For a drug to have a therapeutic effect, it has to reach its site of action in sufficient quantities. The Pheroid drug delivery system enhances the absorption of drugs in various pharmacological categories and is the focus of this study. A number of patents are registered in various countries to protect its application. Pheroid technology is trademarked, but may for ease of reading, be called Pheroid(s) only. The Pheroid itself is composed of an organic carbon backbone composed of unsaturated fatty acids with some side-chain interactions that result in self-emulsifying characteristics. The resulting vesicles and nano-sponges can entrap hydrophilic, hydrophobic or amphiphilic compounds for biomedical and agricultural application and can be manipulated as to loading ability, mechanical resistance, permeability, size and solubility. Pheroid was investigated for its potential use in the areas of vaccines, peptide drugs, topical products and cosmeceuticals, antimicrobial treatments and agriculture. In all of these areas, the Pheroid has indeed shown applicability: the results showed improved uptake and/or efficacy of the entrapped chemical or biological compounds after administration by a number of administration routes. For oral administration, a precursor format, the pro-Pheroid, was used, wherein the vesicles and/or sponges are formed post-administration. Proof of concept studies on the in vivo absorption and bioavailability, as well as studies on in vitro efficacy of Pheroid-based formulations were carried out for antimicrobials, such as tuberculosis drugs, antimalarials and antiretrovirals. In all cases, the in vitro efficacy of the active compounds was increased, compared to well-known standard drug treatments. In a phase I bio-equivalence study, a Pheroid-containing combination formulation was compared against the comparative market leader. The results demonstrated that the bioavailability of the active compounds in the Pheroid was at least as good but mostly significantly better than that of the comparative medication. In addition, the incidence of side-effects was decreased in the case of the Pheroid formulations. Furthermore, in vitro results indicate that drug resistance can at least partially be negated. Pheroid technology may also be capable of protecting labile drugs such as peptides against degradation and increasing efficacy so that lower dosages can be administered less frequently and with fewer side effects. Based on in vitro and in vivo results, a number of products are currently in development. The application of Pheroid technology is potentially limitless and includes such areas as TB, malaria, cancer, AIDS, gene delivery, vaccines, patented medicines and generics and agriculture. / Thesis (Ph.D. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.

For a drug to have a therapeutic effect, it has to reach its site of action in sufficient quantities. The Pheroid drug delivery system enhances the absorption of drugs in various pharmacological categories and is the focus of this study. A number of patents are registered in various countries to protect its application. Pheroid technology is trademarked, but may for ease of reading, be called Pheroid(s) only. The Pheroid itself is composed of an organic carbon backbone composed of unsaturated fatty acids with some side-chain interactions that result in self-emulsifying characteristics. The resulting vesicles and nano-sponges can entrap hydrophilic, hydrophobic or amphiphilic compounds for biomedical and agricultural application and can be manipulated as to loading ability, mechanical resistance, permeability, size and solubility. Pheroid was investigated for its potential use in the areas of vaccines, peptide drugs, topical products and cosmeceuticals, antimicrobial treatments and agriculture. In all of these areas, the Pheroid has indeed shown applicability: the results showed improved uptake and/or efficacy of the entrapped chemical or biological compounds after administration by a number of administration routes. For oral administration, a precursor format, the pro-Pheroid, was used, wherein the vesicles and/or sponges are formed post-administration. Proof of concept studies on the in vivo absorption and bioavailability, as well as studies on in vitro efficacy of Pheroid-based formulations were carried out for antimicrobials, such as tuberculosis drugs, antimalarials and antiretrovirals. In all cases, the in vitro efficacy of the active compounds was increased, compared to well-known standard drug treatments. In a phase I bio-equivalence study, a Pheroid-containing combination formulation was compared against the comparative market leader. The results demonstrated that the bioavailability of the active compounds in the Pheroid was at least as good but mostly significantly better than that of the comparative medication. In addition, the incidence of side-effects was decreased in the case of the Pheroid formulations. Furthermore, in vitro results indicate that drug resistance can at least partially be negated. Pheroid technology may also be capable of protecting labile drugs such as peptides against degradation and increasing efficacy so that lower dosages can be administered less frequently and with fewer side effects. Based on in vitro and in vivo results, a number of products are currently in development. The application of Pheroid technology is potentially limitless and includes such areas as TB, malaria, cancer, AIDS, gene delivery, vaccines, patented medicines and generics and agriculture. / Thesis (Ph.D. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.

