https://commons.ru.ac.za/vital/access/manager/Index en-us 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:27797 Wed 31 May 2023 14:45:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41962 Wed 26 Oct 2022 16:01:49 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:38989 Wed 21 Jul 2021 13:20:55 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27823 Wed 21 Jul 2021 12:10:53 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42922 Wed 19 May 2021 10:55:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28394 Wed 17 May 2023 16:02:37 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28146 Wed 17 May 2023 08:48:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28235 Wed 15 Sep 2021 14:30:53 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28200 Wed 15 Sep 2021 12:17:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:38577 Wed 12 Oct 2022 12:44:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30568 Wed 12 Oct 2022 12:01:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:36591 Wed 12 Oct 2022 11:52:01 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28152 Wed 12 Oct 2022 11:48:48 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41444 Wed 12 Oct 2022 11:47:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42939 Wed 12 Jul 2023 08:28:50 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:35822 Wed 04 Aug 2021 14:30:34 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28139 Wed 03 May 2023 14:17:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28508 Wed 03 May 2023 13:07:18 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:31446 Tue 28 Feb 2023 08:54:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27760 Tue 27 Jul 2021 12:39:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42790 Tue 25 May 2021 09:30:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42791 Tue 25 May 2021 08:48:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42769 Tue 23 May 2023 11:45:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42798 Tue 18 May 2021 15:55:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42938 Tue 16 Nov 2021 09:37:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30600 Tue 15 Aug 2023 15:50:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42201 Tue 15 Aug 2023 11:29:30 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28061 Tue 15 Aug 2023 11:05:18 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42891 Tue 14 Feb 2023 07:55:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27768 Tue 12 Oct 2021 15:53:29 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29124 Tue 11 Jul 2023 16:25:27 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28482 Tue 09 May 2023 15:34:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28370 Tue 06 Jun 2023 12:39:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30597 100 km) behaviour, respectively. Further behavioural diversity was observed with ‘resident’, ‘roaming’ and ‘embayment’ contingents identified based on varying levels of affinity to certain habitats. The presence of both resident and migratory individuals within the northernmost study during June and July, combined with available biological information, suggested that area-specific spawning may take place. While PAT, CPUE and CT largely aligned in determining area specific high-area use, results from network analyses and mixed effects models conducted on the PAT data supported the spawning hypothesis, with anomalous behaviour around specific receivers during the spawning season. All fish, regardless of behavioural contingent, displayed similar movement behaviour during the spawning season and this was driven by factors generally associated with reproduction, such as lunar illumination. Interestingly, these drivers were different from those that determined the area specific use of individuals outside of the spawning season. The environmental drivers of longshore migration into the northern study site were identified as a decline in water temperature and shorter day lengths. The results of this study highlight the importance of using a multi-method approach in determining migratory movement behaviour, area specific area use, and stock structure of key fisheries species. The identification of different behavioural contingents highlights the importance of acknowledging individual variation in movement and habitat-use patterns. This is particularly relevant as future climate change and spatiotemporal variation in fishing effort may artificially skew natural selection processes to favour certain behavioural groups. This study also highlighted the importance of scientists forming relationships with resource-users, such as recreational angling lodges in areas where limited research has been conducted. This is particularly relevant within the West African context where little is known about many of the fish species that are being increasingly targeted by tourism angling ventures.]]> Thu 29 Sep 2022 14:25:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:31213 Thu 29 Sep 2022 14:24:30 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30599 Thu 29 Sep 2022 14:23:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42759 10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.]]