Browsing by Author "Hamman, Josias"
Now showing items 1-20 of 22
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Absorptive and secretory transport of selected artemisinin derivatives across Caco-2 cell monolayers
Heyns, Jaco; Willers, Clarissa; Haynes, Richard K.; Wong, Ho N.; Hamman, Josias; Gouws, Chrisna (Bentham Science, 2018)Background: Malaria continues to be a major health concern and affects more than 200 million people a year. Drugs currently used for treatment of malaria are increasingly rendered ineffectual by the ongoing emergence of ... -
Amorphous azithromycin with improved aqueous solubility and intestinal membrane permeability
Aucamp, Marique; Odendaal, Roelf; Liebenberg, Wilna; Hamman, Josias (Taylor & Francis, 2015)Azithromycin (AZM) is a poorly soluble macrolide antibacterial agent. Its low solubility is considered as the major contributing factor to its relatively low oral bioavailability. The aim of this study was to improve the ... -
Artificial membranes in combination with selected natural oils for in vitro drug passive diffusion screening in Ussing type chamber apparatus applied to gastro-retentive systems
Fensham, Mark; Steenekamp, Jan; Jacobs, Adriaan; Hamman, Josias (Taylor & Francis, 2020)This study aimed at developing an effective in vitro technique for the screening of drug passive diffusion utilising artificial membranes in combination with three selected oils (i.e. cognac, emu, and olive oil). Artificial ... -
Characterization of an alginate encapsulated LS180 spheroid model for anti-colorectal cancer compound screening
Smit, Tanya; Calitz, Carlemi; Willers, Clarissa; Svitina, Hanna; Hamman, Josias; Gouws, Chrisna; Wrzesinski, Krzysztof (ACS, 2020)Colorectal cancer is one of the leading causes of cancer-related deaths. A main problem for its treatment is resistance to chemotherapy, requiring the development of new drugs. The success rate of new candidate cancer drugs ... -
Development of multiple-unit pellet system tablets by employing the SeDeM expert diagram system. I. Pellets with different sizes
Hamman, Hannlie; Hamman, Josias; Wessels, Anita; Scholtz, Jacques; Steenekamp, Jan Harm (Taylor & Francis, 2017)Multiple-unit pellet systems (MUPS) provide several pharmacokinetic and pharmacodynamic advantages over single-unit dosage forms, however, compression of pellets into MUPS tablets present certain challenges. Although the ... -
Development of multiple-unit pellet system tablets by employing the SeDeM expert diagram system. II. Pellets containing different active pharmaceutical ingredients
Hamman, Hannlie; Hamman, Josias; Wessels, Anita; Scholtz, Jacques; Steenekamp, Jan (Taylor & Francis, 2019)The SeDeM Expert Diagram System (SeDeM EDS) was originally developed to provide information about the suitability of powders to produce direct compressible tablets. Multiple-unit pellet systems (MUPS) are dosage forms ... -
Eudragit® L100/N-trimethylchitosan chloride microspheres for oral insulin delivery
Marais, Etienne; Hamman, Josias; Du Plessis, Lissinda; Lemmer, Righard; Steenekamp, Jan (MDPI, 2013)Effective oral delivery of protein and peptide drugs remains an active topic in scientific research. In this study, matrix type microspheres were prepared with Eudragit® L100 containing N-trimethylchitosan chloride to ... -
Evaluation of isolated fractions of aloe vera gel materials on indinavir pharmacokinetics: in vitro and in vivo studies
Wallis, Lonette; Malan, Maides; Gouws, Chrisna; Steyn, Dewald; Ellis, Suria; Hamman, Josias; Otto, Daniel P. (Bentham Science, 2016)Aloe vera is a plant with a long history of traditional medicinal use and is consumed in different products, sometimes in conjunction with prescribed medicines. A. vera gel has shown the ability to modulate drug absorption ... -
Excipients with specialized functions for effective drug delivery
Hamman, Josias; Steenekamp, Jan (Taylor & Francis, 2012)Introduction: There is a growing need for the development of pharmaceutical excipients that could improve product performance and overcome the shortcomings of new drug moieties, such as their poor solubility and membrane ... -
Herb-drug pharmacokinetic interactions: transport and metabolism of indinavir in the presence of selected herbal products
Calitz, Carlemi; Gouws, Chrisna; Viljoen, Joe; Steenekamp, Jan; Hamman, Josias (MDPI, 2015)Patients receiving anti-retroviral drug treatment are sometimes simultaneously taking herbal remedies, which may result in pharmacokinetic herb-drug interactions. This study aimed to determine if pharmacokinetic interactions ... -
