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1.
目的 采用固体分散技术提高难溶性药物托伐普坦的体外溶出度。方法 选用聚维酮K29/32为载体材料,以溶剂蒸发法制备托伐普坦固体分散体。采用差示扫描量热法(DSC)、X-射线粉末衍射法(XRPD)对所得固体分散体进行鉴定, 并进行溶解度、体外溶出实验。结果 固体分散体的DSC 图谱及X-射线粉末衍射确定了托伐普坦以无定形态分散在载体中, 体外溶解实验表明其溶出较原料药、物理混合物均有明显提高。结论 将托伐普坦与PVP K29/32制成固体分散体,其分散状态发生了改变,溶出性能明显提高。  相似文献   

2.
An amalgamation of solid dispersion and capillarity has been attempted in present study for enhancement of dissolution rate of poorly soluble drugs. Flash evaporation technique was utilized for enhancement of the dissolution rate of piroxicam. One of the major problems with this drug is its very low solubility in biological fluids, which results in poor bioavailability after oral administration. An attempt was made to enhance the dissolution rate of piroxicam by converting it into porous solid dispersion by flash evaporation method using polyvinylpyrrolidone (PVP) 40,000 as a water-soluble carrier. The resulting solid dispersions were characterized by DSC, FTIR, and X-ray diffraction. In vitro dissolution study revealed significant improvement of dissolution profile of piroxicam. The release of drug from porous solid dispersions containing PVP was superior to those of marketed product, conventional nonporous solid dispersion prepared by solvent evaporation method and drug alone. The steep increase in dissolution rate of porous form is attributable to combined effect of solid dispersion and capillarity.  相似文献   

3.
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 of Lovastatin compared with tablets containing Lovastatin without PEG or PVP.  相似文献   

4.
The present research was aimed at the enhancement of the dissolution rate of atorvastatin calcium by the solid dispersion technique using modified locust bean gum. Solid dispersions (SD) using modified locust bean gum were prepared by the modified solvent evaporation method. Other mixtures were also prepared by physical mixing, co-grinding, and the kneading method. The locust bean gum was subjected to heat for modification. The prepared solid dispersions and other mixtures were evaluated for equilibrium solubility studies, content uniformity, FTIR, DSC, XRD, in vitro drug release, and in vivo pharmacodynamic studies. The equilibrium solubility was enhanced in the solid dispersions (in a drug:polymer ratio of 1:6) and other mixtures such as the co-grinding mixture (CGM) and kneading mixture (KM). Maximum dissolution rate was observed in the solid dispersion batch SD3 (i.e. 50% within 15 min) with maximum drug release after 2 h (80%) out of all solid dispersions. The co-grinding mixture also exhibited a significant enhancement in the dissolution rate among the other mixtures. FTIR studies revealed the absence of drug-polymer interaction in the solid dispersions. Minor shifts in the endothermic peaks of the DSC thermograms of SD3 and CGM indicated slight changes in drug crystallinity. XRD studies further confirmed the results of DSC and FTIR. Topological changes were observed in SEM images of SD3 and CGM. In vivo pharmacodynamic studies indicated an improved efficacy of the optimized batch SD3 as compared to the pure drug at a dose of 3 mg/kg/day. Modified locust bean gum can be a promising carrier for solubility enhancement of poorly water-soluble drugs. The lower viscosity and wetting ability of MLBG, reduction in particle size, and decreased crystallinity of the drug are responsible for the dissolution enhancement of atorvastatin. The co-grinding mixture can be a good alternative to solid dispersions prepared by modified solvent evaporation due to its ease of preparation and significant improvement in dissolution characteristics.  相似文献   

5.
This work examines the release of etodolac from various molecular weight fractions of polyethylene glycol (PEG) solid dispersions. Solid dispersions of etodolac were prepared in different molar ratios of drug/carrier by using solvent and melting methods. The release rate of etodolac from the resulting complexes was determined from dissolution studies by use of USP dissolution apparatus 2 (paddle method). The physical state and drug:PEG interaction of solid dispersions and physical mixtures were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR) and differential scanning calorimetry (DSC). The dissolution rate of etodolac is increased in all of the solid dispersion systems compared to that of the pure drug and physical mixtures. The solid dispersion compound prepared in the molar ratio of 1:5 by the solvent method was found to have the fastest dissolution profile. The physical properties did not change after 9 months storage in normal conditions.  相似文献   