> Thu 29 Sep 2022 12:42:34 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28410 Thu 25 May 2023 15:03:12 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27004 Thu 22 Jul 2021 15:41:22 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27230 Thu 22 Jul 2021 14:38:29 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28208 Thu 18 May 2023 15:27:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28212 Thu 18 May 2023 13:14:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28707 Thu 13 May 2021 16:40:45 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:38509 Thu 13 May 2021 15:55:13 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28357 Thu 13 May 2021 15:31:22 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30711 Thu 13 May 2021 15:04:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30709 150% intensity) were old gravity schemes. Farmers on approximately 75% of Limpopo smallholder schemes are currently engaging in land exchange transactions in a highly insecure and un-formalised institutional setup. Land exchange prevalence longer than two years was moderately associated with cropping intensity and strongly associated with commercialisation. This result has three important implications. First, it suggests that more land is utilised on the schemes when there is vibrant land-leasing activity. Secondly, schemes with a higher prevalence of long-term leasing seem to have a strong tendency to be more commercialised. Thirdly, the duration of the lease is significant, as neither single-season, nor annual leases yielded any positive associations, while those exchanges that were two years or longer, were associated with increased performance. These findings highlight the potential for longer-term land-exchange interventions to address the widespread low land utilisation on smallholder schemes, and to catalyse more commercially-oriented farming. An irrigation scheme typology was derived from the cluster analysis and was aligned to a contemporary irrigation farming typology. The key descriptors included technology type, purpose of farming and scheme management type. By matching scheme type to the farmer typology (or typologies), strategic decisions regarding technology choices for infrastructure, land, and water institutional interventions can be better informed. All schemes demand attention to the multiple factors required to achieve performance, not least water-tenure security, irrigation management organisational development, and infrastructure modernisation. Complexity was demonstrated by the finding that multiple factors contribute to success, and that there are many dimensions that change independently and have a cascading effect through the system in ways that are difficult to predict. Agricultural systems support to achieve productivity and profitability are essential for success. The research findings lead to the recommendation that, in addition, strategic planners must also consider the implications of the dominant factors of water-technology choices so that these are manageable, and the dynamics of farm-size change based on land exchange processes, in order to harness new opportunities to maximise irrigation scheme performance in future.]]> Thu 13 May 2021 11:26:49 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:34076 Thu 13 May 2021 11:24:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:37667 Thu 13 May 2021 10:59:19 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:26580 99 % in selectively extracting the metalloporphyrins. The impact of the template on the affinity of recognition for NTPP was evaluated. The results showed that the NTPP adsorption capacity increased as the molar ratio of NTPP to styrene was increased from 1:1 to 3:1. The optimal ratio of template to functional monomer which yielded the best specific affinity and highest recovery (99.9 %) was 3:1. The effects of trifluoroacetic acid (TFA), dichloromethane (DCM), dimethyl sulphoxide (DMSO), pentane (PEN) on electro-spinnability of the polymer solutions and the morphological appearance of the nanofibers were investigated. The imprinted nanofibers exhibited the same selectivity specialism for both NTPP and VTPP. A remarkable stability in relation to reusability was observed when imprinted nanofibers were used, as they could be reused nine times without incurring any significant loss in removal efficiency. The results were validated by analysing a certified reference material. The imprinted sorbents were therefore found to be selective sorbents that are well suited for handling trace metals in organic media.]]> Thu 13 May 2021 09:54:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30589 50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.]]> Thu 13 May 2021 08:10:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:33249 Thu 13 May 2021 07:39:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28478 Thu 13 May 2021 07:35:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28540 Thu 13 May 2021 07:35:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29380 20% habitat loss due to invasion). Upstream invasion by centrarchids isolated and fragmented P. afer populations into headwater refugia, while top down invasion by salmonids excluded B. trevelyani from invaded, more pristine stream reaches, by forcing the species into degraded unsuitable lower stream reaches. Predation also disrupted population processes such as adult dispersal for P. afer, and centrarchid-invaded zones acted as demographic sinks, where adults dispersing through invaded reaches were rapidly depleted. While the Mandela lineage of P. afer exhibited little within or between drainage genetic structuring, B. trevelyani was >4% divergent between drainages, and up to 2% divergent between streams within the Keiskamma River system (Chapter 7). The distribution of genetic diversity for B. trevelyani also indicated that the loss of diversity was imminent without immediate conservation interventions. This thesis has provided conclusive evidence that native fishes are vulnerable to invasion and that non-native predatory fishes have significant impacts on native fishes in Eastern Cape headwater streams. If management and conservation measures are implemented, the unwanted introduction and spread of non-native fishes may be restricted, allowing native fishes opportunities for recovery.]]