The Clinical PK Laboratory proudly congratulates Dr Buyisile Goodnature Mkhize, Dr Precious Ngwalero Katundu, Dr Yashara Ryan, and Dr Gerard Aime Kenfack Teponnou on the successful completion of their PhD degrees, conferred on 31 March 2026. Supervised by Professor Lubbe Wiesner, their research represents significant contributions to clinical pharmacology, with a particular focus on tuberculosis pharmacotherapy, pharmacokinetics, and bioanalytical innovation.

Dr Buyisile Goodnature Mkhize’s thesis, “Exposure of drug-resistant tuberculosis drugs in breast milk,” focused on developing and validating bioanalytical assays to quantify second-line anti-tuberculosis drugs in breast milk. Her work provides important insights into drug exposure in breastfed infants and supports safer treatment strategies for lactating mothers with drug-resistant tuberculosis.

Dr Precious Ngwalero Katundu’s thesis, “Investigating the relationship between plasma and intracellular concentrations of bedaquiline and its metabolite N-desmethyl bedaquiline (M2) in drug-resistant TB patients with and without HIV infection in South Africa,” explored intracellular pharmacokinetics of bedaquiline and M2, generating novel insights into drug distribution at the site of infection and its relationship to plasma exposure.

Dr Yashara Ryan’s thesis, “4β-hydroxycholesterol-to-cholesterol ratio as an endogenous biomarker in human plasma to determine treatment effects of induction and inhibition of CYP3A4 enzyme activity,” reported the development of a validated bioanalytical method and demonstrated the utility of endogenous biomarkers in assessing enzyme activity and drug–drug interactions.

Dr Gerard Aime Kenfack Teponnou’s thesis, “Development of novel bioanalytical assays and an objective adherence measure of key second-line tuberculosis drugs,” centred on the development of a multiplex assay using dried blood spots, enabling more accessible and cost-effective therapeutic drug monitoring and adherence assessment in clinical settings.

We congratulate our graduates on this outstanding achievement and wish them all the best for the future!