Development of a nystatin-loaded micellar system for oral mucoadhesion
- Authors: Sarpong, Nancy Owusu Akyere
- Date: 2019
- Subjects: Medical microbiology , HIV infections -- Treatment Clinical pharmacology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/43556 , vital:36918
- Description: Oropharyngeal Candidiasis (OPC) is an opportunistic fungal infection that affects mostly infants and immunocompromised patients. In recent years, the disease has been on the rise due to an increased life span, the HIV pandemic and the increased use of broad spectrum antibiotics. OPC may be treated using a nystatin suspension, which is not as effective as it could be due to the mechanism by which the suspension is applied to the affected tissue. This research aims to improve the effectiveness of nystatin, for the treatment of OPC, by proposing a nystatin loaded micellar system incorporated into a mucoadhesive system for drug delivery. This will ensure that nystatin is gradually released from the film, thus increasing retention time of nystatin at the affected area. In this study, a mixture design was developed, which was used to determine the most appropriate solvent system for nystatin solubilization. Optimisation of the micelle formulation was achieved by using the central composite rational design (CCRD). The two factors that were taken into consideration were the temperature of the hydration medium (water) and the length of time the micellar solution was exposed to the temperature environment of the rotary evaporator. The responses that were investigated were the mean particle size, mean polydispersity index (PDI), mean zeta potential, change in mean particle size and change in mean PDI. The optimal micelle formulation was characterised for size, stability, morphology and drug encapsulation efficiency. The micelles were found to be spherical and stable with an acceptable size range. However, their drug encapsulation efficiency was low. The mucoadhesive film was formulated and characterised for physical characteristics, pliability, percentage swelling index and drug release profile. The film was found to be highly pliable and evenly distributed with a smooth surface; no bumps or bubbles were visible. The film was able to swell to up to 550 %. In vitro studies showed that nystatin was gradually released from the film.
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- Date Issued: 2019
The coordination and extractive chemistry of the later 3d transition metal ions with N, N'-donor imidazole-based ligands
- Authors: Moleko, Pulleng
- Date: 2014
- Subjects: Solvent extraction , Coordination compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/8382 , vital:26352
- Description: The application of bidentate N,N'-donor ligands, such as 2,2'-biimidazole (BIIMH2) and 2,2'-pyridylimidazole (PIMH) and (1H-benzimidazol-2yl)-N-methylmethanamine (BIMAH), in the solvent extraction of base metal ions from an acidic sulfate/sulfonate medium was investigated. PIMH and BIMAH showed selectivity for Ni(II) with the only interfering ion being Cu(II) in the pH range 1.2-1.8 but BIIMH2 lacked selectivity. The extraction patterns observed were influenced by stereochemical aspects, and this agreed well with the envisaged design of nickel(II)-specific extractants through stereochemical “tailor-making” which is proposed in this study. The extraction patterns were explained from a coordination chemistry point of view using spectroscopic analysis and single crystal X-ray analysis to diagnose the geometry of the complexes formed from the interaction of the base metal ions with the ligands. The formation of the trigonal bipyrimidal [Cu(PIM)2(H2O)](SO4) complex, with a water molecule coordinated, while nickel(II) forms a square planar bisPIMH was put forward as the reason for extraction pattern observed with this ligand. Cobalt(II) also forms a bisPIMH complex but has two water molecules coordinated in the formation of a distorted octahedral complex, and this results in less extractable species. A similar observation as for PIMH was noticed in BIMAH complexation reactions. The BIIMH2 complexes were found to be distorted octahedral, through the bis-coordination of BIIMH2 and two sulfonate ions, resulting in lack of pH-metric separation of the later 3d metal ions. The stability constants data was in agreement with what was observed in the solvent extraction and coordination chemistry studies for the three ligand systems.