> Thu 13 May 2021 07:28:56 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:26387 Thu 13 May 2021 07:27:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:38234 Thu 13 May 2021 07:19:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:34282 Thu 13 May 2021 07:18:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28538 Thu 13 May 2021 07:11:33 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30400 Thu 13 May 2021 07:07:53 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28517 Thu 13 May 2021 07:06:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:34163 Thu 13 May 2021 06:59:15 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28644 Thu 13 May 2021 06:58:27 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28089 Thu 13 May 2021 06:56:43 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:34201 0.05 in all cases). Microplastic counts ranged on average from 55 ± 289 to 930 ± 462 microplastic particles.m-3. With the exception of two instances, microfibres constituted > 50 % (range: 47 to 97 %) of the total microplastic counts. Part two of this study assessed the size range of, and seasonal and spatial patterns in ingested microplastic. No significant differences were found in the number of microplastics ingested within seasons between the mussels Perna perna (Linnaeus, 1758) and Mytilus galloprovincialis (Lamarck, 1819), and the barnacles, Octomeris angulosa (Sowerby, 1825) and Tetraclita serrata (Darwin 1954) (Student’s t-test; d.f = 18; p > 0.05 in all cases), or between the two sites sampled, Kenton-on-Sea, Eastern Cape, and Wilderness, Western Cape (ANOVA; d.f. = 18; p > 0.05 in all cases). The nitric acid digestion technique was used to determine the presence of ingested microplastics. Microplastic loads ranged from 2 ± 1 to 33 ± 19 microplastics.g-1 wwt across all consumers, and the size of ingested microplastics ranged from 1 to 16 μm. Though highly variable, the absence of statistically significant differences in ingestion rates points to a ubiquity in the availability of microplastics within the water column over time and space.]]> Thu 13 May 2021 06:52:15 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:34478 Thu 13 May 2021 06:50:15 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27777 Thu 13 May 2021 06:43:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:31318 Thu 13 Apr 2023 15:20:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28307 Thu 11 Apr 2024 19:25:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27998 Thu 06 Apr 2023 13:57:50 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28104 Thu 04 May 2023 09:22:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28149 Thu 04 May 2023 08:33:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:26877 Thu 01 Jun 2023 11:15:19 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28500 Thu 01 Jun 2023 09:02:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28596 Thu 01 Feb 2024 09:56:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27442 Thu 01 Feb 2024 09:48:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:31154 Thu 01 Feb 2024 09:46:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28434 Thu 01 Feb 2024 09:44:06 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57236 Sun 09 Oct 2022 18:49:45 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57234 Sun 09 Oct 2022 18:07:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:38741 Sat 04 Dec 2021 12:41:27 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42937 4. The modeling methods used in the study were artificial neural network (ANN), linear regression (LR) and polynomial functions. The approach taken was to first test the modeling techniques on a single station before expanding the study to cover the regional aspect. The single station modeling was developed based on ionosonde data over Grahamstown. The inputs for the model which related to seasonal variation, diurnal variation, geomagnetic activity and solar activity were considered. For the geomagnetic activity, three indices namely; the symmetric disturbance in the horizontal component of the Earth’s magnetic field (SYM − H), the Auroral Electrojet (AE) index and local geomagnetic index A, were included as inputs. The performance of a single station model revealed that, of the three geomagnetic indices, SYM − H index has the largest contribution of 41% and 54% based on ANN and LR techniques respectively. The average correlation coefficients (R) for both ANN and LR models was 0.8, when validated during the selected storms falling within the period of model development. When validated using storms that fall outside the period of model development, the model gave R values of 0.6 and 0.5 for ANN and LR respectively. In addition, the GPS total