6.
Solid dispersions of a poorly water-soluble drug piroxicam in polyvinylpyrrolidone (PVP) were prepared by precipitation with compressed antisolvent (PCA) and spray drying techniques. Physicochemical properties of the products and drug-polymer interactions were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry, etc. Piroxicam was found amorphously dispersed in both solid dispersion systems with the drug to polymer weight ratio of 1:4. Spectra data indicated the formation of hydrogen bonding between the drug and the polymer. Both techniques evaluated in this work resulted in improved dissolution of piroxicam. By comparison, PCA-processed solid dispersions showed distinctly superior performance in that piroxicam dissolved completely within the first 5 min and the dissolution rate was at least 20 times faster than raw drug did within the first 15 min. PCA processing could provide an effective pharmaceutical formulation technology to improve the bioavailability of poorly water-soluble drug.  相似文献   

7.
The aim of present study was to enhance the dissolution rate of poorly water-soluble drug aceclofenac by solid dispersion technique using corn starch, dicalcium phosphate, lactose, and microcrystalline cellulose as carriers. Solid dispersions were prepared by solvent wetting method using 32 full factorial design for each of the carrier. The prepared solid dispersions were evaluated for differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and angle of repose. In vitro dissolution studies were carried out in phosphate buffer (pH 7.5) and 0.1 N HCl (pH 1.2). The results of solid state characterization bring to view that in solid dispersions the crystalline drug gets converted to its amorphous form. FTIR study results indicated the absence of interaction between aceclofenac and carriers. For prepared solid dispersions, angle of repose was found to be in the range of 26.19° to 35.29°, which indicates good flowability. Enhanced drug dissolution was obtained with carrier in order lactose > corn starch > microcrystalline cellulose > dicalcium phosphate. Hence, these carriers could be used to enhance the dissolution rate of poorly water-soluble drug.  相似文献   

8.
目的提高难溶性药物酮洛芬体外溶出速度。方法以聚乙烯吡咯烷酮(PVPK30)为载体,制备药物与载体不同比例的固体分散物及物理混合物,采用X射线衍射和红外吸收方法,比较二者及药物的结晶形态,并进行体外药物溶出度的测定。结果固体分散物体外溶出速率明显高于物理混合物及酮洛芬原料的体外溶出速度,且随载体比例增加而增大。固体分散物的X射线衍射及红外吸收图谱确定了酮洛芬以无定形态分散在载体中,放置6个月后,固体分散物X射线衍射图谱没有明显变化。结论药物与载体以合适比例制备的固体分散物可以明显提高药物体外溶出速度。  相似文献   

9.
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   

10.
Aim of the present study was to improve the solubility and dissolution rate of poorly water soluble, BCS class-II drug Ketoprofen (KETO) by solid-dispersion approach. Solid dispersions were prepared by using polyvinylpyrrolidone K30 (PVP K30) and d-mannitol in different drugs to carrier ratios. Dispersions with PVP K30 were prepared by kneading and solvent evaporation techniques, whereas solid dispersions containing d-mannitol were prepared by kneading and melting techniques. These formulations were characterized in the liquid state by phase-solubility studies and in the solid state by Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The aqueous solubility of KETO was favored by the presence of both carriers. The negative values of Gibbs free energy illustrate the spontaneous transfer from pure water to the aqueous polymer environment. Solid state characterization indicated KETO was present as fine particles in d-mannitol solid dispersions and entrapped in carrier matrix of PVP K30 solid dispersions. In contrast to the very slow dissolution rate of pure KETO, dispersions of drug in carriers considerably improved the dissolution rate. This can be attributed to increased wettability and dispersibility, as well as decreased crystallinity and increase in amorphous fraction of drug. Solid dispersions prepared with PVP K30 showed the highest improvement in dissolution rate of KETO. Even physical mixtures of KETO prepared with both carriers also showed better dissolution profiles than those of pure KETO.  相似文献   

