Browsing by Author "Aucamp, Marique"

Now showing 1 - 7 of 7
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    Design of a thermoresponsive hydrogel for enhanced intratumoral permeation of a chemotherapeutic agent in oral squamous cell carcinoma
    (University of the Western Cape, 2023) Tanga, Sandrine; Aucamp, Marique
    Introduction: Oral squamous cell carcinoma is the most common and aggressive cancer occurring in the oral cavity. Intravenous chemotherapy remains a pivotal part of treatment for the disease; however, these drugs cause debilitating systemic side effects and are unable to permeate into the deep compact layers of tumorous tissue cells. Herein, the intratumoral delivery of doxorubicin using a novel hydrogel blend, of chitosan/k-carrageenan and PluronicTM F127, for a rapid solution-to-gel thermoresponsive transition at 37 °C is proposed to achieve tumour-specific delivery and controlled drug release. For enhanced permeation, a novel monoterpene – limonene with high lipophilicity and anti-cancer effect is combined with the hydrogel system.
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    An investigation into combined amorphous form of sufadoxine, pyrimethamine and azithromycin
    (University of Western Cape, 2021) Okello, Geoffrey; Aucamp, Marique
    Malaria remains one of the top mortality causes in the sub-Saharan African region, especially among pregnant women and infants. Despite several measures being implemented within the affected areas such as the use of treated mosquito nets, sulfadoxine and pyrimethamine (SULPYR) as an intermittent preventive treatment (IPTp-SP) is still considered the standard prophylactic regimen for pregnant women. Recently, the WHO increased the regimen of IPTp- SP from three to four doses on a monthly interval, this recommendation poses a potential risk of toxicity and resistance to the drugs. An improvement towards this challenge is under clinical trial and consists of the inclusion of azithromycin (AZI), a macrolide antibiotic, to the current IPTp-SP treatment regimen. This will not only aid in the prophylaxis of malaria in pregnant women but will also assist in other pregnancy related infections. All three these drugs exhibit poor aqueous solubility; requiring high concentrations for oral administration to achieve therapeutic plasma concentrations.
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    Investigation of suitable microencapsulation techniques in the preformulation of selected antiretroviral drugs
    (University of the Western Cape, 2022) Okafor, Nnamdi Ikemefuna; Aucamp, Marique
    Background: The use of antiretroviral drugs (ARVDs) in the treatment of HIV/AIDS have been promising and effective especially amongst adults as it suppresses the viral load, thereby improving the life expectancy of HIV patients. However, the adoption of the treatment amongst children living with HIV have proved to be challenging. This is because of the poor drug adherence or non-compliance resulting from the lack of child-friendly formulations. The dosage forms are typically large tablets which have led to difficulty in swallowing or needs breaking of the tablets to obtain the correct dose and potentially some sort of dosage form manipulation by mixing it with milk or juice. The limited paediatric formulations that are available are mostly unpalatable, despite being formulated in a syrup or liquid, it still presents with a bitter taste. Therefore, all these factors combined have emphasized the need for child friendly dosage forms for children suffering from this debilitating disease.
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    The physicochemical characterisation, compatibility testing and solid-state form screening of terizidone - Pyridoxine combinations
    (University of Western Cape, 2021) Musafili, Ngabo Yves; Aucamp, Marique
    Terizidone (TZD) is considered an essential anti-tuberculosis drug and in South Africa it is prescribed as part of the multi-drug resistant tuberculosis (MDR-TB) treatment regimen. From a literature study it became apparent that very little is known in terms of the physicochemical characteristics of TZD and only one literature source mentions one polymorphic form of this drug. Furthermore, it exhibits neurotoxicity as an adverse effect, leading to the concomitant administration of pyridoxine (PDX) to counteract the TZD-induced side effects. MDR-TB patients experience major side effects from taking the drug for a long period (18 months) and it often results in resistance and poor adherence. This study therefore focused on the possibility to combine TZD and PDX either as co-crystals or as co-amorphous solid-state forms. In order to achieve this a complete physicochemical profile of TZD was determined, since very limited information could be found in literature.
