Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited p...Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited pH dependant swelling and solute diffusivity due to the formation or disruption of hydrogen bonded complexation between methacrylic acid (MAA) and etheric (EO). In neutral and basic conditions (above the swelling transition pH), the copolymer swelling was greatly higher than acid condition. In complexed hydrogels, the diffusion coefficients of vitamin B12 (VB12) were in the range of 10-10 to 10-7 cm2s-1; While in uncomplexed hydrogels, the values were about 210-6 cm2s-1. The comonomer composition and synthesis conditions have great effect on the structure, and thereby, swelling and solute diffusion characteristics of the resultant hydrogels. For the copolymers with composition of less than or more than 1:1 MAA/EO molar ratio, the plot of lnD vs 1/H-1 followed two different linear equations of 慺ree volume theory? respectively.展开更多
The densities and viscosities of ternary systems(Poloxamer 188+ethanol/acetone+water)were meas- ured at 288.15,293.15,298.15,303.15,308.15 K and atmospheric pressure for different mass fractions of Poloxamer 188(0 to ...The densities and viscosities of ternary systems(Poloxamer 188+ethanol/acetone+water)were meas- ured at 288.15,293.15,298.15,303.15,308.15 K and atmospheric pressure for different mass fractions of Poloxamer 188(0 to 0.02)in aqueous solution and different solvent volume fractions of ethanol/acetone(0 to 0.3)in Poloxamer 188 aqueous solution.The densities were measured by a pycnometer,while the viscosities were measured using two Ubbelohde capillary viscometers.The correlations of density and viscosity of these ternary systems are obtained by fitting the experimental data at different temperatures,mass fractions and volume fractions.展开更多
In the present study,we aimed to probe the possibility of using mixed poloxamers as carriers to prepare ternary solid dispersion(SD)that facilitated solubility and dissolution rate of the poorly water soluble drug and...In the present study,we aimed to probe the possibility of using mixed poloxamers as carriers to prepare ternary solid dispersion(SD)that facilitated solubility and dissolution rate of the poorly water soluble drug and compare with binary SD with single poloxamer.Lidocaine(LIC)was selected as a model drug,and poloxamer 188(P188)and poloxamer 407(P407)were utilized as single and mixed carriers.Depending on DSC and the dissolution testing,the appropriate ratio of SD prepared by melting method was optimized.Ternary and binary SD was characterized by DSC,XRD,SEM and FTIR.In vitro dissolution study,phase solubility study and saturated solubility study were performed to clarify solubilization from apparent phenomena and inherent reason.Moreover,stability study under different relative humidity(RH)was investigated.Physical characterizations of binary and ternary SD exhibited the formation of eutectic mixture and the presence of molecular interaction.Compared with the pure LIC,the dissolution rate and solubility of LIC in binary and ternary SDs were enhanced.The phase solubility study revealed an AL-type curve.Furthermore,the stability test indicated that ternary and binary SD was stable.The results of this study demonstrated that SD with mixed poloxamers could improve dissolution rate and solubility of poorly water-soluble drug.展开更多
In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-f...In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-film hydration method, and its physicochemical properties, including particle size, zeta potential, entrapment efficiency and drug loading, were investigated. In vitro release of genistein from the mixed micelles was monitored by dialysis method, and pharmacokinetic study of genistein loaded mixed micelles was carried out in rats. We found that the particle size and zeta potential of mixed micelles were（20.31±0.43） nm and（–8.94±0.35） m V, with encapsulation efficiency 90.59%±0.67% and drug loading 7.74%±0.05%. Solubility of genistein in mixed micelles reached 3.80 mg/m L, which was about 130 times higher than that in water. Genistein-loaded mixed micelles showed sustained release characteristics in vitro with no burst release phenomenon, but it was faster than suspension. The AUC0–t and AUC0–∞ of mixed micelles were 196.74% and 204.62% greater than that of genisein suspension, respectively. Consequently, poloxamer 403/407 mixed micelles significantly improved the solubility and oral bioavailability of genistein, which could be used as an effective drug delivery system for oral administration of poorly soluble drugs.展开更多
文摘Poly(methacrylic acid co-poloxamer) hydrogel networks were synthesized by free radical solution polymerization and their equilibrium swelling and solute permeation properties were characterized. These gels exhibited pH dependant swelling and solute diffusivity due to the formation or disruption of hydrogen bonded complexation between methacrylic acid (MAA) and etheric (EO). In neutral and basic conditions (above the swelling transition pH), the copolymer swelling was greatly higher than acid condition. In complexed hydrogels, the diffusion coefficients of vitamin B12 (VB12) were in the range of 10-10 to 10-7 cm2s-1; While in uncomplexed hydrogels, the values were about 210-6 cm2s-1. The comonomer composition and synthesis conditions have great effect on the structure, and thereby, swelling and solute diffusion characteristics of the resultant hydrogels. For the copolymers with composition of less than or more than 1:1 MAA/EO molar ratio, the plot of lnD vs 1/H-1 followed two different linear equations of 慺ree volume theory? respectively.
