Doctoral Degrees (Pharmaceutical Sciences)
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Browsing Doctoral Degrees (Pharmaceutical Sciences) by Author "Dangor, Cassim Mahomed."
Item Bioavailability studies on various dosage forms of the anorectic, diethylpropion hydrochloride.(1984) Dangor, Cassim Mahomed.; Veltman, A. M.The stereo-chemistry, structure activity relationships and the metabolism of the anorectic drug, diethylpropion hydrochloride, have been reviewed briefly, together with the analytical methods for the determination of this drug and its metabolites in biological fluids. In addition, the physico-chemical properties, mode of action, pharmacology and uses of the metabolites have been presented. A comprehensive review on general principles of salivary excretion of drugs and their therapeutic drug monitoring in saliva with relevant published data on saliva/plasma drug concentration relationships has been outlined. Sensitive and specific assay procedures, based on gas-liquid chromatography for the identification, separation and determination of diethylpropion and its two major metabolites i.e. ethylaminopropiophenone (11) and diethylnorpseudoephedrine (IV) in aqueous and biological fluids, have been developed. These methods were used to study the urinary excreUon as well as saliva and plasma levels of the two major metabolites and, where possible, the unchanged drug, in man. Sustained release pellets with diffusion rate-controlled membranes were employed to control the rate of input into the body by oral or rectal route of administration. Urinary excretion data and plasma levels of metabolites 11 and IV in volunteers, where the urine was controlled at an acidic pH, were used for the evaluation of the bioavailabilities of different dosage forms of diethylpropion hydrochloride. The concentrations of metabolites 11 and IV were also measured in saliva and in plasma after administration of the drug in different doses and dosage forms: relationships between saliva and plasma concentrations (S/P) and between urinary excretion rates and plasma concentrations (U/P) were developed for each of the two metabolites during plateau levels after oral administration of the sustained release pellets (Lot R 7773). The potential use of salivary excretion of the metabolites as an index to monitor their plasma levels and bioavailabilities, was examined. The distinct advantage of using a subdivided controlled release system (i. .e. sustained release pellets) to a single unit sustained release tablet (erosion-core type) in relation to influence of the physical presence of food on the rate and extent of absorption has been demons t rated . It was found that the route of administration (oral or rectal) did not significantly affect the bioavailability of the sustained release pellets. The study also involved the investigation of the release of the drug from the pellets. Because the release control step was diffusion, no significant influences on dissolution rates were observed with the use of different dissolution test models and agitation intensities. The influence of the concentration and composition (presence of cations viz. Na+ and K+ i~r anions viz . phosphate and borate) of the dissolution medium on the release of the drug from sustained release pellets, was also studied. Any potential changes in the dissolution pattern on storage of the pellets under different conditions (4°C, room temperature and 37°C) ovrr, a period of at least one year, were investigated. The in vitro and in vivo correlations of two lots of sustained release pellets, each exhibiting different dissolution profiles, and administered rectally and orally, were developed: the in vitro data on the free drug were related to the sum of the urinary excretion data of metabolites II and IV. An attempt to use an empirical approach to predict urinary excretion rate profiles of metabolite II after oral administration of the sustained release pellets, was promising; the calculated profiles were reasonably comparable with those of in vivo studies. However, the complete validity of such equations needs further investigations.Item An investigation of the antidiabetic herbal remedies used by traditional healers in Northern KwaZulu-Natal and their effect on blood glucose levels.(1998) Ziqubu-Page, Thembelihle Thandekile.; Chetty, Manoranjenni.; Makubalo, L. E.; Dangor, Cassim Mahomed.This research study undertook to investigate and evaluate for efficacy and safety, the herbal remedies used for treating Diabetes mellitus in northern KwaZulu-Natal. In addition, it sought to gain knowledge and better understanding of traditional healing systems and the medicinal use of the natural flora. During the process of assimilating the desired information, the epidemiological and socio-economic factors which determine the form of medicine chosen by rural people in the region, were quantified. Both aspects of explanatory studies i.e. experimental and observational were used. Firstly, to evaluate the safety of the two herbal remedies, laboratory animals were given an oral dose of the herbal medicine and observed for a period of 14 days. Efficacy was assessed by treating Streptozotocin-induced diabetic rats with the herbal remedies and comparing their effect on blood glucose with that of a conventional sulphonylurea. The second part of the study was observational and it involved monitoring human subjects (patients) for twelve months, who were already taking the herbal preparations (n=56) and comparing their prognoses with that of a group taking conventional medicine (n=97). A third group using both types of medicine (n=42) was included as control measure for a possible confounding factor. Main outcome measures; Both subjective and objective measures of the perceived health of the diabetic patients were measured, as well as the determinants of using traditional medicine versus conventional medicine. The battery of toxicity tests which utilises behavioural and functional observations of the laboratory animals, yielded no signs of toxicity or abnormal behaviour. The histopathological examination results of the sample organs from the treated rats also revealed no signs of abnormality that could be attributed to the herbal remedies tested. There was no sex variation recorded in the response. The first HP tested (HP-1) demonstrated minimal hypoglycaemic effect whereas HP-2 significantly lowered the blood glucose of the streptozotocin-induced diabetic rats by an average of 59%. This was comparable to the conventional medicine (Glibenclamide) used in the experiment. After 12 months of follow-up, 93 % of traditional medicine users (n=56) were convinced that their blood sugar was controlled because of the traditional remedy they were using. The proportion of diabetic cases who used conventional medicine were no better off than those who used traditional medicine or vice versa. Health status and the financial situation (income) of the respondents greatly influenced their choice for diabetic treatment. The herbal remedies that were investigated were non-toxic and safe for use and internal consumption. One preparation demonstrated a significant hypoglycaemic effect, which was comparable to the conventional allopathic medicine used in treating Diabetes mellitus. This study should serve as a springboard to encourage more pharmacological evaluation of herbal medicines.