Partial least squares(PLS),back-propagation neural network(BPNN)and radial basis function neural network(RBFNN)were respectively used for estalishing quantative analysis models with near infrared(NIR)diffuse r...Partial least squares(PLS),back-propagation neural network(BPNN)and radial basis function neural network(RBFNN)were respectively used for estalishing quantative analysis models with near infrared(NIR)diffuse reflectance spectra for determining the contents of rifampincin(RMP),isoniazid(INH)and pyrazinamide(PZA)in rifampicin isoniazid and pyrazinamide tablets.Savitzky-Golay smoothing,first derivative,second derivative,fast Fourier transform(FFT)and standard normal variate(SNV)transformation methods were applied to pretreating raw NIR diffuse reflectance spectra.The raw and pretreated spectra were divided into several regions,depending on the average spectrum and RSD spectrum.Principal component analysis(PCA)method was used for analyzing the raw and pretreated spectra in different regions in order to reduce the dimensions of input data.The optimum spectral regions and the models' parameters were chosen by comparing the root mean square error of cross-validation(RMSECV)values which were obtained by leave-one-out cross-validation method.The RMSECV values of the RBFNN models for determining the contents of RMP,INH and PZA were 0.00288,0.00226 and 0.00341,respectively.Using these models for predicting the contents of INH,RMP and PZA in prediction set,the RMSEP values were 0.00266,0.00227 and 0.00411,respectively.These results are better than those obtained from PLS models and BPNN models.With additional advantages of fast calculation speed and less dependence on the initial conditions,RBFNN is a suitable tool to model complex systems.展开更多
Novel poly(lactide-co-glycolide acid)(PLGA) microspheres were developed for sustained delivery of antisense oligonucleotide(ASO). First, a new cationic agent, polyethylenimine(PEI) conjugated to linoleic acid...Novel poly(lactide-co-glycolide acid)(PLGA) microspheres were developed for sustained delivery of antisense oligonucleotide(ASO). First, a new cationic agent, polyethylenimine(PEI) conjugated to linoleic acid(LA)(PEI-LA) was synthesized by reacting PEI(Mw=800) with linoleoyl chloride. Then, PEI-LA was combined with LOR-2501 to form electrostatic complexes at moderate nitrogen-to-phosphate(N/P) molar ratios which were then encapsulated into poly(lactide-co-glycolide) microspheres by a multiple emulsion-solvent evaporation technique. With an increase in ASO/PEI-LA concentration from 5% to 10%, encapsulation efficiency of ASO in the micro- spheres reduced from 72.14% to 57.62%, and the particle size ofmicrospheres increased from 28.58 μm to 34.76 μm. In vitro studies show that the release profile of ASO from microspheres prepared at 7.5% ASO-PEI-LA lasted for 14 d The novel microspheres have a potential use as a sustained release vehicle for ASO.展开更多
基金Supported by the Science Technology Development Project of Jilin Province,China(No.20020503-2).
文摘Partial least squares(PLS),back-propagation neural network(BPNN)and radial basis function neural network(RBFNN)were respectively used for estalishing quantative analysis models with near infrared(NIR)diffuse reflectance spectra for determining the contents of rifampincin(RMP),isoniazid(INH)and pyrazinamide(PZA)in rifampicin isoniazid and pyrazinamide tablets.Savitzky-Golay smoothing,first derivative,second derivative,fast Fourier transform(FFT)and standard normal variate(SNV)transformation methods were applied to pretreating raw NIR diffuse reflectance spectra.The raw and pretreated spectra were divided into several regions,depending on the average spectrum and RSD spectrum.Principal component analysis(PCA)method was used for analyzing the raw and pretreated spectra in different regions in order to reduce the dimensions of input data.The optimum spectral regions and the models' parameters were chosen by comparing the root mean square error of cross-validation(RMSECV)values which were obtained by leave-one-out cross-validation method.The RMSECV values of the RBFNN models for determining the contents of RMP,INH and PZA were 0.00288,0.00226 and 0.00341,respectively.Using these models for predicting the contents of INH,RMP and PZA in prediction set,the RMSEP values were 0.00266,0.00227 and 0.00411,respectively.These results are better than those obtained from PLS models and BPNN models.With additional advantages of fast calculation speed and less dependence on the initial conditions,RBFNN is a suitable tool to model complex systems.
基金Supported by the National Natural Science Foundation of China(Nos.30870251, 31070309).
文摘Novel poly(lactide-co-glycolide acid)(PLGA) microspheres were developed for sustained delivery of antisense oligonucleotide(ASO). First, a new cationic agent, polyethylenimine(PEI) conjugated to linoleic acid(LA)(PEI-LA) was synthesized by reacting PEI(Mw=800) with linoleoyl chloride. Then, PEI-LA was combined with LOR-2501 to form electrostatic complexes at moderate nitrogen-to-phosphate(N/P) molar ratios which were then encapsulated into poly(lactide-co-glycolide) microspheres by a multiple emulsion-solvent evaporation technique. With an increase in ASO/PEI-LA concentration from 5% to 10%, encapsulation efficiency of ASO in the micro- spheres reduced from 72.14% to 57.62%, and the particle size ofmicrospheres increased from 28.58 μm to 34.76 μm. In vitro studies show that the release profile of ASO from microspheres prepared at 7.5% ASO-PEI-LA lasted for 14 d The novel microspheres have a potential use as a sustained release vehicle for ASO.