published_or_final_version / Community Medicine / Master / Master of Public Health

The World Health Organization estimates that 4 billion people use herbal medicine for some aspect of primary health care. These herbal products are however mostly used without the necessary clinical trial done to prove their pharmacological activities and, therefore, their quality, efficacy and safety. It was the objective of this study to review the current international guidelines for the evaluation of herbal medicine / to gain a perspective on the number, type and quality of clinical trials that have been done on herbal medicine and to adopt a set of guidelines that could be used to conduct trial on a traditional herbal medicine used in South Africa. To verify these guidelines, a protocol for a clinical trial was drafted and submitted for approval to the regulatory and ethical authorities in South Africa.

The World Health Organization estimates that 4 billion people use herbal medicine for some aspect of primary health care. These herbal products are however mostly used without the necessary clinical trial done to prove their pharmacological activities and, therefore, their quality, efficacy and safety. It was the objective of this study to review the current international guidelines for the evaluation of herbal medicine / to gain a perspective on the number, type and quality of clinical trials that have been done on herbal medicine and to adopt a set of guidelines that could be used to conduct trial on a traditional herbal medicine used in South Africa. To verify these guidelines, a protocol for a clinical trial was drafted and submitted for approval to the regulatory and ethical authorities in South Africa.

Magister Pharmaceuticae - MPharm / The World Health Organization estimates that 4 billion people use herbal medicine for some aspect of primary health care. These herbal products are however mostly used without the necessary clinical trial done to prove their pharmacological activities and, therefore, their quality, efficacy and safety. It was the objective of this study to review the current international guidelines for the evaluation of herbal medicine; to gain a perspective on the number, type and quality of clinical trials that have been done on herbal medicine and to adopt a set of guidelines that could be used to conduct trial on a traditional herbal medicine used in South Africa. To verify these guidelines, a protocol for a clinical trial was drafted and submitted for approval to the regulatory and ethical authorities in South Africa. / South Africa

Accelerating regulatory science has become an urgent task due to the ongoing emergence of novel and highly complex diseases, such as coronaviruses and mpox, and the growing real-world evidence and precision medicine paradigms. In research and development, achieving this goal requires the formulation and implementation of innovative clinical trial designs and statistical approaches. Further efforts are needed to devise robust strategies toward expediting the evaluation of drugs and other medical products, which will help to quicken the delivery of safe and effective treatments to individuals in need. One pioneering concept that has greatly contributed to speeding up product assessment is the application of pre-specified adaptations in clinical trials. Adaptive techniques (like early dose or treatment selection and sample size recalibration) are based on participant data collected during the trial, where investigators/sponsors are able to learn from the study population and adjust trial characteristics accordingly without diminishing the integrity of the study. However, adaptations must be employed cautiously; it is essential to ensure that they are both clinically reasonable and statistically sound (in the sense that they will not inflate the nominal type I error rate). The evolution of seamless trial designs has also propelled drug/medical product evaluation. For instance, seamless trials that combine a phase II study (e.g., using a biomarker or short-term intermediate endpoint for early dose or treatment selection) and a phase III study (e.g., using a definitive endpoint for confirming efficacy) have become very popular in practice due to their flexibility and shorter duration compared to running separate studies. In phase II/III seamless trials, a correlation is usually pre-specified between the intermediate and definitive endpoints in order to bridge the phase II and phase III studies and accomplish the overall aims of the intended trial. However, this can be difficult to quantify, especially when the endpoints are non-continuous. An inappropriate or unsubstantiated enumeration of this correlation can yield flawed results and thus misguide approval and labeling decisions, leading to potentially serious consequences. To avert this issue, a three-stage phase II/III transitional seamless trial design was constructed that does not demand prior knowledge of the correlation between the intermediate and definitive endpoints. The design also allows for interim sample size re-estimation according to the accrued intermediate endpoint data. The utility and validity of the design, with and without sample size adaptation, were considered for different types of endpoints. For each, theoretical proofs establish that the design can control the nominal type I error rate while still reaching the targeted power, and simulations reinforce these findings. Therefore, the design exhibits promise in precipitating the assessment of experimental interventions in a wide range of therapeutic areas. This dissertation is organized as follows. First, Chapter 1 presents (1) an introduction to the drug/medical product evaluation process, (2) an overview of adaptive techniques used in clinical trials, (3) a description of seamless trial designs, including a real-world example to demonstrate how they can be applied in different data situations, (4) the research goals, and (5) a display of the proposed three-stage phase II/III transitional seamless trial design and its workflow. Chapters 2-5 lay out the models and procedures for the proposed design when using a continuous intermediate endpoint and a continuous definitive endpoint, a binary intermediate endpoint and a continuous definitive endpoint, and a binary intermediate endpoint and a time-to-event definitive endpoint in the presence and absence of censored observations. This is proceeded by statistical justification and supporting simulations for each procedure. As some authors remain skeptical toward the use of adaptations in clinical trials, Chapter 6 counters an argument posed in the literature. In closing, Chapter 7 summarizes the work and its limitations and provides several additional considerations toward enhancing the proposed design and its generalizability.