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    Selected polyols as co-formers for pharmaceutical solid dispersions
    (Universty of the Western Cape, 2024) Poka, Madan Sai; Aucamp, Marique
    Poor aqueous solubility is a major concern for most new chemical entities (NCEs) developed for oral drug delivery as well as for almost 70% of registered and already marketed drugs. Solid-state alterations such as solid dispersions (SDs), co-amorphous and co-crystal systems have taken the lead over the past two decades, in an effort to address the challenge of poor drug solubility. One of the common factors amongst these techniques, that play a significant role in solubility enhancement, is the type of carrier or co-former used. Low molecular weight excipients such as amino acids, citric acid and a few sugars were studied as potential co-formers. However, the efforts made in identifying new low molecular weight excipients were modest. Given their low molecular weight, safety, hydrophilic nature and having high hydrogen bonding propensity makes polyols an interesting option to be explored as carriers.
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    The validation of a simple, robust, stability-indicating rp-hplc method for the simultaneous detection of lamivudine, tenofovir disoproxil fumarate, and dolutegravir sodium in bulk material and pharmaceutical formulations
    (Hindawi, 2022) Omoteso, Omobolanle Ayoyinka; Milne, Marnus; Aucamp, Marique
    An effective analytical method is requisite to ensure the accurate identification and quantification of drug(s), either in bulk material or in complex matrices, which form part of finished pharmaceutical products. For the purpose of a pharmaceutical formulation study, it became necessary to have a simple, yet robust and reproducible reversed-phase HPLC method for the simultaneous detection and quantification of lamivudine (3TC), tenofovir disoproxil fumarate (TDF), and dolutegravir sodium (DTG) in bulk form, complex polymeric matrices, and during drug release studies. A suitable method was developed using a Kinetex® C18, 250 × 4.6 mm column as stationary phase and a mobile phase consisting of 50 : 50 v/v methanol and water with 1 mL orthophosphoric acid, with a flow rate of 1.0 mL/min and column temperature maintained at 35°C. A detection wavelength of 260 nm and an injection volume of 10 μL were used. ,e method was validated according to the International Conference on Harmonization (ICH) guideline Q2 (R1), and the parameters of linearity and range, accuracy, precision, specificity, limit of detection (LOD), limit of quantification (LOQ), robustness, and stability were all determined. Acceptable correlation coefficients for linearity (R2) of >0.998 for each of the three drugs were obtained. ,e LOD was quantified to be 56.31 μg/mL, 40.27 μg/mL, and 7.00 μg/mL for 3TC, TDF, and DTG, respectively, and the LOQ was quantified as 187.69 μg/mL, 134.22 μg/mL, and 22.5 μg/mL for 3TC, TDF, and DTG, respectively. In relation to all the determined validation parameters, this method proves to be suitable for the accurate identification and quantification of the three ARVs, either alone or in combination, as well as when incorporated into polymeric matrices. Furthermore, the method proves to be suitable to detect degradation of the compounds.
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    Zebrafish behavioral response to ivermectin: Insights into potential neurological risk
    (Elsevier, 2022) Powrie, Yigael; Strydom, Morné; Aucamp, Marique
    Ivermectin is a well‐known and widely used anti‐parasitic drug. Recently, in vitro data suggest anti‐viral effi- cacy of the drug, albeit at much higher concentrations than currently approved. Despite warnings by several governing bodies, the (uncontrolled) human use of ivermectin has significantly increased during the COVID‐ 19 epidemic. This study thus aimed to elucidate potential neurological risk of particularly the veterinary for- mulation of ivermectin in comparison to pure ivermectin. Zebrafish eggs (1hpf) and larvae (4dpf) were exposed to a range of concentrations of either pure ivermectin (IVM) or a veterinary formulation (V‐IVM) for a period of 24 hours. Behavioral responses to both treatments were assessed at various timepoints using the pentylenete- trazol assay, the light–dark assay and a 5‐day teratogenesis protocol. In addition, dissolution rates were calcu- lated for both treatments.