Rotavirus infection causes severe gastroenteritis, affecting all children under the age of five regardless of hygiene or water quality. The currently licensed vaccines succeeded in reducing diarrhoea worldwide, but they still have shortcomings, especially the efficacy of the vaccines in developing countries. One of the main reasons for this can be due to the difference in strains, since the strains used to develop the currently licensed vaccines (RotaTeq and Rotarix) were selected from strains circulating in the developed world (G1, G2, G3 and G4), while the main strains present in Africa (G8, G9 and G12) were not included. A second shortcoming of the currently licensed vaccines is the cost of these vaccines. The vaccines are very expensive and most developing countries cannot afford the vaccines as well as the fact that the manufacturing companies cannot produce enough vaccines for all the countries. An attractive alternative to the currently licensed rotavirus vaccines is the non-live vaccine candidate, virus-like particles, which can provide a possible cheaper, safer and efficacious alternative or complement the currently licensed vaccines. Therefore, in this study a South African G9P[6] rotavirus strain, RVA/Humanwt/ ZAF/GR10924/1999/G9P[6], was used to determine whether or not co-expression of the structural proteins VP2 (genome segment 2) and VP6 (genome segment 6) was possible in bacteria and yeast. The South African GR10924 G9P[6] neonatal strain was previously obtained from a stool sample and the nucleotide consensus sequence was determined for both genome segment 2 (VP2) and genome segment 6 (VP6). Bacterial codon optimised coding regions or open reading frames were used in this study. The open reading frames (ORFs) of the genome segments encoding, VP2 and VP6, were cloned into the expression vector pETDuet-1, which allows for the simultaneous expression of two genes in bacteria. The ORF of genome segment 6 was purchased from GeneScript and the ORF of genome segment 2 was obtained from Dr AC Potgieter (Deltamune (Pty) Ltd R&D, South Africa). Compatible restriction enzyme sites were used to sub-clone the ORF of the bacterial codon optimised genome segments into the expression vector. Only the expression of the VP6 protein in bacteria was observed with Coomassie stained SDS-PAGE. The ORFs encoding VP2 (genome segment 2) and VP6 (genome segment 6) of the wild type GR10924 G9P[6] strain were cloned into the wide range yeast expression system vector, pKM173, which allows for the simultaneous expression of more than one gene. Several yeast strains were used in this study namely Kluyveromyces marxianus, Kluyveromyces lactis, Candida deformans, Saccharomyces cerevisiae, Yarrowia lipolytica, Arxula adeninivorans, Hansenula polymorpha and Debaryomyces hansenii. Expression of both proteins was not detected in the several yeast strains, as seen with western blot analysis. DNA extractions were done on two colonies of each yeast strain that were used for western blot analysis to evaluate successful integration into the yeast genomes. Only a few of the colonies contained either both of the genome segments or only one of the two genome segments of interest. To summarise, the simultaneous expression of VP2 and VP6 from rotavirus GR10924 G9P[6] was not successful in bacteria or yeast, but it was possible to soluble express the bacterial codon optimised GR10924 G9P[6] VP6 in bacteria using the pETDuet-1 as expression vector. / MSc (Biochemistry), North-West University, Potchefstroom Campus, 2015

Rotavirus infection causes severe gastroenteritis, affecting all children under the age of five regardless of hygiene or water quality. The currently licensed vaccines succeeded in reducing diarrhoea worldwide, but they still have shortcomings, especially the efficacy of the vaccines in developing countries. One of the main reasons for this can be due to the difference in strains, since the strains used to develop the currently licensed vaccines (RotaTeq and Rotarix) were selected from strains circulating in the developed world (G1, G2, G3 and G4), while the main strains present in Africa (G8, G9 and G12) were not included. A second shortcoming of the currently licensed vaccines is the cost of these vaccines. The vaccines are very expensive and most developing countries cannot afford the vaccines as well as the fact that the manufacturing companies cannot produce enough vaccines for all the countries. An attractive alternative to the currently licensed rotavirus vaccines is the non-live vaccine candidate, virus-like particles, which can provide a possible cheaper, safer and efficacious alternative or complement the currently licensed vaccines. Therefore, in this study a South African G9P[6] rotavirus strain, RVA/Humanwt/ ZAF/GR10924/1999/G9P[6], was used to determine whether or not co-expression of the structural proteins VP2 (genome segment 2) and VP6 (genome segment 6) was possible in bacteria and yeast. The South African GR10924 G9P[6] neonatal strain was previously obtained from a stool sample and the nucleotide consensus sequence was determined for both genome segment 2 (VP2) and genome segment 6 (VP6). Bacterial codon optimised coding regions or open reading frames were used in this study. The open reading frames (ORFs) of the genome segments encoding, VP2 and VP6, were cloned into the expression vector pETDuet-1, which allows for the simultaneous expression of two genes in bacteria. The ORF of genome segment 6 was purchased from GeneScript and the ORF of genome segment 2 was obtained from Dr AC Potgieter (Deltamune (Pty) Ltd R&D, South Africa). Compatible restriction enzyme sites were used to sub-clone the ORF of the bacterial codon optimised genome segments into the expression vector. Only the expression of the VP6 protein in bacteria was observed with Coomassie stained SDS-PAGE. The ORFs encoding VP2 (genome segment 2) and VP6 (genome segment 6) of the wild type GR10924 G9P[6] strain were cloned into the wide range yeast expression system vector, pKM173, which allows for the simultaneous expression of more than one gene. Several yeast strains were used in this study namely Kluyveromyces marxianus, Kluyveromyces lactis, Candida deformans, Saccharomyces cerevisiae, Yarrowia lipolytica, Arxula adeninivorans, Hansenula polymorpha and Debaryomyces hansenii. Expression of both proteins was not detected in the several yeast strains, as seen with western blot analysis. DNA extractions were done on two colonies of each yeast strain that were used for western blot analysis to evaluate successful integration into the yeast genomes. Only a few of the colonies contained either both of the genome segments or only one of the two genome segments of interest. To summarise, the simultaneous expression of VP2 and VP6 from rotavirus GR10924 G9P[6] was not successful in bacteria or yeast, but it was possible to soluble express the bacterial codon optimised GR10924 G9P[6] VP6 in bacteria using the pETDuet-1 as expression vector. / MSc (Biochemistry), North-West University, Potchefstroom Campus, 2015