11.
Properties of solid dispersions of piroxicam in polyvinylpyrrolidone.   总被引:5,自引:0,他引:5  
Solid dispersions of piroxicam were prepared with polyvinylpyrrolidone (PVP) K-17 PF and PVP K-90 by solvent method. The physical state and drug:PVP interaction of solid dispersions and physical mixtures were characterized by X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). FTIR analysis demonstrated the presence of intermolecular hydrogen bonding between piroxicam and PVP in solid dispersions. These interactions reflected the changes in crystalline structures of piroxicam. The amorphousness within the PVP moeity might be predicted in piroxicam dispersions by the disappearance of N-H or O-H peak of piroxicam. Dissolution studies indicated a significant increase in dissolution of piroxicam when dispersed in PVP. The better results were obtained with the lower molecular weight PVP K-17 than with higher molecular weight PVP K-90. The non-amorphous solid dispersions in PVP K-17 showed almost equally fast dissolution rates to amorphous dispersions in PVP K-90. The mechanism of dissolution of solid dispersion in PVP K-90 is predominantly diffusion-controlled due to the very high viscosity of PVP K-90. Dissolution was maximum with the amorphous solid dispersions containing drug:PVP K-17 1:5 and 1:6 which showed a 40-fold increase in dissolution in 5 min as compared with pure drug. Copyright  相似文献   

12.
Liqui-solid technique and solid dispersion formation are two novel approaches for enhancement of dissolution rate of BCS class II drugs. Liqui-solid compact converts a liquid drug or drug solution into a free flowing powder with enhanced dissolution rate. In case of solid dispersion drug is molecularly dispersed in a hydrophilic polymer in solid state. In the present study, Liqui-solid and solid dispersion techniques were applied to enhance the dissolution of the Hydrochlorothiazide. Three formulations of Hydrochlorothiazide were prepared by liqui-solid technique using micro crystalline cellulose as carrier material and colloidal silicon dioxide as coating material. Water, poly ethylene glycol-400 and Tween-60 were used as solvent system. Solid dispersions of Hydrochlorothiazide were prepared by solvent fusion method using PEG-4000 as carrier polymer. Tablets were subjected to evaluation of various physical and chemical characteristics. Dissolution profiles of tablets prepared by the novel techniques were compared with marketed conventional tablets. Model independent techniques including similarity factor, dissimilarity factor and dissolution efficiency were applied for comparison of dissolution profiles. The results obtained indicated that liqui-solid compact formulations were more effective in enhancing the dissolution rate compared with solid dispersion technique. The liqui-solid compacts improved the dissolution rate up to 95% while the solid dispersion increased it to 88%.  相似文献   

13.
Solid dispersions of mefanamic acid with a water-soluble polymer polyvinyl pyrrolidine and a super disintegrant, primojel were prepared by common solvent and solvent evaporation methods employing methanol as the solvent. The dissolution rate and dissolution efficiency of the prepared solid dispersions were evaluated in comparison to the corresponding pure drug. Solid dispersions of mefenamic acid showed a marked enhancement in dissolution rate and dissolution efficiency. At 1:4 ratio of mefenamic acid-primojel a 2.61 fold increase in the dissolution rate of mefenamic acid was observed with solid dispersion. The solid dispersions in combined carriers gave much higher rates of dissolution than super disintegrants alone. Mefanamic acid-primojel-polyvinyl pyrrolidine (1:3.2:0.8) solid dispersion gave a 4.11 fold increase in the dissolution rate of mefenamic acid. Super disintegrants alone or in combination with polyvinyl pyrrolidine could be used to enhance the dissolution rate of mefenamic acid.  相似文献   