electron content (TEC) derived measurements were used to estimate foF2 data. This is because there are more GPS receivers than ionosonde locations and the utilisation of this data increases the spatial coverage of the regional model. The estimation of foF2 from GPS TEC was done at GPS-ionosonde co-locations using polynomial functions. The average R values of 0.69 and 0.65 were obtained between actual and derived _foF2 over the co-locations and other GPS stations respectively. Validation of GPS TEC derived foF2 with RO data over regions out of ionospheric pierce points coverage with respect to ionosonde locations gave R greater than 0.9 for the selected storm period of 4-8 August 2011. The regional storm-time model was then developed based on the ANN technique using the four South African ionosonde stations. The maximum and minimum R values of 0.6 and 0.5 were obtained over ionosonde and GPS locations respectively. This model forms the basis towards the regional ionospheric storm-time index.]]> Mon 31 May 2021 15:12:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28062 Mon 22 May 2023 14:58:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41020 Mon 18 Dec 2023 18:00:37 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42936 Mon 17 May 2021 15:55:32 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42802 Mon 17 May 2021 12:32:33 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41490 Mon 17 Apr 2023 11:28:01 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28492 Mon 10 Oct 2022 14:26:28 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:57256 Mon 10 Oct 2022 09:43:43 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28065 Mon 05 Jun 2023 15:41:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42896 Fri 28 May 2021 11:35:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28305 Fri 23 Jul 2021 12:53:04 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28141 Fri 23 Jul 2021 12:25:01 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28228 Fri 17 Sep 2021 14:51:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28043 Fri 17 Sep 2021 11:42:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:38991 Fri 14 Jul 2023 09:03:33 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41327 Fri 08 Jul 2022 11:49:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28323 Fri 07 Jul 2023 06:57:12 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:26897 Fri 06 Aug 2021 09:57:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42109 80%. The formulation composition identified was subsequently used for the optimization of the manufacturing parameters viz. sonication time and amplitude, using a Central Composite Design (CCD) . The LC and EE, in vitro CLA release, cytotoxicity, osmolarity, pH, degree of crystallinity and lipid modification, elemental analysis and surface morphology of the optimized batch was investigated and mon itored to ensure that CLA - loaded NLC, of the desirable quality, had been produced. On the day of manufacture the mean PS and PDI of the optimized CLA - loaded NLC formulation adjusted to physiological osmolarity (250 – 450 mOsm/kg) was 461.9 ± 40.16 nm and 0. 523 ± 0.104, respectively. The ZP for the optimized NLC generated on the day of manufacture using HPLC grade water as the dispersion medium was - 20.5 ± 4.82 mV. The pH and osmolarity of the optimized CLA - loaded NLC formulation was 7.76 ± 0.01 and 316 ± iii 2 m Osm/Kg, respectively and the EE was 88.62 ± 0.23 %. The optimized NLC exhibited a decreased crystallinity in comparison to the bulk lipid materials. DSC, WAXS and FT - IR revealed that CLA was molecularly dispersed in the nanocarriers. The optimized CLA - load ed NLC exhibited muco - adhesive properties, when tested under stationary conditions using laser doppler anemometry (LDA). The optimized formulation also exhibited sustained release of CLA over 24 hours during in vitro release testing and CLA release was bes t described using the Baker - Lonsdale model . The cumulative % CLA released over 24 hours was 56.13 ± 0.23% and mass balance analysis revealed 41.38 ± 0.02% CLA had been retained in the NLC. In vitro cytotoxicity testing revealed that the optimized CLA - NLC w ere less cytotoxic to HeLa cells when compared to CLA alone and further confirmed that the lipids and excipients used in these studies were of GRAS status . Stability studies revealed that the EE reduced over 28 days by 14.42% and 5.14% when stored at 4 °C and 22 °C , respectively. In addition, the particle size increased from the nm to μm range for samples stored at 22 °C. The findings are a good starting point but require further optimization to ensure prolongation of stability. In addition , the technology requires additional developmental studies and a powder for reconstitution for use as a single - dose considered as single dose packaging may be a solution to the compromised formulation stability observed in these studies. The CLA - NLC produced in these stu dies exhibit sound product attributes which serve as a useful foundation for the novel delivery of antibiotics to the eye. The results suggest that the optimized NLC have the potential to enhance precorneal retention and increase ocular availability of CLA , which in turn may be useful to reduce the required dose and dosing frequency when administering CLA as a reconstituted solution to treat susceptible organisms that infect ocular tissues.]]> Fri 06 Aug 2021 09:14:42 SAST ]]>