese Medicine. In modern biomedical research, they should also be necessary prerequisites for clinical trials. A Chinese herbal formula, no matter how effective and safe in the pre-clinical studies, cannot be assumed clinically valid. No marketing approval should be granted without clinical studies. Thus, clinical trial plays a decisive role in the research and development of Traditional Chinese Medicine. Currently the highest level of efficacy evidence is obtained from randomized controlled clinical trial. Thousands of years of traditional use can provide us with valuable guidelines to the selection, preparation and application of herbal formulations. To be accepted as viable alternatives to western medicine, the rigorous methods of scientific and clinical validations must be applied. / In conclusion, the methodology of Chinese medicine research needs to improve. One practical way is to apply the efficacy-driven approach through the following steps: i) getting a simple herbal formula to try solving a difficult clinical problem and start an evidence-based clinical trial using methodology acceptable to current standard clinical trials i.e. randomized, placebo-controlled; ii) parallel laboratory experiments to understand the mode of action should be done; and; iii) making sure that the quality of herbs and their extracts are of the best standard. A promising item shown in the clinical trial and laboratory experiments would deserve more pharmacological investigations before considering marketing. (Abstract shortened by UMI.) / The distinctiveness of Chinese medicine is manifested in the diversity and the complexity of its components, the instability of its quantity, the fuzziness of its action mechanism, and the uncontrollability of its producing process. Traditional Chinese herbal formulae are usually formed by more than one plants, animal or mineral items. The composition is extremely complex. The efficacy thus can hardly be guaranteed. The methods of harvesting, drying, storage, transportation, and processing of plant material influence the efficacy and safety. The consistent efficacy, therefore, can hardly be guaranteed. For thousands of years, it has been observed by clinical practice that Traditional Chinese Medicine (TCM) has a rich scientific connotation and has developed a unique healthcare system. However, variable sources of raw materials, unknown active ingredients, difficulties in quality control, lack of safety evaluation, unclear mechanism of action, etc., all these factors constitute major challenges in modernization of TCM. / The effect of Traditional Chinese Medicine (TCM) may be characterized by its chemical compounds, which are also the active ingredients. The reproducibility and the stability of the active ingredients are the foundation to ensure the efficacy of TCM. The safety and efficacy of TCM is evaluated through its pharmacological effects and in clinical studies. Many Chinese herbal medicines have a long history of traditional use. However, most of them are of unproven efficacy by today's standard. Well-designed randomized controlled trials and comprehensive pre-clinical studies are not known. Although the lack of qualified evidence does not mean that Chinese herbal medicines lack efficacy or are unsafe, properly designed experimental and clinical investigations should still be done today. There is a need to scientifically prove and clinically validate its safety and efficacy through chemical standardization, biological assays, and clinical trials. / The general perception that herbal drugs are very safe and free from side effects is not true. Little do they know in the modern conditions, that the current herbs used for preparation of traditional Chinese medicine have been very different as compared with the ancient herbs in planting, extracting, producing, storage, application, dose level and the duration of clinical use. The active ingredients of herbal formula are higher after extracting with modern scientific methods; and the toxicity may also be correspondingly higher. The potential side effects after long-term use should not be overlooked. / The purpose of the research is to develop a practical methodology to obtain convincing evidences in quality, safety and efficacy of Chinese Medicine. When we use evidence-based research methodology to prove the quality, safety and efficacy, we are facing many challenges. / The quality control of Chinese herbal medicine is a systematic procedure. The initial critical step is to standardize the starting raw herbs, for knowing the exact species and subspecies, the ideal growing location, environmental conditions, harvesting methods, and storage conditions etc., i.e., following Good Agriculture Practice (GAP) to ensure the quality of the raw materials. The second step is to standardize the processing methods of the raw herbs. The third step is to standardize the preparation procedure of the final products according to the requirements of Good Manufacture Practice (GMP) guideline. The fourth step is to qualitatively and/or quantitatively evaluate the quality of the TCM medication based on one or more selected chemical markers. / by Cheng, King Fai. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Text in English with some Chinese characters; abstract and appendixes 3-5 also in Chinese.
2