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Clinical and forensic toxicology analysts rely heavily in their daily tests on the analysis of the conventional samples (blood and urine). However, these specimens are limited in the time scale they reflect with regard to drug intake history and also in terms of drug stability within the matrices. Alternative matrices such as hair, oral fluids and dried blood spots (DBS) provide new horizons and new opportunities. Drugs incorporated within hair are very stable. Hair also provides a very long detection window, for at least one year, if not a lot longer. Oral fluids on the other hand are non-intrusive, easy to collect and much cleaner sample matrix than blood or urine. DBS also offer great drug stability, are easy to collect, faster to analyse and suitable for automated analysis. However, a number of studies are needed to assess the limits of these alternative samples in terms of the correlation of their results with the results of conventional samples and with regard to drug stability. Such studies will enable a more reliable and confident interpretation of results obtained from these matrices especially for medico-legal purposes. The main aims of this research were: to develop and validate analytical methods for detection and quantitation of drugs of use and abuse in hair, oral fluids, blood and DBS samples, to investigate the correlation between dose and drug concentration in hair, blood and oral fluids after controlled chronic drug administration, to investigate the stability of anti-psychotic drugs in DBS (from patients) stored under different conditions and the effect of addition of preservative, and to investigate the alcohol intake prevalence among Kuwaiti drug addicts and correlate these results with selfreported intake. As the majority of drugs were basic, an extraction method based on methanolic incubation was developed for detection of basic/weak basic drugs in hair. It was compared to alkaline digestion (with NaOH) followed by liquid-liquid extraction (LLE). Detection was achieved by LC-MS/MS (Sciex2000) after separation on a C18 column. When applying both methods on positive authentic hair samples the results showed that the methanolic method was capable of extracting most basic drugs in hair but only partially, while the alkaline digestion method was found to degrade V some unstable drugs like sulpiride, but was capable of fully extracting the alkaline stable drugs such as quetiapine. After development and validation of the LLE-LC-MS(Exactive) method for the analysis of anti-psychotics in blood, oral fluids and hair, an investigation was carried out on the correlation pattern between trough concentrations in those three matrices. The most significant correlation coefficients (r) found were those between blood and hair concentrations, procyclidine r=0.83 (18 subjects p=<0.001), risperidone r=0.96 (14 subjects p=<0.001), haloperidol r=0.90 (10 subjects p=<0.001), OH-risperidone r=0.24 (13 subjects p=>0.44), quetiapine r=0.28 (14 subjects p=>0.33) and chlorprothixene r=0.32 (13 subjects p=>0.32). Among the interesting results was the strong correlation found between drugs half-lives and the mean ratio of hair concentration/dose (r=0.96, p=<0.003). The stability of anti-pyschotics in DBS from patients’ samples was assessed by storing them at four different temperatures (25, 4, -20 and -80°C) with and without prior impregnation of the DBS cards with sodium fluoride. After development and validation of the LLE-LC-MS method, samples were analysed at days 0, 45, 90 and 180. Results showed good stability of all the compounds (procyclidine, quetiapine, risperidone, OH-risperidone, chlorprothixene and haloperidol) in all the different storage conditions and no significant increase or decrease in drug concentrations with sodium fluoride impregnation. Finally, after trials with five different HPLC columns, two SPE cartridges, two LLE extraction procedures and two mass spectrometer instruments, a method was developed and validated for the detection and quantitation of alcohol’s minor and specific metabolite in hair, ethyl glucuronide (EtG). The method has a limit of detection (LOD) of 3pg/mg and lower limit of quantitation (LLOQ) of 9pg/mg. This method was applied to 59 hair samples from patients at a general addiction centre and alcohol prevalence was investigated and its correlation with self-reported use was investigated.

