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1.
In order to reduce the crystallinity of PEG 6000, blends were prepared by spray drying and extrusion with the following polymers; PVP K25, PVPVA 64, and HPMC 2910 E5. The maximal reduction of crystallinity in PEG 6000 was obtained by co-spray drying with HPMC 2910 E5. In the next step the model drug Itraconazole was added to the blend and the resulting ternary solid dispersions were characterized. The results of this study show that the addition of PEG 6000 to the Itraconazole/HPMC 2910 E5 system leads to phase separation that in most cases gives rise to recrystallization of either PEG 6000 or Itraconazole. For all ternary dispersions containing 20% of Itraconazole the drug was highly amorphous and the dissolution was improved compared to the binary 20/80 w/w Itraconazole/HPMC 2910 E5 solid dispersion. For all ternary dispersions containing 40% of Itraconazole, the drug was partially crystalline and the dissolution was lower than the dissolution of the binary 40/60 w/w Itraconazole/HPMC 2910 E5 dispersion. These results show that provided Itraconazole is highly amorphous the addition of PEG 6000 to HPMC 2910 E5 leads to an increase in drug release.  相似文献   

2.
In order to understand the influence of temperature and moisture, polymer blends of polyethyleneglycol 6000 (PEG 6000) and hydroxypropylmethylcellulose 2910 E5 (HPMC 2910 E5) and solid dispersions of itraconazole in these polymer blends were spray dried, further dried for 2 weeks and stored at three different conditions: 25 degrees C, 0% relative humidity (RH); 25 degrees C, 52% RH; 60 degrees C, 0% RH. MTDSC analysis of the polymer blends revealed that at 25 degrees C, 52% RH, PEG 6000 recrystallized to a high extent. At 60 degrees C, 0% RH the two polymers were miscible, probably due to the removal of bound water. In the ternary dispersions the polymers behaved similarly. The crystallinity degree of itraconazole in samples stored at 25 degrees C, 52% RH and at 60 degrees C, 0% RH was increased compared to the samples stored at 25 degrees C, 0% RH, probably due to the plasticizing effect of moisture at 25 degrees C, 52% RH and to an increased mobility at 60 degrees C, 0% RH. XPS analysis revealed a redistribution of itraconazole at the surface as itraconazole recrystallized from the blend. Dissolution tests revealed that a decrease in the itraconazole release was directly related to its crystallinity degree, no correlation was found with the crystallinity degree of PEG 6000.  相似文献   

3.
Solid dispersions containing different ratios of itraconazole and hydroxypropylmethylcellulose (HPMC) were prepared by solvent casting. Based on dose, differential scanning calorimetry and dissolution results, a drug/polymer ratio of 40/60 w/w was selected in order to prepare dispersions by melt extrusion. The melt extrusion process was characterized using a design of experiments (DOE) approach. All parameter settings resulted in the formation of an amorphous solid dispersion whereby HPMC 2910 5 mPas prevents re-crystallization of the drug during cooling. Dissolution measurements demonstrated that a significantly increased dissolution rate was obtained with the amorphous solid dispersion compared to the physical mixture. The outcome of DOE further indicated that melt extrusion is very robust with regard to the itraconazole/HPMC melt extrudate characteristics. Stability studies demonstrated that the itraconazole/HPMC 40/60 w/w milled melt extrudate formulation is chemically and physically stable for periods in excess of 6 months as indicated by the absence of degradation products or re-crystallization of the drug.  相似文献   

4.
The good compatibility between Itraconazole and polyvidone-vinylacetate 64 (PVPVA 64) was pointed out previously. However, the dissolution properties of these systems left room for improvement. Therefore polyethylene glycol 6000 (PEG 6000), known for its solubilizing and wetting properties, was added to the PVPVA 64 matrix. Physicochemical analysis showed that up to 10% of PEG 6000 could be mixed with PVPVA 64. Addition of 10%, 20% or 40% of Itraconazole rendered amorphous solid dispersions consisting of a ternary mixed phase and a PVPVA 64 rich amorphous phase. If the PEG 6000 fraction was elevated up to 25% of the carrier, the PEG 6000 crystallinity degree was around 73+/-0.6%. Up to 20% of Itraconazole could be molecularly dispersed in the 25/75 w/w polymer blend. An Itraconazole melting peak could be detected for the sample containing 40% of drug. Dissolution experiments showed that no benefit was obtained by adding PEG 6000 to the PVPVA 64 matrix for samples containing up to 20% of Itraconazole. The dissolution of the ternary dispersions with 40% of Itraconazole on the other hand showed improvement compared to binary Itraconazole/PVPVA 64 dispersions.  相似文献   