14.
To improve the solubility of poorly water-soluble drugs, we studied physical characteristics of griseofulvin (GF) solid dispersions with saccharides as the dispersion carrier using a roll mixing method. In all carriers tested, roll mixtures of GF and saccharides gradually became amorphous, and the solubility of GF increased. The solubility of GF was higher in the mixtures with higher molecular weight carriers such as corn starch and processed starch. The dissolution of GF was markedly improved by the GF-Britishgum roll mixture. The initial dissolution rate of these mixtures was 170-fold higher than GF alone. The surface tension of carrier aqueous solutions was low in the processed starch with branched sugar chains. The initial dissolution rate of GF in physical mixtures was correlated with the surface tension of carrier aqueous solutions. The stability of the amorphous state of GF at a high humidity was maintained in the mixtures with carriers with a high molecular weight. These results indicated that the solubility of GF was markedly improved in the roll mixtures. It was suggested that the saccharides with a high molecular weight are useful carriers for solid dispersions.  相似文献   

15.
目的:采用固体分散体技术考察不同载体材料对布渣叶总黄酮提取物溶出度的影响.方法:选择不同种类的聚乙二醇、泊洛沙姆、聚乙烯吡咯烷酮为载体材料,与布渣叶总黄酮提取物按质量比1:4混合均匀,分别用熔融法和溶剂法制备固体分散体,以固体分散体中总黄酮、牡荆苷、异牡荆苷、水仙苷的90 min累积溶出度作为评价指标,比较不同载体制备的固体分散体的释药速率,并采用X射线衍射和红外光谱分析对其物相特征进行研究.结果:与布渣叶总黄酮提取物和物理混合物相比,以PEG和泊洛沙姆所制备的布渣叶提取物固体分散体中总黄酮、牡荆苷、异牡荆苷和水仙苷的体外溶出度与溶出速率均明显增加.其中以泊洛沙姆407为载体材料所制备的固体分散体中总黄酮体外溶出度最佳,90 min累积溶出度达到84%;以PEG 6000为载体材料所制备的固体分散体中牡荆苷、异牡荆苷、水仙苷体外溶出度最佳,90 min累积溶出度均达96%以上.结论:采用固体分散体技术,选择PEG 6000或泊洛沙姆407为载体制备布渣叶总黄酮提取物固体分散体,对提取物中脂溶性成分的溶出有明显改善作用.  相似文献   

16.
The oral bioavailability of nalidixic acid (NA) is low due to its poor solubility and slow dissolution. Solid dispersions of NA containing varying concentrations of polyvinylpyrrolidone (PVP), beta-cyclodextrin (BCD) and sodium starch glycolate (SSG) were prepared by solvent evaporation technique in an attempt to improve dissolution rate of NA. Physical characterization of NA, physical mixtures (PM) and solid dispersions were investigated by a variety of analytical methods including scanning electron microscopy (SEM), infrared (IR) spectroscopy and powder X-ray diffraction (XRD). SEM was useful in the verification of possible nalidixic acid inclusion in the dispersion system by studying its surface and shape characteristics of different samples. IR analysis demonstrated no strong interaction between the drug and the carrier exists in the solid dispersions. The degree of crystallinity of nalidixic acid decreased and also differed with the dispersion systems of different carriers. Disolution studies indicated that the dissolution rate and percent dissolution efficiency (DE) were significantly increased in the solid dispersions compared with drug alone. The relative potency of the carriers to enhance the dissolution rate of nalidixic acid was in the order: BCD > PVP > SSG. The dissolution rate of the drug in the solid dispersions was faster when the ration of the drug to carrier was smaller. F-test suggests that first order model may be used for explaining the kinetics of drug release from all the solid dispersion systems.  相似文献   

