ABSTRACT
The premise of the study was to develop and optimize multiple unit gastroretentive microspheres of itraconazoleto prolong its localization in the stomach and analyzed using response surface methodology. The emulsion solventdiffusion evaporation method was used to prepare hollow microsphere of ethyl cellulose and Eudragit RS100 as lowdensity shell-forming polymers. The experimental design matrix was prepared using a central composite design tostudy the effect of various process parameters over response variables. The optimized microspheres showed a particlesize of 285.1µm, drug entrapment efficiency of 86.8%, buoyancy of 51.1%, and cumulative drug release of 77.80%.The experimental responses were in good harmony with the predicted values. The compatibility between drug andexcipients was determined by Fourier-transform infrared and differential scanning calorimetry analysis. The resultssignify that gastroretentive hollow microspheres are a promising vehicle to extend the retention time of itraconazolein the upper GI tract, and it can be floated in an acidic medium for a prolonged period.
ABSTRACT
Objective:To prepare and optimize sorafenib-Eudragit RS nanoparticles( S-E üPs)and investigate the physicochemi-cal properties. Methods:S-E üPs were prepared by a solvent-nonsolvent method. Single factor experiments were used to research the effect of solvent,stabilizer type,carrier ratio and the proportions of water phase and organic phase on the physicochemical properties of S-E üPs. S-E üPs were evaluated by the particle size,zeta potential and morphology,and the in vitro drug release of S-E üPs was studied using dialysis technology. Results:The mean size was(86. 72 ± 3. 71)nm,the PDI and zeta potential was(0. 20 ± 0. 032)and (36. 6 ± 0. 3)mV,respectively,S-E üPs showed spherical shape with uniform distribution. The drug release in vitro was accorded with a Weibull equation. Conclusion:The solvent-nonsolvent method is appropriate for the preparation of S-E üPs. The nanoparticles have small particle size,uniform distribution,regular morphology and significant sustained-release property.
ABSTRACT
The objective of this research work was to prepare a chrono- modulated drug delivery system to meet chronopharmacological needs of asthma. In this study doxofylline was selected as a model drug. To meet this objective an initial lag phase of release for 3-5 hrs and later a rapid (surge) release phase was considered. To achieve surge release a rapidly releasing core tablet of doxofylline was developed by admixing doxofylline with effervescent granules and super disintegrants. The lag phase in release (2hr) was achieved by coating EV core tablets with release retarding polymers Eudragit RS-100 6% containing HPMC (Hydroxy Propyl Methyl Cellulose) 5%, further over coated with enteric polymer CAP (Cellulose Acetate Phthalate) 12%. The formulated chronomodulated tablets of doxofylline were able to release more than 90% drug within 4 hrs after the lag phase of 2 hrs.
ABSTRACT
Microspheres ketoprofen (KP) were prepared by o/w emulsion solvent evaporation technique using Eudragit®RS100 as a polymeric material. The effect of process variables such as drug: polymer ratio, stirring rate, emulsifier concentration, internal organic solvent and dispersing medium volumes were examined. The prepared formulations were characterized for particle size distribution, percent yield, entrapment efficiency, in vitro release and in vivo studies behavior. The study revealed that the mean particle size ranged from 293.06 to 438.63 μm, the KP loading efficiency varied from 60.19-87.63% of the theoretical amount incorporated, all microspheres patches exhibited a prolonged release for almost 24 hrs and the release pattern was diffusion model. The pharmacokinetic parameters, Cmax, Tmax, AUC0-24 and AUC0-∞ were calculated from the plasma drug concentration-time data. Plasma KP concentrations and pharmacokinetics parameters were statistically analyzed. The test formulation exhibited controlled and prolonged absorption (Tmax) of 6.79 ± 0.0.39 vs. 2.03 ± 0.08 and 3.32 ± 0.24 hs; Cmax of 14.42 ± 0.50 vs. 18.78 ± 0.95 and 16.58 ± 1.02 μg/ml) when compared to the plain drug and marketed product, respectively. In-vivo studies revealed that the relative bioavailability of the KP increased by more than 1.3 times by formulating it into microspheres compared to plain drug.
ABSTRACT
OBJECTIVE: To obtain sustained-release indomethacin PLGA/Eudragit RS 100 microspheres for ophthalmic application and to evaluate its quality. METHODS: The microspheres were prepared by O/W solvent evaporation using PLGA and Eudragit RS 100. The morphological, drug content, entrapment efficiency, release behavior, particle size, residual organic solvent, Zeta potential of indomethacin PLGA/Eudragit RS 100 microspheres were determined; meanwhile, the cytotoxicity of blank microspheres was evaluated using PRE cells. RESULTS: Indomethacin microspheres containing PLGA and Eudragit RS 100 at the weight ratio of 1: 3 had even particle size distribution, and their surfaces were smooth under scan electronic microscope; and the mean diameters were (1676.4 ± 739.5) nm. The drug content and entrapment efficiency of the microspheres were (18.79 ± 0.19)% and (98.25 ± 2.11)%, respectively. Indomethacin was released slowly for a month from the microspheres, though burst release was observed within 24 h. The mean residual organic solvent was (267.33 ± 13.57) ppm. The zeta potential of all blank PLGA / Eudragit RS 100 microspheres was positive. The blank microspheres showed no sign of toxicity. CONCLUSION: Indomethacin PLGA / Eudragit RS 100 microspheres have a better clinical application prospect due to its high entrapment efficiency, narrow distribution, slow release and ocular safety. Copyright 2012 by the Chinese Pharmaceutical Association.
ABSTRACT
Objective To prepare totel glucosides in paeony(TGP) pellets by extrusion-spheronization and to optimize the formulation of TGP sustained-release pellets coated with Eudragit RS 100.Methods The TGP sustained-release pellets were prepared by mini Glatt fluidized bed coating method.The factors to influence the drug release behaviors and their properties were evaluated.Results The optimal TGP sustained-release pellet was shown significant sustained-releasing at the loading weight of copolymers of 6% and the plasticizer concentration of 10%.And the curves of cumulative drug release were fit for Peppas and Higuchi equation.Conclusion The pellets showed an obviously sustained-release effect.