5.
The effect of complexation of glimepiride, a poorly water-soluble antidiabetic drug, with β-cyclodextrin and its derivatives (HP-β-CyD and SBE-β-CyD) in presence of different concentrations of water-soluble polymers (HPMC, PVP, PEG 4000 and PEG 6000) on the dissolution rate of the drug has been investigated. The results revealed that the dissolution rate of the drug from these ternary systems is highly dependent on polymer type and concentration. The dissolution rate of the drug from ternary systems containing PEG 4000 or PEG 6000 seems to be generally higher than from systems containing HPMC or PVP. An optimum increase in the dissolution rate of the drug was observed at a polymer concentration of 5% for PEG 4000 or PEG 6000 and at 20% concentration of HPMC or PVP. The dissolution rate of the drug from the ternary system glimepiride–HP-β-CyD–5% PEG 4000 was high compared to the other systems. Tablets containing the drug or its equivalent amount of this ternary system were prepared and subjected to accelerated stability testing at 40 °C/75% R.H. to investigate the effect of storage on the chemical stability as well as therapeutic efficacy of the tablets. The results revealed stability of the tablets and consistent therapeutic efficacy on storage.  相似文献   

6.
Solid dispersion formulations made up of d-alpha-tocopheryl polyethylene glycol succinate 1000 (TPGS 1000) and polyvinyl pyrrolidone co-vinyl acetate 64 (PVPVA 64) or hydroxy propyl methyl cellulose 2910 (HPMC 2910) were developed in order to improve the dissolution of UC 781. UC 781 dissolution rate was markedly improved as compared to the physical mixtures and the pure drug, attaining maximum drug releases of up to 100% after only 5 min in the case of TPGS 1000-UC 781-PVPVA 64 solid dispersions and 30 min in TPGS 1000-UC 781-HPMC 2910. The increased UC 781 dissolution rate could be maintained when formulating UC 781 in PVPVA 64 tablets. The latter disintegrated in only 4 min, reaching drug releases of up to 90% (w/w). In addition, as opposed to the corresponding solid dispersions, no decrease in drug release occurred upon dissolution of PVPVA 64 tablets when the pH was increased to 6.8. Contrary to the PVPVA 64 tablet formulations, HPMC 2910 tablets showed a slow dissolution process due to the gelling nature of the polymer. The drug was slowly released as HPMC 2910 dissolved in the medium, however also in this case 90% (w/w) of the drug was dissolved after 4 h. Both polymers formed compatible blends in combination with the drug. Thermal analysis of the ternary mixtures revealed eutectic behavior exhibiting an extremely fine dispersion of the drug in the carrier. This was confirmed by the fact that no drug crystals could be detected using X-ray diffraction (XRD). As opposed to the physical mixtures, PVPVA 64 and HPMC 2910 solid dispersions did not contain any isolated polymer-rich phases, hence showed improved homogeneity. Amorphous TPGS 1000 clusters occurred in PVPVA 64 and HPMC 2910 formulations upon addition of at least 10% (w/w) UC 781, showing extremely low glass transition temperatures depending of the thermal history of the samples.  相似文献   

7.
The dissolution rates (mg min-1) of 10 drugs, solid dispersed by fusion in polyethylene glycol 6000 (PEG 6000) have been examined by rotating disc methodology. The dispersions generally displayed release rates which were linearly dependent upon the drug concentration (% drug) at high polymer content. However the range over which this linearity was encountered varied unduly, e.g. 0-2% for phenylbutazone and 0-15% for paracetamol. The slope of this line (mean value: 0.451 mg min-1 % -1) was statistically the same for nine of the drugs studied, the exception being griseofulvin which did not form a true solid dispersion but was a microcrystalline dispersion of the drug within the PEG. During fusion, chain scission of the PEG 6000 occurred in the presence of several drugs. PEG 6000 was incompatible with disulfiram, frusemide, chlorothiazide and chlorpropamide.  相似文献   