17.
Solid dispersions and physical mixtures made up of the poorly water-soluble drug UC 781, a polymer and a surfactant were prepared to contribute to the understanding of the relationship between physicochemical characteristics and dissolution behaviour. In addition, to facilitate downstream processing while still favouring drug dissolution to a maximum extent, formulation conditions were investigated to obtain a free flowing powder which contains a maximum amount of surfactant. Poloxamer 407, a polyethylene-polypropylene glycol block copolymer, was selected as a suitable polymer based on UC 781 supersaturation results. d-Alpha-tocopheryl polyethyleneglycol succinate 1000 (TPGS 1000) was preferred as a surfactant since it increased UC 781 dissolution when formulated in a self-micro emulsifying drug delivery system (SMEDDS), as compared to TPGS 400, TPGS 4000 and TPGS 6000. Based on flow properties, a TPGS 1000/Poloxamer 407 ratio of 80/20 was used to prepare solid dispersions by spray drying. Pure drugs, physical mixtures and solid dispersions were characterized by differential scanning calorimetry and X-ray powder diffraction. Eutectic phase behaviour was obtained in which the relative distribution of the polyethylene glycol folding was dependent on UC 781 concentration. Drug release was markedly increased when formulated as a solid dispersion with Poloxamer 407 and TPGS 1000. Formulation of solid dispersions did however not further improve the drug dissolution rate compared to that of physical mixtures. Nonetheless, variability of dissolution results was considerably reduced upon solid dispersion formulation.  相似文献   

18.
The aim of the study was in vitro evaluation of piroxicam solid dispersions containing hydroxypropyl methylcellulose acetate succinate (HPMCAS-LF, -HF) as a carrier. Binary (piroxicam–HPMCAS) and ternary (piroxicam–HPMCAS–Carbopol 940) solid dispersions were prepared by spray-drying method. The morphological characteristics were investigated by scanning electron microscopy. X-ray diffraction and differential scanning calorimetry were employed to study physical and chemical properties. In vitro release was studied using a flow-through cell technique. Studies of dissolution rate of piroxicam from solid dispersions were carried out in comparison with corresponding physical mixtures and drug alone. The dissolution profiles depend on the presence of Carbopol 940 in solid dispersions.  相似文献   

19.
Carbamazepine (CBZ) shows a poor dissolution, therefore, it is important to enhance its dissolution in GI tract to improve its bioavailability. In the present study, a new hydrophilic carrier, d-gluconolactone (GNL), was extruded with CBZ at various molar ratios to produce granules by using hot melt extrusion (HME) processing. The granular extrudates were characterised by X-ray powder diffraction, differential scanning calorimetry and hot stage microscopy to determine the solid state of CBZ. It was found that bulk CBZ (Form-III) transformed to the polymorphic Form-I during the HME processing. GNL was proved to be an efficient carrier for CBZ to enhance the dissolution rate. The increase in the dissolution rate was observed for both physical mixtures and the extrudates of CBZ-GNL. However, the extrudates showed faster dissolution rates compared to physical mixtures in an ascending order of 2:1?<?1:1?<?1.5:1 (CBZ:GNL). The increase in the dissolution rates was attributed to the transformation of CBZ III to Form-I and also to the increased drug wettability/solubilisation in the presence of the carrier.  相似文献   

20.
This investigation describes a novel approach to prepare solid dispersions of tanshinone IIA using a laboratory-scale planetary ball mill. Poloxamer 188 was employed as the surfactant carrier to improve the solubility and dissolution of the poorly soluble drug, tanshinone IIA. Solubility and dissolution were evaluated compared to the corresponding physical mixtures and pure drug. Furthermore, the physicochemical properties of the solid dispersions were investigated using scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy and ultraviolet spectrophotometry. The solid dispersion significantly enhanced drug solubility and dissolution compared with pure drug and the physical mixtures. Scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry and Fourier transform infrared spectroscopy analyses of tanshinone IIA/poloxamer 188 system confirmed that there were intermolecular interactions between tanshinone IIA and poloxamer 188 and no conversion to crystalline material. Tanshinone IIA existed in a microcrystalline form in the system. These results suggested that improvement of the dissolution rate could be correlated to the formation of a eutectic mixture between the drug and the carrier. After 60 days the solid dispersion samples were chemically and physically stable. The present studies indicated that the planetary ball mill technique could be considered as a novel and efficient method to prepare solid dispersion formulations.  相似文献   

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