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- Date Issued: 2014
Enhancing the organisational culture at Spar Eastern Cape: a case study
- Authors: Dick, Siyolo
- Date: 2013
- Subjects: Corporate culture -- South Africa -- Eastern Cape , Teams in the workplace -- South Africa -- Eastern Cape , Chain stores -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8885 , http://hdl.handle.net/10948/d1020804
- Description: SPAR Eastern Cape is a special organisation. It is an extraordinary place to work and have fun at. The organisation celebrated its twentieth “birthday” in 2013. Operating in a very difficult sector, this business has done extremely well in establishing itself as one of the leading businesses in the Eastern Cape. The success of this incredible business is driven by employees from all levels. With an extreme conviction in the apothegm that “none of us is as smart as all of us”, the organisation is built around high performance teams through a unique culture called: Amafela Ndawonye (referred to as Amafela hereafter). “Amafela” has been in operation at SPAR Eastern Cape since the organisation’s inauguration in 1993. Organisational cultures are dynamic. Organisational cultures shift, incrementally and constantly, in response to external and internal changes. Trying to assess an organisational culture is therefore complicated by the reality that one is trying to hit a moving target. However, a possibility exists that culture enhancement can be managed as a continuous process rather than big shifts (often in response to a crisis). A stable destination with regards to organisational culture should never be reached. The culture of an organisation should always be learning and developing. This prompted the researcher to ask the question, as an organisation responds to internal and external changes; can it lose its relevancy in the process? The primary objective of this research is to determine whether the commitment to the culture of “Amafela” and relevancy thereof at SPAR Eastern Cape is declining. The first step in achieving this objective was an in-depth theoretical study. The second step, and in order to achieve this objective, was an empirical survey conducted to canvas the opinions of (N= 149) respondents at SPAR Eastern Cape. The main findings of this research conducted at SPAR Eastern Cape can be summarised as follows: The organisational culture was assessed according to how respondents interpret the organisation’s existing organisational culture, and thus underlining areas in need of enhancement. In general the outcome of the survey exhibited that a large number of employees at SPAR Eastern Cape denoted that the culture of “Amafela” is still strong and is still relevant in the organisation. In this research, good to excellent levels of consistency for all eleven factors of “Amafela” were achieved. The items are therefore parallel in the test. Organisational leaders will influence the function of the people within the organisation. Moreover, leadership will set the present and future course of the company. This research articulates a correlation between leadership and “Amafela” factors. The eleven dimensions of the “Amafela” factors ranked according from favourable to less favourable. Customer focus emerged as the factor which most respondents agreed and strongly agreed with. It can be concluded then, that the culture of “Amafela Ndawonye” at SPAR Eastern Cape has the full support of the employees and is still relevant in the organization.
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- Date Issued: 2013
The impact of the absence of a total productive maintenance (TPM) program at a plastic painting plant
- Authors: Hempel, Calvern Anthony
- Date: 2007
- Subjects: Plant maintenance -- Management , Total productive maintenance -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8590 , http://hdl.handle.net/10948/524 , Plant maintenance -- Management , Total productive maintenance -- South Africa
- Description: This research was concerned with investigating “the absence of Total Productive Maintenance (TPM)” at a plastic painting plant. TPM is a combination of operations and maintenance activities and is performed by operators under their own authority and is called “autonomous maintenances”. The author has tested the degree of implementation of TPM by using a sevenstep TPM implementation model this highlighted an absence of TPM in the organisation investigated. TPM is a relatively new concept in the South African automotive industry and has not been fully accepted by management as a solution to the maintenance problems in the organisation. Due to a long implementation period and the difficulty in measuring the benefits of the TPM program for the organisation TPM tends not to be implemented by companies. The research studies several maintenance philosophies each with its own advantages and disadvantages. The benefits that arise from the implementation of an effective TPM philosophy were explored. The development of an effective improved model for the implementation of TPM was investigated. Maintenance engineers and managers in any organisation can use this model to implement an effective TPM program. The seven-step TPM implementation model formed the basis for the compilation of a questionnaire. A survey was conducted to determine if an absence of TPM existed in a plastic painting plant. The results from the survey were drawn up and recommendations to further develop a model for the implementation of TPM was put forward.
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- Date Issued: 2007