8.
Solid dispersion literature, describing the mechanism of dissolution of drug-polyethylene glycol dispersions, still shows some gaps; (A). only few studies include experiments evaluating solid solution formation and the particle size of the drug in the dispersion particles, two factors that can have a profound effect on the dissolution. (B). Solid dispersion preparation involves a recrystallisation process (which is known to be highly sensitive to the recrystallisation conditions) of polyethylene glycol and possibly also of the drug. Therefore, it is of extreme importance that all experiments are performed on dispersion aliquots, which can be believed to be physico-chemical identical. This is not always the case. (C). Polyethylene glycol 6000 (PEG6000) crystallises forming lamellae with chains either fully extended or folded once or twice depending on the crystallisation conditions. Recently, a high resolution differential scanning calorimetry (DSC)-method, capable of evaluating qualitatively and quantitatively the polymorphic behaviour of PEG6000, has been reported. Unraveling the relationship between the polymorphic behavior of PEG6000 in a solid dispersion and the dissolution characteristics of that dispersion, is a real gain to our knowledge of solid dispersions, since this has never been thoroughly investigated. The aim of the present study was to fill up the three above mentioned gaps in solid dispersion literature. Therefore, physical mixtures and solid dispersions were prepared and in order to unravel the relationship between their physico-chemical properties and dissolution characteristics, pure drugs (diazepam, temazepam), polymer (PEG6000), solid dispersions and physical mixtures were characterised by DSC, X-ray powder diffraction (Guinier and Bragg-Brentano method), FT-IR spectroscopy, dissolution and solubility experiments and the particle size of the drug in the dispersion particles was estimated using a newly developed method. Addition of PEG6000 improves the dissolution rate of both drugs. Mechanisms involved are solubilisation and improved wetting of the drug in the polyethylene glycol rich micro-environment formed at the surface of drug crystals after dissolution of the polymer. Formulation of solid dispersions did not further improve the dissolution rate compared with physical mixtures. X-ray spectra show that both drugs are in a highly crystalline state in the solid dispersions, while no significant changes in the lattice spacings of PEG6000 indicate the absence of solid solution formation. IR spectra show the absence of a hydrogen bonding interaction between the benzodiazepines and PEG6000. Furthermore, it was concluded that the reduction of the mean drug particle size by preparing solid dispersions with PEG6000 is limited and that the influence of the polymorphic behavior of PEG6000 (as observed by DSC) on the dissolution was negligible.  相似文献   

9.
The objective of this study was to elucidate the feasibility to improve the solubility and bioavailability of poorly water-soluble itraconazole via solid dispersions by using supercritical fluid (SCF). Solid dispersions of itraconazole with hydrophilic polymer, HPMC 2910, were prepared by the aerosol solvent extraction system (ASES) under different process conditions of temperature/pressure. The particle size of solid dispersions ranged from 100 to 500 nm. The equilibrium solubility increased with decrease (15 to 10 MPa) in pressure and increase (40 to 60 degrees C) in temperature. The solid dispersions prepared at 45 degrees C/15 MPa showed a slight increase in equilibrium solubility (approximately 27-fold increase) when compared to pure itraconazole, while those prepared at 60 degrees C/10 MPa showed approximately 610-fold increase and no endothermic peaks corresponding to pure itraconazole were observed, indicating that itraconazole might be molecularly dispersed in HPMC 2910 in the amorphous form. The amorphous state of itraconazole was confirmed by DSC/XRD data. The pharmacokinetic parameters of the ASES-processed solid dispersions, such as Tmax, Cmax, and AUC(o-24 h) were almost similar to Sporanox capsule which shows high bioavailability. Hence, it was concluded that the ASES process could be a promising technique to reduce particle size and/or prepare amorphous solid dispersion of drugs in order to improve the solubility and bioavailability of poorly water-soluble drugs.  相似文献   

