Browsing by Author "10096078 - Steenekamp, Jan Harm"
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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 ... -
Combination therapy of western drugs and herbal medicines: recent advances in understanding interactions involving metabolism and efflux
Gouws, Chrisna; Steyn, Dewald; Du Plessis, Lissinda; Steenekamp, Jan; Hamman, Josias H. (Taylor & Francis, 2012)Introduction: While complementary and alternative medicine markets prosper with an increasing number of consumers of herbal medicines, there is an associated likelihood for herb–drug interactions to occur. Modulation of ... -
Development and evaluation of a double-phase multiple-unit dosage form for enhanced insulin intestinal delivery
De Bruyn, Suzette; Willers, Clarissa; Steyn, Dewald; Steenekamp, Jan; Hamman, Josias (Bentham Science, 2018)Background: The oral route is the most preferred route of administration for selfmedication, but poor membrane permeability and pre-systemic degradation are key challenges that need to be addressed. Objective: The purpose ... -
Development of a bead-in-matrix delivery system for insulin
Strydom, C. (North-West University, 2018)The oral route remains the most convenient and popular route for drug administration. However, for therapeutic peptide drugs, parenteral administration remains the most used route of administration as the use of the oral ... -
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 ... -
Drug bioavailability enhancing agents of natural origin (bioenhancers) that modulate drug membrane permeation and pre-systemic metabolism
Peterson, Bianca; Weyers, Morné; Steenekamp, Jan H.; Steyn, Johan D.; Gouws, Chrisna; Hamman, Josias H. (MDPI, 2019)Many new chemical entities are discovered with high therapeutic potential, however, many of these compounds exhibit unfavorable pharmacokinetic properties due to poor solubility and/or poor membrane permeation characteristics. ... -
Effect of moisture content, temperature and exposure time on the physical stability of chitosan powder and tablets
Viljoen, Joe M.; Steenekamp, Jan H.; Marais, Andries F.; Kotzé, Awie F. (Taylor & Francis, 2014)Context: Chitosan does not rank highly regarding its employment as tablet filler due to certain limitations. Undesirable properties that limit its utilization as excipient in solid dosage forms include its hydration ... -
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 ... -
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 ... -
Formulation and evaluation of selected transmucosal dosage forms containing a double fixed-dose of acyclovir and ketoconazole
Viljoen, Joe M.; Botes, Danélia; Steenekamp, Jan H. (Elsevier, 2018)Viral and fungal dermatological manifestations are often the first and only sign of HIV/AIDS. They are cosmetically disfiguring and threaten the quality of life, but can be treated by acyclovir and ketoconazole, correspondingly. ... -
Formulation of a multiple-unit pellet solid oral delivery system for metformin and gliclazide
Ngoy, K.C. (North-West University, 2018)Non-compliance is one of the contributing factors leading to poor treatment response in patients with chronic conditions such as diabetes mellitus (DM), due to the complex regimens often used in the management of these ... -
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 ... -
Herbal hepatotoxicity: current status, examples, and challenges
Calitz, Carlemi; Du Plessis, Lissinda; Gouws, Chrisna; Steyn, Dewald; Steenekamp, Jan; Muller, Christo; Hamman, Sias (Taylor & Francis, 2015)Introduction: Herbal medicines have commonly been considered safe by the general public due to their natural origin and long history of traditional uses. In contrast to this belief, many plants produce toxic substances as ... -
Impact of traditional African medicine on drug metabolism and transport
Calitz, Carlemi; Steenekamp, Jan H.; Steyn, Johan D.; Gouws, Chrisna; Viljoen, Joe M.; Hamman, Josias H. (Taylor & Francis, 2014)Introduction: Africa is a continent of rich plant biodiversity with many indigenous plants having a long history of being used for medicinal purposes. A considerable number of patients consult traditional healers in ... -
In vitro oral drug permeation models: the importance of taking physiological and physico-chemical factors into consideration
Joubert, Ruan; Steyn, Johan Dewald; Steenekamp, Jan Harm; Du Preez, Jan Lourens; Hamman, Josias Hendrik; Heystek, Hendrik Jacobus (Taylor & Francis, 2016)Introduction: The assessment of intestinal membrane permeability properties of new chemical entities is a crucial step in the drug discovery and development process and a variety of in vitro models, methods and techniques ... -
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 ... -
Moulded cross-linked chitosan matrix systems for controlled drug release
Tarirai, Clemence; Steenekamp, Jan H.; Hamman, Josias H.; Enslin, Gill M. (Taylor & Francis, 2011)Matrix-type drug delivery systems were prepared by moulding and drying cross-linked chitosan gels in 24-well plates and they were evaluated in terms of their physical properties, drug content, surface morphology and swelling. ... -
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 ... -
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 ...