1. Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa
2. Department of Chemistry and Polymer Science, Faculty of Science, Stellenbosch University, De Beers Street, Stellenbosch 7600, South Africa