10.
The effects of molecular weight of polyethylene glyeols (PEGs) on the dissolution rates and crystallinity of its solid dispersions with indoniethacin and phenylbutazone have been examined. The dissolution rates of both solid-dispersed drugs decreased as the molecular weight of PEG increased. The indoniethacin dissolution profiles were essentially linear using constant surface area disc methodology and a limiting dissolution rate of about 10.6 mg · min−1 was observed. The phenylbutazone dissolution profiles were. however, generally linear-curvic usually giving lower release rates than the comparative indomethacin weight fractions. A limiting dissolution rate for the linear portions of the profiles was about 1.8 mg · min−1. Infra-red spectra indicated that the differences between the two drugs could partly be explained on the basis of PEG crystallinity. Generally bands in the ranges 1100–1130 and 1200–1400 cm−1 were poorly differentiated in indomethacin dispersions (PEG 1500, PEG 4000 and PEG 6000) but were better differentiated in phenylbutazone dispersions (PEG 4000, PEG 6000 and PEG 20,000). A greater proportion of amorphousness within the PEG moiety was predicted in indomethacin dispersions by the appearance of a new weak band at 1326 cm−1 and by a decrease in intensity of the band at 845 cm−1 at the expense of the peak at 960 cm−1. The evidence was supported by differential scanning calorimetry. The heats of fusion were 44.7, 46.4, 47.2 and 39.5 cal · g−1 for PEG 1500, PEG 4000, PEG 6000 and PEG 20.000 respectively. Heats of fusion for indomethacin dispersions (2, 5 and 10% drug) were generally lower than for the corresponding values for phenylbutazone dispersions-with the exception of PEG 20,000 dispersions. For example, values were obtained of 30.6 and 37.9 cal · g−1 for PEG 1500 dispersions containing 10% indomethacin and phenylbutazone, respectively.  相似文献   

11.
The purpose of this study was to understand the combined effect of two polymers showing drug–polymer interactions on amorphous stabilization and dissolution enhancement of indomethacin (IND) in amorphous ternary solid dispersions. The mechanism responsible for the enhanced stability and dissolution of IND in amorphous ternary systems was studied by exploring the miscibility and intermolecular interactions between IND and polymers through thermal and spectroscopic analysis. Eudragit E100 and PVP K90 at low concentrations (2.5%–40%, w/w) were used to prepare amorphous binary and ternary solid dispersions by solvent evaporation. Stability results showed that amorphous ternary solid dispersions have better stability compared with amorphous binary solid dispersions. The dissolution of IND from the ternary dispersion was substantially higher than the binary dispersions as well as amorphous drug. Melting point depression of physical mixtures reveals that the drug was miscible in both the polymers; however, greater miscibility was observed in ternary physical mixtures. The IR analysis confirmed intermolecular interactions between IND and individual polymers. These interactions were found to be intact in ternary systems. These results suggest that the combination of two polymers showing drug–polymer interaction offers synergistic enhancement in amorphous stability and dissolution in ternary solid dispersions. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3511–3523, 2014  相似文献   

12.
The purpose of this study was to prepare and characterize solid dispersions of the antiviral thiocarboxanilide UC-781 with PEG 6000 and Gelucire 44/14 with the intention of improving its dissolution properties. The solid dispersions were prepared by the fusion method. Evaluation of the properties of the dispersions was performed using dissolution studies, differential scanning calorimetry, Fourier-transform infrared spectroscopy and X-ray powder diffraction. To investigate the possible formation of solid solutions of the drug in the carriers, the lattice spacings [d] of PEG 6000 and Gelucire 44/14 were determined in different concentrations of UC-781. The results obtained showed that the rate of dissolution of UC-781 was considerably improved when formulated in solid dispersions with PEG 6000 and Gelucire 44/14 as compared to pure UC-781. From the phase diagrams of PEG 6000 and Gelucire 44/14 it could be noted that up to approximately 25% w/w of the drug was dissolved in the liquid phase in the case of PEG 6000 and Gelucire 44/14. The data from the X-ray diffraction showed that the drug was still detectable in the solid state below a concentration of 5% w/w in the presence of PEG 6000 and Gelucire 44/14, while no significant changes in the lattice spacings of PEG 6000 or Gelucire 44/14 were observed. Therefore, the possibility of UC-781 to form solid solutions with the carriers under investigation was ruled out. The results from infrared spectroscopy together with those from X-ray diffraction and differential scanning calorimetry showed the absence of well-defined drug–polymer interactions.  相似文献   

