Microencapsulation of ibuprofen and Eudragit (R) RS 100 by the emulsion solvent diffusion technique
Department of Pharmacy, University of Durban-Westville, Private Bag X54001, 4000, Kwazulu-Natal, Durban, South Africa. International Journal of Pharmaceutics
(Impact Factor: 3.65).
06/2001; 218(1-2):1-11. DOI: 10.1016/S0378-5173(00)00686-4
The emulsion solvent diffusion was employed to prepare modified release microspheres of ibuprofen. The technique was optimised for the following processing variables: the absence/presence of baffles in the reaction vessel, agitation rate and drying time. Thereafter, the influence of various formulation factors on the microencapsulation efficiency, in vitro drug release and micromeritic properties was examined. The variables included the methacrylic polymer, Eudragit(R) RS 100, ibuprofen content and the volume of ethanol used during microencapsulation. The results obtained were then interpreted on a triangular phase diagram to map the region of microencapsulation, as well as those formulations that yielded suitable modified release ibuprofen microspheres.
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- "The homogenization speed affects the dispersion of the emulsifier, which helps form stable nanocapsules, nanoemulsions or micelles. Low emulsifier dispersion leads to a large particle size and heterogeneous size distribution (Kim et al., 2012; Perumal, 2001; Surassmo et al., 2010). "
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ABSTRACT: The effect of trans-cinnamaldehyde emulsions were studied by observing physical and microbial properties. Moreover, trans-cinnamaldehyde emulsions were applied into real food system like watermelon juice. Nano-sized (<200nm) trans-cinnamaldehyde emulsions were produce by using optimum mass ratio of trans-cinnamaldehyde and Tween®20 (1:3) and then high-energy emulsification (10,000rpm high speed homogenization and 20,000 psi high pressure homogenization) was carried out. Trans-cinnamaldehyde was encapsulated as over 70% efficiency and its encapsulation efficiency was maintained higher at 0.8wt% trans-cinnamaldehyde emulsions. For the antibacterial activity results, 0.8wt% trans-cinnamaldehyde emulsions which lowest concentration showed inhibition of Salmonella Typhimurium and Staphylococcus aureus except Escherichia coli growth at both pure water and water melon juice.
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- "Second, alginate possesses mucoadhesive properties which could increase the contact time between microcapsules and absorptive sites, and therefore, could enhance the uptake of encapsulated drug (Guan et al., 2001). Third, biodegradable alginate microcapsules may show variable release kinetics (Perumal, 2001). Fourth, the low toxicity and low immunogenicity of alginate make this polymer a safe matrix (Chan et al., 2002). "
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ABSTRACT: Emulsification/internal gelation has been suggested as an alternative to extrusion/external gelation in the encapsulation of several compounds including non-steroidal anti-inflammatory drugs such as diclofenac sodium. The objective of the present study was a trial to formulate diclofenac sodium as controlled release microparticles that might be administered once or twice daily. This could be achieved via emulsification/internal gelation technique applying Box-Behnken design to choose these formulae. Box-Behnken design determined fifteen formulae containing specified amounts of the independent variables, which included stirring speed in rpm (X1), drug:polymer ratio (X2) and the surfactant span 80% (X3). The dependent variables studied were cumulative percent release after two hours (Y1), four hours (Y2) and eight hours (Y3). The prepared microparticles were characterized for their production yield, sizes, shapes and morphology, entrapment efficiency and Diclofenac sodium in vitro release as well. The results showed that the production yield of the prepared diclofenac sodium microparticles was found to be between 79.55% and 97.41%. The formulated microparticles exhibited acceptable drug content values that lie in the range 66.20-96.36%. Also, the data obtained revealed that increasing the mixing speed (X1) generally resulted in decreased microparticle size. In addition, scanning electron microscope images of the microparticles illustrated that the formula contains lower span concentration (1%) in combination with lower stirring speed (200 rpm) which showed wrinkled, but smooth surfaces. However, by increasing surfactant concentration, microspheres' surfaces become smoother and slightly porous. Kinetic treatment of the in vitro release from drug-loaded microparticles indicated that the zero order is the drug release mechanism for the most formulae.
Available from: Janos Gyenis
- "Certain biologically tolerable synthetic polymers such as polyacrylate copolymers (Eudragit), polycaprolactones, polyaspartamides, or polyamidoamines are also eligible. Perumal  studied the effect of formulation parameters and the technical design of reaction vessel on the properties of microspheres prepared from the ibuprofen model drug and a methacrylic polymer Eudragit® RS 100. Applying side baffles along the circumference of the vessel considerably improved the particle size attributes (lower mean size, narrower size distribution and more regular shape) and the yield of microspheres. "
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ABSTRACT: Combined precipitation and spherical agglomeration was carried out in the non-miscible region of ethyl acetate–ethanol–water ternary solvent system. At first, w/o type quasi emulsion was prepared by sequential introduction of aqueous solutions of human serum albumin (HSA), chitosan (CS), and poly(4-styrenesulfonate) (PSS) into an ethyl acetate–ethanol solvent mixture. HSA was used to model a protein type drug, while CS and PSS served as matrix material in the obtained composite particles. PSS also served as chemical precipitation agent for both of the HSA and CS. The solubility of all these substances was reduced by introduction of additional amounts of ethyl acetate–ethanol mixture and/or ethanol as poor solvents. Due to the counter-diffusion of the good and poor solvents between the water rich droplets and the ethyl acetate–ethanol rich continuous phase, the aqueous phase gradually disappeared and partial agglomeration of the precipitated solids and their transfer to the continuous organic phase took place. The paper gives a report on the effect of several process variables on the quality of the obtained microparticles, such as their shape and stability against disintegration. The effects of the composition of the ternary solvent mixture, the route of its variation, the feeding method and composition of the added poor solvents, the stirring rate and the duration of agitation were studied.
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