Microencapsulation of ibuprofen and Eudragit (R) RS 100 by the emulsion solvent diffusion technique
ABSTRACT 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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- "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. "
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.Powder Technology 08/2013; 244:16–25. DOI:10.1016/j.powtec.2013.03.052 · 2.27 Impact Factor
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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). "
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.Saudi Pharmaceutical Journal 01/2013; 21(1):61-9. DOI:10.1016/j.jsps.2011.08.004 · 1.00 Impact Factor
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- "The emulsion solvent evaporation method may be employed to prepare microcapsules of water insoluble drugs within water insoluble polymers (Beck et al., 1979). Micro encapsulation techniques have been employed to make sustained drug delivery system of IBN (Pralhad and Rajendrakumar, 2004; Perumal, 2001; Valot et al., 2009; Aerts et al., 2010; Bolourtchian et al., 2005). Similarly, different methods have also been employed to prepare stable and sustained drug delivery system of MIS (Oth et al., 1992). "
ABSTRACT: The current study was aimed to develop a stable sustained release drug delivery system for ibuprofen and a cytoprotective agent misoprostol in a combined dosage form. Non-aqueous emulsion solvent evaporation method was used to prepare ibuprofen microspheres. Ethylcellulose (EC) and Hydroxypropyl methylcellulose ( HPMC) were used as the release retarding polymers in combination. Ibuprofen microspheres were prepared separately and then compressed into tablet dosage forms with misoprostol dispersions in HPMC. For surface topography of microspheres, Scanning Electron Microscope (SEM) was used. Fourier transformed infrared (FTIR) spectroscopy and X-ray diffractometry (XRD) were employed to evaluate pharmaceutical incompatibility and physical state of drug in formulation. The mechanism and pattern of drug release were determined by applying kinetic models. Tableted microspheres were also assessed for accelerated stability study for three months. SEM showed spherical shape microspheres. FTIR and XRD data for developed formulation indicated stability and compatibility of drugs with excipients. After 10 h, 86.97 and 89.33% of ibuprofen and misoprostol were released from micro particles while 75.43 and 77.65% from tableted microspheres, respectively. Non-aqueous emulsion solvent evaporation was found to be a suitable method to prepare stable sustained release tableted microspheres of ibuprofen and misoprostol in combination.African journal of pharmacy and pharmacology 09/2012; 6(36):2613-2620. DOI:10.5897/AJPP12.349 · 0.84 Impact Factor