In vitro and ex vivo experimental models for evaluation of intranasal systemic drug delivery as well as direct nose‐to‐brain drug delivery
Haasbroek‐Pheiffer, Anja; Van Niekerk, Suzanne; Van der Kooy, Frank; Cloete, Theunis; Steenekamp, Jan; Hamman, Josias (Wiley, 2023)The intranasal route of administration provides a noninvasive method to deliver drugs into the systemic circulation and/or directly into the brain. Direct nose‐to‐ brain drug delivery offers the possibility to treat ... -
The in vitro and in vivo effects of hypoxis hemerocallidea on indinavir pharmacokinetics: modulation of efflux
Havenga, Kaylee; Steyn, Dewald; Hamman, Josias; Abay, Efrem; Wiesner, Lubbe; Viljoen, Alvaro (Thieme, 2018)(African potato) is a popular medicinal plant that has been used traditionally for the treatment of various disorders. Some HIV/AIDS patients use this traditional medicine together with their antiretroviral therapy. This ... -
In vitro drug absorption enhancement effects of Aloe vera and Aloe ferox
Beneke, Catharina; Hamman, Josias; Viljoen, Alvaro (Österreichische Apotheker-Verlagsgesellschaft, 2012)The effect of whole leaf and gel materials from two aloe species (Aloe vera and A. ferox) was compared with that of the precipitated polysaccharides from these aloe materials on the transepithelial electrical resistance ... -
In vitro drug permeation enhancement potential of aloe gel materials
Lebitsa, Tebogo; Hamman, Josias; Lu, Zhilei; Viljoen, Alvaro (Bentham Science, 2012)Aloe vera gel previously showed the ability to increase the bioavailability of vitamins and to enhance the in vitro transport of a macromolecular drug across intestinal epithelial cell monolayers. The purpose of this study ... -
Modulation of drug efflux by aloe materials: an in vitro investigation across rat intestinal tissue
Beneke, Carien; Hamman, Josias; Viljoen, Alvaro (Medknow, 2013)Background: Clinically, significant herb-drug interactions have been previously documented and can be pharmacodynamic and/or pharmacokinetic in nature. Pharmacokinetic interactions have been attributed to induction or ... -
More good news about polymeric plant- and algae-derived biomaterials in drug delivery systems
Scholtz, Jacques; Van der Colff, Jaco; Steenekamp, Jan; Stieger, Nicole; Hamman, Josias (Bentham Science, 2014)Natural polymers are continuously investigated for use in pharmaceutical and tissue engineering applications due to the renewability of their supply. Besides the conventional use of natural materials in dosage form design ... -
Novel non-invasive protein and peptide drug delivery approaches
Wallis, Lonette; Kleynhans, Elmarie; Du Toit, Trizel; Gouws, Chrisna; Steyn, Dewald; Steenekamp, Jan; Viljoen, Joe; Hamman, Josias (Bentham Science, 2014)Protein and peptide based therapeutics are typically administered by injection due to their poor uptake when administered via enteral routes of drug administration. Unfortunately, chronic administration of these drugs ... -
Permeation enhancement effects of leaf materials from different aloe species on in vitro and ex vivo nasal epithelial models
Gerber, Werner; Steyn, Dewald; Kotzé, Awie; Svitina, Hanna; Weldon, Ché; Hamman, Josias (2020)Introduction: The nasal route of drug administration offers an alternative way for oral drug delivery and has the benefit of avoiding first-pass metabolism through drug delivery directly into the systemic circulation. The ... -
Potential herb-drug pharmacokinetic interactions between African Wild Olive leaf extract and selected antihypertensive drugs
Mmopele, Katlego; Hamman, Josias; Willers, Clarissa; Combrinck, Sandra; Chen, Weiyang (Thieme, 2018)The African wild olive (Olea europaea subsp. africana) is traditionally used as a hypotensive agent. Herb-drug interactions may result from the concurrent use of herbal medicines and conventional prescription drugs. This ... -
The role of functional excipients in solid oral dosage forms to overcome poor drug dissolution and bioavailability
Van der Merwe, Jannes; Steenekamp, Jan; Dewald, Steyn; Hamman, Josias (MDPI, 2020)Many active pharmaceutical ingredients (APIs) exhibit poor solubility and low dissolution rates in aqueous environments such as the luminal fluids of the gastrointestinal tract. The oral bioavailability of these compounds ...