Physico-Chemical Characterization and Evaluation of Two Local Cactus Mucilages (Opuntia Spp.) as Suspending Agents
| dc.contributor.advisor | Gebre-Mariam, Tsige (Professor) | |
| dc.contributor.author | G/Samuel, Naod | |
| dc.date.accessioned | 2018-06-14T22:25:15Z | |
| dc.date.accessioned | 2023-11-06T08:09:03Z | |
| dc.date.available | 2018-06-14T22:25:15Z | |
| dc.date.available | 2023-11-06T08:09:03Z | |
| dc.date.issued | 2010-05 | |
| dc.description.abstract | Ethiopia is one of the countries where cactus grows naturally. Cactus pear (Opuntia spp.), Cactaceae family, is a plant with an impressive genetic diversity of over 400 species. Cactaceae are well adapted to arid and hot drylands, where the plants have a marked capacity to withstand prolonged drought. The peculiar feature of the plant to adapt such areas is because of the presence of mucilage in specialized cells of the cladodes. Mucilage is a complex carbohydrate with a highly branched structure, which contains varying proportions of L-arabinose, Dgalactose, L-rhamnose and D-xylose, as well as galacturonic acid in different proportions. It swells in water and form viscous mass. Hence, recently an attention is being paid for its potential use in industry: food, cosmetic and pharmaceutical sectors. The objective of this study is to determine the physico-chemical properties of mucilages of Opuntia ficus-indica and Opuntia stricta, the two most abundant cactus species in Ethiopia, and evaluate their suspending ability in pharmaceutical suspensions. The physico-chemical properties of the mucilages were compared between themselves. The suspending abilities of the mucilages were compared with NaCMC. The dissolutions of the suspensions were performed using the USP paddle method at 25 rpm. The yield of mucilage from both Opuntia spp. was found to be comparable. The solubility and SP of the mucilages were also studied. With increase in temperature the solubility increased and was comparable in both mucilages. However, at all the treatment levels the SP were higher in mucilage of OS than that of OFI the differences of which were statistically significant. At 100% RH the moisture sorption property of OFI and OS were 95.4% and 76.9%, respectively. The pH values of both mucilages were found to decrease upon increasing mucilage concentration which at 12% (w/v) dispersions were 5.57 and 5.87 for OFI and OS, respectively. The results showed that these pH values are to be classified within low acid group. The conductivity, at 12% (w/v), of OFI was found to be 13.12 mS/cm while that of OS was 9.31 mS/cm. The apparent viscosities at 12% (w/v) were 9,017 mPas and 10,060 mPas for OFI and OS, respectively. The apparent x viscosities of the dispersions decreased with increase in shear rates which rendered the dispersions a pseudoplastic flow. These physico-chemical properties of the mucilages can signal on their potential use in pharmaceutical formulations especially suspensions. Hence, Paracetamol suspensions using the mucilages and NaCMC as suspending agents were formulated. The apparent viscosities of the suspensions in all the suspending agents concentration levels and applied shear rates were in the order of NaCMC>OS>OFI with non-Newtonian flow and accordingly the flow rates of the suspensions were in the order of OFI>OS>NaCMC. The sedimentation volumes (%) of the suspensions in all the suspending agent concentration levels were higher for OS followed by OFI and then NaCMC. The high sedimentation volumes (%) of suspensions, in turn, were accompanied by ease of redispersibility of that order. The effect of electrolyte on sedimentation volume (%) had dual effect. It was only the suspensions that had NaCMC that showed increase in sedimentation volume (%) in all molar NaCl concentration. However, in suspensions that had mucilages of OS and OFI, an initial increase in sediment volumes (%) were accompanied by decrease after 1x10-3M and 1x10-2M of NaCl, respectively. Moreover, the effect of pH on sedimentation volume (%) was addressed. Hence, the suspensions from NaCMC were stable in acidic media while suspensions from OFI and OS were stable in basic media. Dissolution of the suspensions which had mucilages attained the acceptable ranges (≥ 80% drug release in 30 min) in 5 min. Similarly, except A6 formulations A2, A3, A4 and A5 have attained the limit but the release was not as quick as the previous formulations. Hence, it can be concluded that mucilages of Opuntia spp. (Opuntia ficus-indica and Opuntia stricta) can be used as alternatives to NaCMC as suspending agent in suspension formulations. Key words: Cactus, Mucilage, Opuntia spp., Sedimentation volume, Suspension, Suspending agent | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/1019 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Cactus, Mucilage; Opuntia spp.; Sedimentation volume; Suspension; Suspending agent | en_US |
| dc.title | Physico-Chemical Characterization and Evaluation of Two Local Cactus Mucilages (Opuntia Spp.) as Suspending Agents | en_US |
| dc.type | Thesis | en_US |