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Item Formulation of floating metronidazole microspheres using cassava starch (manihot esculenta) as polymer(Springer Publications, 2017) Odeku, O. A; Aderogba, A. A.; Ajala, T. O.; Akin-Ajani, O. D.; Okunlola, A" Floating gastroretentive microspheres have been used to prolong the gastric residence time after oral administration and improve the local effect of metronidazole in the stomach in the treatment of peptic ulcer caused by Helicobacter pylori. In the present study, cassava starch, obtained from the tubers of Manihot esculenta has been pregelatinized and used as polymer in combination with sodium alginate for the formulation of floating gastroretentive metronidazole microspheres. Metronidazole microspheres were prepared by ionic gelation method using pregelatinized cassava starch and sodium alginate at different concentrations as polymers and calcium chloride (2% w/v) as chelating agent. Sodium bicarbonate (2% w/w) was used as gas releasing agent. Microspheres were characterized using the particle size, swelling index, floating lag time (FLT), total floating time and drug release properties. Spherical discrete microspheres with size ranging from 1.52 to 2.23 mm were obtained with FLT of less than 5min and drug entrapment efficiency of 42–60% w/w. The microsphere maintained buoyancy for over 19h and the microspheres provided controlled release of metronidazolefor up to 18h. Drug release from the microspheres, swelling index and buoyancy depended on the concentration of cassava starch in the polymer blend. Formulations containing high concentration of cassava starch showing shorter floating lag time and faster drug release. Thus, buoyancy and rate of drug release appeared to be modulated by the concentration of cassava starch in the polymer blend. The results showed that pregelatinized cassava could be useful in the formulation of floating gastroretentive metronidazole microspheres "Item Formulation and in vitro evaluation of natural gum-based microbeads for delivery of ibuprofen(Pharmacotherapy group, faculty of pharmacy, university of Benin, Benin City, 2013) Odeku, O. A; Okunlola, A.; Lamprecht, A.Purpose: To investigate the effectiveness of three natural gums, namely albizia, cissus and khaya gums, as excipients for the formulation of ibuprofen microbeads. Methods: Ibuprofen microbeads were prepared by the ionotropic gelation method using the natural gums and their blends with sodium alginate at various concentrations using different chelating agents (calcium chloride, zinc chloride, calcium acetate and zinc acetate) at different concentrations. Microbeads were assessed for their morphology using SEM, swelling characteristics, drug entrapment efficiencies, release properties and drug release kinetics. Results: The natural gums alone could not form stable microbeads in the different chelating agents. Stable small spherical discrete microbeads with particle size of 1.35 ± 0.11 to 1.78 ± 0.11 mm, were obtained using the blends of natural gum: alginate at total polymer concentration of 2% w/v using 10% w/v calcium chloride solution at a stirring speed of 300 rpm. The encapsulation efficiencies of the microbeads ranged from 35.3 to 79.8 % and dissolution times, t15 and t80 increased with increase in the concentration of the natural gums present in the blends. Controlled release was obtained for over 4 h and the release was found to be by a combination of diffusion and erosion mechanisms from spherical formulations. Conclusion: The three natural gums would be useful in the formulation of ibuprofen microbeads and the type and concentration of natural gum in the polymer blend can be used to modulate the release properties of the microbeads.Item Formulation optimization of floating microbeads containingmodified Chinese yam starch using factorial design.(IPEC-Americas Inc., 2012-03) Okunlola, A.; Odeku, O. A; Patel, R. P.Controlled release floating metformin hydrochloride microbeads were prepared and optimized using a blend of varying concentrations of freeze-dried pregelatinized Chinese yam starch (Dioscorea oppositifolia L) and sodium alginate. Floating microbeads were prepared by the ionotropic gelation method using 10% w/v calcium chloride as the cross-linking agent and sodium bicarbonate as the gas releasing agent. A full 32 factorial design was used to investigate the influence of two variables: concentrations of starch (X1) and sodium bicarbonate (X2) on the swelling, floating lag time and amount of drug released after 1 hour (Q1) and 10 hours (Q10). Potential variables such as the concentrations of drug and total polymer were kept constant. The results showed that the properties of the floating microbeads were significantly (p<0.01) affected by the concentration of the modified Chinese yam starch. Buoyancy and drug release appeared to be facilitated by increased concentrations of both starch and sodium bicarbonate in the formulation. The results also show that an optimized formulation of metformin hydrochloride could be obtained with the potential for gastroretentive controlled drug delivery using a blend of freeze-dried pregelatinized Chinese yam starch and sodium alginate.Item Compressional characteristics and tableting properties of starches obtained from four dioscorea species(2009) Okunlola, A; Odeku, O. AThe compressional characteristics and tableting properties of starches from four yam species namely Dioscorea dumetorum Pax (Bitter); Dioscorea oppositifolia L (Chinese); Dioscorea alata L.DIAL2 (Water) and Dioscorea rotundata Poir (White) were Investigated in comparison with corn starch. The physicochemical properties of the starches were evaluated using established methods while the compressional characteristics were analyzed using density measurements, and the Heckel and Kawakita equations. The properties of the tablets were assessed using Tensile strength (T), Brittle Fracture Index (BFI), Friability (F) and Disintegration Time (DT). The physicochemical properties of the starches varied considerably among the various species. The ranking for the mean yield pressure (Py) obtained from Heckel plots was Chinese > Bitter>Corn > White>Water while the ranking was the reverse for another pressure term, Pk, obtained from Kawakita plots. The ranking for T was Chinese > Bitter>Corn > White>Water. The T values were inversely related to Pk values. The ranking of DT was Bitter>Chinese>Corn>White> Water, while the ranking was reverse for BFI and F. Water and White yam starch tablets did not conform to the Pharmacopoeia requirements on friability (≤1%) while all the starch tablets except Bitter yam starch conformed to the requirements on disintegration (≤15minutes). Thus, the starches could be useful as excipients in tablet formulations.Item Formulation factors affecting the binding properties of chinese yam (dioscorea oppositifolia) and corn starches(Elsevier, 2009) Okunlola, A.; Odeku, O. AObjective; The quantitative effects of formulation and processing variables affecting the binding properties of Chinese yam starch ( Dioscorea oppositifolia) in chloroquine phosphate tablet formulations have been investigated in comparison with com starch using a 23 factorial experimental design. Methods: Chinese yam starch, representing the "low" level, and com starch, representing the "high" level were used as binders at concentrations of 2. 5 % w/w and 10 % w/w in chloroquine phosphate tablet formulations. The mechanical properties of the tablets, measured by the tensile strength ( T ) and brittle fracture index ( BFI) as well as the release properties measured by the disintegration time (DT ) and dissolution time ( t80- time for 80 % drug release) , were used as assessment parameters. Results; The ranking of the individual coefficient values for the formulations on T was D > N » C , on BFI was N > D » C , on DT was D > N > C and on t80 was C > N > D while the ranking of the interaction coefficient on T was N-D > C-D » N-C, on BFI was N-D > N-C = C-D, on DT and t80 was N-C > N-D > C-D. Changing the binding agent from Chinese to corn starch, led to a decrease in T , DT and t80 but increase in BFI of the tablets. There were significant (P < 0 . 001) interactions between the nature of binder, N and the other two variables, C and D. Conclusion; The result showed that Chinese yam possessed stronger binding capacity than corn starch and could be useful as an alternative binder when tablets with high mechanical strength with minimal problems of lamination, and slow release are required.