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Increased-rate stability studies for St John's wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions
Dissertation (MSc (Pharmacology))--University of Pretoria, 2001.
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University of Pretoria
2013
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| _version_ | 1867613538904702976 |
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| access_status_str | Open Access |
| author2 | Eloff, Jacobus Nicolaas |
| author_browse | Eloff, Jacobus Nicolaas |
| author_facet | Eloff, Jacobus Nicolaas |
| collection | Thesis |
| dc_rights_str_mv | © 2001 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc (Pharmacology))--University of Pretoria, 2001. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/23083 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:37:44.900Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/23083 Increased-rate stability studies for St John's wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions Eloff, Jacobus Nicolaas upetd@up.ac.za Van Brummelen, R. Marais, Andre Materia medica vegetable Herbs therapeutic uses Ginkgo Kava plant Hypericum perforatum UCTD Dissertation (MSc (Pharmacology))--University of Pretoria, 2001. This was a chemical laboratory study. The main focus was to evaluate the chemical stability of Hypericum perforatum (St John's wort), Ginkgo biloba and Piper methysticum (Kava Kava) under unfavourable environmental conditions. Different dosage forms representing the same amount of active ingredients for each were used. Some of the dosage forms were self manufactured according to Good Manufacturing Practice. Samples of the dried powder of each plant was also exposed to a series of gamma¬radiation. Acetone was used as an extractant for all three plants, after evaluating and discarding the extraction method stipulated in the British Herbal Pharmacopoeia. Identification of the different plants were carried out by means of Thin Layer Chromatography. The in-house developed mobile phases EMW, BEA and CEF, showed better separation and visibility compared to the mobile phases used in the British Herbal Pharmacopoeia. The plates were sprayed with either vanillin or p-anisaldehide for optimal visualization of the separated compounds. After the specified period of 6-months, comparative TLC was performed on all samples. This was achieved for each plant by applying all samples stored at a specific condition i.e.25°C, on the same plate. The samples were stored at low temperature after exposure to the specific time interval. Quantitative analysis was performed by spectrophotometry, and high pressure liquid chromatography. The data obtained from these analytical methods, were used to evaluate the relative chemical stability of each dosage form. The relationship between the quantitative data and the qualitative changes in the TLC fingerprints, were compared, hoping to achieve a common pattern relating to the stability. The order of the reaction as well as the reaction rate constant (k) for each dosage form was calculated, except for kava kava. The shelf-life (too) was calculated using the analyzed data obtained by spectrophotometry or HPLC. The relevance of conventional pharmaceutical calculations in the prediction of shelf-life, by means of accelerated stability tests, was investigated for the possible application to herbal products. The effects of gamma radiation on the degradation of the chemical compounds present in each plant, was evaluated. After an evaluation of all the relevant data, it seemed that the tablet-dosage forms were equally effective regarding stability, compared to the capsules. Liquid extracts appeared to be less stable than the extract capsules. The extract capsules seemed to degrade more rapidly than the herbal tablets or herbal capsules. Exposure to low dose radiation (4.4 kGy) did not seem to have an influence on the stability. It was evident that some herbs were more sensitive to sunlight or heat than others. In general, all three of the chosen plants seemed to be relatively stable if stored in the specified conditions. It seemed valid for the shelf-life to be expressed as two years. Pharmacology unrestricted 2013-09-06T14:29:02Z 2006-03-13 2013-09-06T14:29:02Z 2001-09-01 2001 2006-03-10 Dissertation Marais, A 2001, Increased-rate stability studies for St John’s wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/23083 > H1170/ag http://hdl.handle.net/2263/23083 http://upetd.up.ac.za/thesis/available/etd-03102006-144159/ © 2001 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf application/pdf application/pdf application/pdf University of Pretoria |
| spellingShingle | Materia medica vegetable Herbs therapeutic uses Ginkgo Kava plant Hypericum perforatum UCTD Increased-rate stability studies for St John's wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions |
| title | Increased-rate stability studies for St John's wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions |
| title_full | Increased-rate stability studies for St John's wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions |
| title_fullStr | Increased-rate stability studies for St John's wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions |
| title_full_unstemmed | Increased-rate stability studies for St John's wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions |
| title_short | Increased-rate stability studies for St John's wort (Hypericum perforatum), Ginkgo biloba and Kava Kava (Piper methysticum) under unfavourable environmental conditions |
| title_sort | increased rate stability studies for st john s wort hypericum perforatum ginkgo biloba and kava kava piper methysticum under unfavourable environmental conditions |
| topic | Materia medica vegetable Herbs therapeutic uses Ginkgo Kava plant Hypericum perforatum UCTD |
| url | http://hdl.handle.net/2263/23083 http://upetd.up.ac.za/thesis/available/etd-03102006-144159/ |