13.
目的将难溶性药物阿德福韦酯制备成固体分散体,以增加体外溶出度。方法以聚乙二醇6000(polyethylene glycol 6000,PEG6000)为载体,采用熔融法制备阿德福韦酯固体分散体;配合差示扫描量热(differential scanning calorimetry,DSC)与X-射线衍射(X-ray diffraction,XRD)观察药物在载体中的存在状态;考察相对湿度(relative humidity,RH)75%40℃放置3个月固体分散体对溶出度的变化及载体-药物质量比对溶出的影响。结果阿德福韦酯以无定型状态存在于固体分散体中,相对湿度RH75%40℃放置3个月固体分散体对溶出度改善明显,载体-药物质量比不同,药物的溶出度不同。结论将阿德福韦酯制成固体分散体能显著增加阿德福韦酯的体外溶出度。  相似文献   

14.

Purpose  

The present study aims to determine the drug / polymer miscibility level as a function of the preparation method for an amorphous solid dispersion model system containing itraconazole and eudragit E100. This value was compared to the theoretical crystalline drug solubility in the amorphous polymer and the miscibility of the amorphous drug in the amorphous polymer.  相似文献   

15.
Employing the dispersion technique the influence of mannitol and polyethylene glycol (PEG) 6000 on the in-vitro dissolution of nitrofurantoin was investigated. Dispersions of the drug with PEG 6000 showed faster dissolution rates when compared with dispersions of the drug in mannitol. Tablet formulation of the drug--PEG 6000 dispersion exhibited better drug releasing properties as compared to tablets prepared from the drug's PEG 6000 physical mixture, or the drug's formulation with Avicel PH 101.  相似文献   

16.
Solid dispersions in water-soluble carriers have attracted considerable interest as a means of improving the dissolution rate, and hence possibly bioavailability, of a range of hydrophobic drugs. The aim of the present study was to improve the solubility and dissolution rate of a poorly water-soluble drug, Lovastatin, by a solid dispersion technique. Solid dispersions were prepared by using polyethylene glycol 4000 (PEG 4000) and polyvinylpyrrolidone K30 (PVP K30) in different drug-to-carrier ratios. Dispersions with PEG 4000 were prepared by fusion-cooling and solvent evaporation, whereas dispersions containing PVP K30 were prepared by solvent evaporation technique. These new formulations were characterized in the liquid state by phase solubility studies and in the solid state by differential scanning calorimetry, X-ray powder diffraction, and FT-IR spectroscopy. The aqueous solubility of Lovastatin was favored by the presence of both polymers. The negative values of the Gibbs free energy and enthalpy of transfer explained the spontaneous transfer from pure water to the aqueous polymer environment. Solid-state characterization indicated Lovastatin was present as amorphous material and entrapped in polymer matrix. In contrast to the very slow dissolution rate of pure Lovastatin, the dispersion of the drug in the polymers considerably enhanced the dissolution rate. This can be attributed to improved wettability and dispersibility, as well as decrease of the crystalline and increase of the amorphous fraction of the drug. Solid dispersion prepared with PVP showed the highest improvement in wettability and dissolution rate of Lovastatin. Even physical mixture of Lovastatin prepared with both polymers also showed better dissolution profile than that of pure Lovastatin. Tablets containing solid dispersion prepared with PEG and PVP showed significant improvement in the release profile Lovastatin compared with tablets containing Lovastatin without PEG or PVP.  相似文献   