基金Supported by the National Natural Science Foundation of China(20606031)
文摘The densities and viscosities of ternary systems(Poloxamer 188+ethanol/acetone+water)were meas- ured at 288.15,293.15,298.15,303.15,308.15 K and atmospheric pressure for different mass fractions of Poloxamer 188(0 to 0.02)in aqueous solution and different solvent volume fractions of ethanol/acetone(0 to 0.3)in Poloxamer 188 aqueous solution.The densities were measured by a pycnometer,while the viscosities were measured using two Ubbelohde capillary viscometers.The correlations of density and viscosity of these ternary systems are obtained by fitting the experimental data at different temperatures,mass fractions and volume fractions.
基金National Natural Science Fund of China(Grant No.30801552&81274095)the third key project funded by Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization(Grant No.012092002006-10)the 55th postdoctoral project(Grant No.021062001001).
文摘In the present study,we aimed to probe the possibility of using mixed poloxamers as carriers to prepare ternary solid dispersion(SD)that facilitated solubility and dissolution rate of the poorly water soluble drug and compare with binary SD with single poloxamer.Lidocaine(LIC)was selected as a model drug,and poloxamer 188(P188)and poloxamer 407(P407)were utilized as single and mixed carriers.Depending on DSC and the dissolution testing,the appropriate ratio of SD prepared by melting method was optimized.Ternary and binary SD was characterized by DSC,XRD,SEM and FTIR.In vitro dissolution study,phase solubility study and saturated solubility study were performed to clarify solubilization from apparent phenomena and inherent reason.Moreover,stability study under different relative humidity(RH)was investigated.Physical characterizations of binary and ternary SD exhibited the formation of eutectic mixture and the presence of molecular interaction.Compared with the pure LIC,the dissolution rate and solubility of LIC in binary and ternary SDs were enhanced.The phase solubility study revealed an AL-type curve.Furthermore,the stability test indicated that ternary and binary SD was stable.The results of this study demonstrated that SD with mixed poloxamers could improve dissolution rate and solubility of poorly water-soluble drug.
基金The Zhejiang Public Welfare Technology Application Research Project(Grant No.2015C31100)the Ningbo Science and Technology Innovation Team Project(Grant No.2015C110027)
文摘In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-film hydration method, and its physicochemical properties, including particle size, zeta potential, entrapment efficiency and drug loading, were investigated. In vitro release of genistein from the mixed micelles was monitored by dialysis method, and pharmacokinetic study of genistein loaded mixed micelles was carried out in rats. We found that the particle size and zeta potential of mixed micelles were（20.31±0.43） nm and（–8.94±0.35） m V, with encapsulation efficiency 90.59%±0.67% and drug loading 7.74%±0.05%. Solubility of genistein in mixed micelles reached 3.80 mg/m L, which was about 130 times higher than that in water. Genistein-loaded mixed micelles showed sustained release characteristics in vitro with no burst release phenomenon, but it was faster than suspension. The AUC0–t and AUC0–∞ of mixed micelles were 196.74% and 204.62% greater than that of genisein suspension, respectively. Consequently, poloxamer 403/407 mixed micelles significantly improved the solubility and oral bioavailability of genistein, which could be used as an effective drug delivery system for oral administration of poorly soluble drugs.