Methadone is currently the most widely used agent to manage opioid dependence, but clinical experience has highlighted some limitations with its use. In particular, a relatively high proportion of patients complain of breakthrough withdrawal symptoms ( non - holding ) at apparently adequate methadone doses. Levo - alpha - acetylmethadol ( LAAM ) is a long acting opioid that is likely to benefit methadone non - holders ; however, relatively little is known about its pharmacology at steady state. The primary aim of this thesis was to evaluate LAAM as an alternative maintenance pharmacotherapy to methadone for the treatment of non - holders ; subsidiary aims were to elucidate the pharmacodynamics and pharmacokinetics of LAAM and its active metabolites ( nor - and dinor - LAAM ), and to examine the in vitro activity of LAAM, nor - and dinor - LAAM. Sixteen methadone maintenance patients ( non - holders = 8 ) were recruited to participate in a randomised, crossover trial of LAAM and methadone. At steady state there were two testing sessions ( 24 h for methadone and 48 h for LAAM ) that featured the concurrent measurement of plasma drug concentrations and both subjective and physiological indices of opioid effect. Cognitive and psychomotor functions were also assessed once during each inter - dosing interval study. Ten age - and gender - matched controls were also tested. The peak magnitude of methadone ' s and LAAM ' s effects were similar. Compared to methadone, LAAM was associated with more stable and less severe withdrawal and mood disturbance. The general pattern of symptom complaints and cognitive function was similar for both drugs. Severity of mood disturbance and withdrawal was similar in holders on methadone and LAAM, but was greater in non - holders when they were taking methadone than LAAM. In comparison to plasma ( R ) - ( - ) methadone, plasma nor - and dinor - LAAM concentrations fluctuated little over the dosing interval. Furthermore, nor - and dinor - LAAM were both more potent in the guinea - pig ileum bioassay, and had greater affinity for mu opioid receptors in receptor binding studies, than LAAM. In conclusion, LAAM converted methadone non - holders into LAAM holders. It is proposed that it is the relatively flat plasma concentration - time profile for nor - and dinor - LAAM that confer stability of opioid effect, minimising withdrawal. Therefore, LAAM may have a role in selected patients, whose response to methadone is suboptimal. / Thesis (Ph.D.)--School of Medical Sciences, 2006.

Colchicine and paclitaxel are two common drugs used in chemotherapy to halt tumor growth. In the present study IAR 20 cells were treated for 24 and 48 hr with colchicine and paclitaxel alone, in combination or no drug which served as a control. Through the use of Western blotting, we determined that the treatments affected expression due of several proteins including bcl-2, bax, p53 and caspase-8. The changes observed in protein expression due to the treatments correlated to the photomicrographs of the cells in culture and cell viability, indicating that the drugs were activating and initiating apoptosis. Interestingly, morphological changes such as membrane blebbing and cell swelling (indicators of apoptosis) were observed in the treated cultures and even more important the combined treatment yielded both changes in morphology. Also, activity assays were performed to study the effects the treatments had on the activities of SAPK/JNK and caspase-3, known activators of apoptosis. High activities of SAPK/JNK and caspase-3 in 48 hr treatments directly influenced cell viability in that the treatments with the highest activities yielded the lowest cell numbers, indicating that apoptosis was occurring. Based on these findings it was concluded that combined treatments of colchicine and paclitaxel are not advantageous in hepatocytes and could provide some insight into the treatment of liver cancer. Additionally, it appeared the drugs were initiating apoptosis in a p53 independent manner. / Department of Biology

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