Development and in-vitro evaluation of peroral and buccoadhesive formulations for biologically active crude oil extracted from Ligusticum chuanxiong, a traditional Chinese medicine. / CUHK electronic theses & dissertations collection

January 2005 (has links)
differential scanning calorimetric profile and the generation of much less intense and broader peaks in the powder X-ray diffraction pattern compared to beta-CD. FTIR analysis revealed significant physical interactions between CX oil and beta-CD in the granules, possibly due to complexation. Results from phase solubility measurements and proton nuclear magnetic resonance ( 1H-NMR) analysis of pure 3-butylidenephthalide (3-BDPH), a representative CX component, lend some support for the formation of a 1:1 stoichiometric inclusion complex between 3-BDPH and beta-CD. / Rhizoma chuanxiong (CX), the dried rhizome of Ligusticum Chuangxiong Hort. (Umbelliferae), has been extensively used in mainland China as a traditional herbal medicine for treating cardio-/cerebrovascular diseases and gynecological disorders. However, the active components in CX, which are predominantly essential oils, generally exhibit poor stability (mostly photo-oxidation), high volatility, low aqueous solubility, and extensive gut/hepatic metabolism, all of which can significantly reduce their oral bioavailability and therapeutic efficacy. The present project has investigated the feasibility of utilizing three formulation approaches to circumvent the aforementioned problems associated with the peroral delivery of CX (as crude oil mixture or individual components). / The first approach involved inclusion of CX oil in beta-cyclodextrin (beta-CD) as solid granules using a coprecipitation method optimized with the aid of an orthogonal study design. The resulting CX oil granules were colorless and odorless with a median particle size of 11.38mum; were stable to heat, light and moisture, and readily soluble in simulated gastric and intestinal fluids. The granules were largely amorphous, as evidenced by an absence of the melting endotherm for beta-CD in the formulation could be largely explicated by the complexation behavior and hydration properties of the two polymers blended in different weight percentages, as substantiated by turbidity measurement, viscosity determination and FTIR analysis of the pure polymer mixtures as well as swelling measurement of the formulated tablets. The sustained release behavior of 3-BDPH from the tablet was dependent on the relative proportion of the two polymers present, and could be similarly explained by the changes in hydration and complexation behavior of the polymers during the penetration of aqueous fluid into the tablet matrix. / The second approach involved incorporation of CX oil into surfactant micelles and liquid crystals as a self-emulsifying drug delivery system (SEDDS). An optimal formulation was developed through a judicial choice of excipients (lipids and surfactants/cosurfactant) and their proper combination in the correct proportions, as determined by the spontaneity of the emulsification process and the change in emulsion droplet size. The formulation was readily dispersible in water upon mild agitation, free from unpleasant odor, and stable in soft gelatin capsules for a storage period of at least 12 months under ambient condition. The optimal utilization of the lipid and surfactant blends in defined proportions in the formulation was further substantiated by interfacial tension determination and equilibrium phase analysis. / The third approach involved formulation of 3-BDPH (or crude CX oil) into a sustained-release buccoadhesive tablet, based on a systematic evaluation of the adhesive properties of two polymers (Carbopol 974P and hydroxypropyl methylcellulose K4M) used in the formulation. The adhesive properties of the formulation could be largely explicated by the complexation behavior and hydration properties of the two polymers blended in different weight percentages, as substantiated by turbidity measurement, viscosity determination and FTIR analysis of the pure polymer mixtures as well as swelling measurement of the formulated tablets. The sustained release behavior of 3-BDPH from the tablet was dependent on the relative proportion of the two polymers present, and could be similarly explained by the changes in hydration and complexation behavior of the polymers during the penetration of aqueous fluid into the tablet matrix. / Gao Yuan. / "April 2005." / Adviser: Albert H. L. Chow. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1585. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 193-223). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

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