Microencapsulation of ibuprofen and Eudragit 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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ABSTRACT: The present study is a preliminary exploration of the affinity between a carboxylic model drug, the nonsteroidal antiinflammatory agent ibuprofen (IBU) and Eudragit RL100 (RL) polymer. Due to the presence of a variable amount of quaternary ammonium groups in this matrix, physical and chemical interaction with the carboxylic drug can occur, which reinforces its scant mechanical dispersion in the polymer network and can ultimately affect its release profile in vitro and in vivo. To study these aspects, IBU was mixed at increasing weight ratios and in different chemical forms (free acid, sodium salt, and n-butyl ester), to investigate further the role of the carboxylic group in the interaction with the RL polymer. Therefore, IBU-RL solid dispersions (coevaporates) were obtained and fully characterized in the solid state through spectroscopic, calorimetric, and x-ray diffractometric analyses. The in vitro release pattern of the drug, in the different chemical states, was studied for the coevaporates, compared with drug-RL physical mixtures, along with drug adsorption profiles from aqueous solutions on the surface of the polymer granules.Drug Development and Industrial Pharmacy 04/2004; 30(3):277-88. · 1.54 Impact Factor
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ABSTRACT: Objective: To microencapsulate diltiazem hydrochloride (DH) drug-resin to obtain obvious sustained release effect in vitro and in vivo. Methods: The drug-resinates were made by bath method. The drug-resinates microcapsules were prepared with the ratio of the concentration of coating materials being 1% and the ratio of drug-resin complexes to coating materials being 10:1 by emulsion-solvent diffusion method. The pharmacokinetic of the sustained-release DH microspheres in beagle dogs was carried out. Results: The microencapsulated ion-exchange resin beads containing DH showed sustained-release characteristics for 12 h and exhibited complete release. The pharmacokinetics parameters of DH sustained-release microspheres and reference tablet was AUC0-24 (ng·h·mL(-1)) 836.3 and 857.3, C(max) (ng·mL(-1)) 85.4 and 135.2, T(max) (h) 4.7 and 1.2. Conclusion: The mononucleated microencapsulated ion-exchange resin beads showed obvious sustained release character in vitro. The pharmacokinetic of the DH microspheres showed that the test dosage forms were bioequivalent with reference dosage form and had an obviously sustained release effect in vivo.Drug Development and Industrial Pharmacy 02/2012; · 1.54 Impact Factor
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ABSTRACT: In the present study microspheres containing felodipines were prepared by Solvent evaporation method and characterized by optical microscopy and scanning electron microscopy. The microspheres were analyzed for drug entrapment, bulk density, angle of repose, particle size and In-vitro release pattern. The effect of process variables on microsphere size was studied and based on these preliminary studies, different batches of microspheres were prepared by altering the drug: polymer ratio and cross-linking with calcium chloride. The size of microspheres was in range of 130-140µm. They were spherical in shape as evidenced by photomicrographs and scanning electron microscopy. The percent drug entrapment was in the range of 86-88 % and they could sustain drug release over a period of 8 hrs.International Journal of Pharmaceutical Research & Development. 04/2009; 3(3):23-26.