17.
The present study aimed to improve the bioavailability of biochanin A, a poorly soluble bioflavonoid, via the preparation of solid dispersion (SD) using Solutol HS15 and HPMC 2910. Solubility of biochanin A was enhanced by 8-60 folds as the drug-carrier ratio was increased in SDs. Furthermore, compared to pure biochanin A or physical mixture (PM), SDs significantly improved the dissolution rate and the extent of drug release. Particularly, SDs (Drug:Solutol HS15:HPMC 2910=1:5:5 or 1:10:10) achieved the rapid and complete drug release (approximately 100% within 1h) at pH 6.8. The XRD patterns indicated that SDs might enhance the solubility of biochanin A by changing the drug crystallinity to amorphous state in addition to the solubilizing effect of hydrophilic carriers. The improved dissolution of biochanin A via SD formulation appeared to be well correlated with the enhanced oral exposure of biochanin A in rats. After an oral administration of SD (Drug:Solutol HS15:HPMC 2910=1:10:10), C(max) and AUC of biochanin A were increased by approximately 13 and 5 folds, respectively, implying that SDs could be effective to improve the bioavailability of biochanin A. In conclusion, solid dispersion with Solutol HS15 and HPMC 2910 appeared to be promising to improve the dissolution and oral exposure of biochanin A.  相似文献   

18.
目的采用冷冻干燥法制备缬沙坦(Valsartan)速释固体分散体(SD)来提高其体外溶出度。方法分别以羟丙甲基纤维素(HPMC)、聚乙二醇6000(PEG6000)、聚乙烯吡咯烷酮k30(PVPk30)为载体,十二烷基硫酸钠(SDS)为表面活性剂来制备不同比例的缬沙坦固体分散体,通过测定体外溶出度,来选择最优辅料及比例,结果当以PEG6000载体,SDS为表面活性剂时,且药物:PEG6000:SDS=1:5:1%时药物呈现了很好的水溶性。结论在5min时即可溶出90%以上,很大程度上提高了缬沙坦的体外溶出度。  相似文献   

19.
Cefuroxime axetil (CA) solid dispersions with HPMC 2910/PVP K-30 were prepared using solution enhanced dispersion by supercritical fluids (SEDS) in an effort to increase the dissolution rate of poorly water-soluble drugs. Their physicochemical properties in solid state were characterized by differential scanning calorimeter (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy. No endothermic and characteristic diffraction peaks corresponding to CA were observed for the solid dispersions in DSC and PXRD. FTIR analysis demonstrated the presence of intermolecular hydrogen bonds between CA and HPMC 2910/PVP K-30 in solid dispersions, resulting in the formation of amorphous or non-crystalline CA. Dissolution studies indicated that the dissolution rates were remarkably increased in solid dispersions compared with those in the physical mixture and drug alone. In conclusion, an amorphous or non-crystalline CA solid dispersion prepared using SEDS could be very useful for the formulation of solid dosage forms.  相似文献   

20.
The aim of this study was to investigate the performance of three new solid dispersion formulations of itraconazole in human volunteers in comparison with Sporanox, the marketed form. Solid dispersions made up of itraconazole (40%, w/w) and HPMC 2910, Eudragit E100 or a mixture of Eudragit E100-PVPVA64 were manufactured by hot-stage extrusion and filled in gelatin capsules. The formulations were tested in eight human volunteers in a double blind, single dose, and cross-over study. Concentrations of the drug and its metabolite hydroxyitraconazole in the plasma were determined using HPLC. The in vivo performance was evaluated by comparing the mean area under the plasma concentration-time curves (AUC), the mean maximum plasma concentration (C(max)), and the mean time to reach C(max) (T(max)). The mean bioavailability of itraconazole was comparable after administration of the HPMC solid dispersion, compared to Sporanox, while it was lower after administration of the Eudragit E100 or Eudragit E100-PVPVA64 dispersions. Due to high variability, a significant decrease in AUC and C(max) was only observed for the Eudragit E100-PVPVA formulation. Although the solid dispersions showed different in vitro dissolution behaviour, T(max) values were comparable. The same observations with respect to AUC, C(max) and T(max) could be made for hydroxyitraconazole. The present results indicate that hot-stage extrusion can be considered as a valuable alternative for manufacturing solid dispersions of itraconazole.  相似文献   

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