固体分散技术提高黄芩提取物溶出度的研究

目的：通过制备固体分散体，提高黄芩提取物的溶出度。方法：采用熔融法和溶剂法，制备聚乙二醇4000（PEG4000），聚乙二醇6000（PEG6000），聚乙烯吡咯烷酮K30（PVPK30）3种载体材料及不同比例条件下的固体分散体。通过比较原药材、固体分散体、机械混合物的溶出性能，从而确定制备的最佳方法和最佳比例。结果：不同载体不同比例的固体分散体均能提高药物的溶出度，且载体比例越大，药物的溶出越快，3种载体的增溶效果依次为PVPK30〉PEG4000〉PEG6000。结论：以PVP为载体，采用溶剂法所制备的药物/载体比例为1：6的固体分散体能显著提高黄芩提取物的溶出速率。     

氨苯砜固体分散体的制备与溶出度测定

目的制备氨苯砜固体分散体，增大氨苯砜溶出度。 方法以聚乙二醇6000(PEG 6000)为载体，采用熔融法，按照不同比例制备固体分散体，并进行体外溶出度研究。结果体外溶出实验表明分散体的溶出速率明显快于原料药及物理混合物，且载体比例越大，药物溶出越快。结论将氨苯砜制备成固体分散体，可以增大其溶出度，有利于提高其剂型的生物利用度。     

尼莫地平固体分散体在速释制剂中的溶出性质

为了提高难溶性药物尼莫地平的溶出度,并在此基础上研制出其速释制剂,本研究选用PVP（k30)为载体制备了尼莫地平的固体分散体及机械混合物,比较了二者体外药物溶出度及药物的结晶形态,并考查了共沉淀物的稳定性,进而进行了尼莫地平速释片剂处方的筛选,并按最优处方制备了胶囊剂,比较了自制速释胶囊剂与市售片剂的释药情况,体外实验结果表明,固体分散体对尼莫地平溶出度的提高大大优于机械混合物,5分钟的释药量,前者为89％, 而后者仅为45％,X－射线衍射实验表明,尼莫地平在以PVP为载体的固体分散体中是以非晶体形式存在,并且在室温并密封于玻璃瓶中放置一年后仍无结晶出现,本研究制备的片剂和胶囊剂都具有速释性质,而以胶囊剂为优,说明压片压力可能影响溶出,速胶胶囊的释药速率大大高于市售普通片剂。     

桂利嗪-聚乙二醇固体分散体的制备及体外溶出实验

目的：应用固体分散技术提高难溶性药物桂利嗪的溶解度和体外溶出速率。方法：采用溶剂-熔融法制备桂利嗪-聚乙二醇（PEG6000）固体分散体，并进行体外溶出度研究。结果：桂利嗪-聚乙二醇固体分散体的水中溶解度和体外溶出度高于原药，且载体加入量越大，溶出越快；比例相同的固体分散体的溶出度明显高于其物理混合物。结论：本实验所制备的桂利嗪-聚乙二醇固体分散体能加速体外溶出和增大溶解度。     

尼莫地平固体分散体在速释制剂中的溶出性质(英)

为了提高难溶性药物尼莫地平的溶出度,并在此基础上研制出其速释制剂,本研究选用PVP（k30）为载体制备了尼莫地平的固体分散体及机械混合物,比较了二者体外药物溶出度及药物的结晶形态,并考查了共沉淀物的稳定性。进而进行了尼莫地平速释片剂处方的筛选,并按最优处方制备了胶囊剂。比较了自制速释胶囊剂与市售片剂的释药情况。体外实验结果表明,固体分散体对尼莫地平溶出度的提高大大优于机械混合物,5分钟的释药量,前者为89％,而后者仅为45％。X-射线衍射实验表明,尼莫地平在以PVP为载体的固体分散体中是以非晶体形式存在,并且在室温并密封于玻璃瓶中放置一年后仍无结晶出现。本研究制备的片剂和胶囊剂都具有速释性质,而以胶囊剂为优,说明压片压力可能影响溶出。速释胶囊的释药速率大大高于市售普通片剂。     

索法酮固体分散体的制备及体外溶出特性

目的:制备索法酮固体分散体并考查其体外溶出特性.方法:以PEG 2000、PEG 4000和PEG 6000为载体,采用熔融法制备固体分散体,与物理混合物比较体外溶出度.结果:PEG 4000和PEG 6000制得的固体分散体的体外溶出度高于PEG 2000,均高于物理混合物.载体比例越大,体外溶出越快.结论:以PEG为载体,采用熔融法可制得体外溶出较快的索法酮固体分散体.     

瑞格列奈固体分散体的制备及体外溶出

目的制备瑞格列奈的固体分散体,提高瑞格列奈的体外溶出度。方法以聚乙二醇6000(polyethylene glycol 6000,PEG6000)作为载体,采用溶剂-熔融法制备不同处方的瑞格列奈固体分散体,进行溶出度考查。采用红外光谱、差示扫描量热(differential scanning calorimetry,DSC)与X-射线衍射(X-ray diffraction,XRD)对瑞格列奈固体分散体进行物相分析。结果与瑞格列奈原料和物理混合物相比,固体分散体可显著提高瑞格列奈的体外溶出度,物相鉴定表明,瑞格列奈大部分以无定形状态分散于PEG6000中,提高了药物的体外溶出度。结论制备瑞格列奈的PEG6000固体分散体能显著提高药物的体外溶出度,可满足速释制剂的要求。     

依托泊苷固体分散体的制备及体外研究

目的 制备依托泊苷固体分散体，改善依托泊苷的溶出度。方法 应用聚乙烯吡咯烷酮（PVPK30）和聚乙二醇（PEG6000）为载体，以溶剂法制备固体分散体。采用正交实验设计考察制备固体分散体的最佳工艺条件，并对所得样品进行体外溶出度研究，以X线衍射、DSC-量热分析进行物相鉴定。结果 依托泊苷在载体PVPK30和PEG6000中结晶消失。药物的溶出速度随载体比例增加而增加。结论 采用PVPK30和PEG6000所制依托泊苷固体分散体能显著提高药物的体外溶出度，药物以无定形状态或分子态存在于载体中。     

阿司匹林固体分散物的研究

目的:制备阿司匹林固体分散物;选择不影响阿司匹林稳定性的PEG 载体及其合适比例;测定阿司匹林固体分散物的体外溶出速率;分析其结构状态。方法:固体分散物的制备采用熔融法;体外溶出采用浆法;固体分散物的结构分析采用X 射线衍射法。结果:PEG 所占比例越大,熔融法制备固体分散物时,阿司匹林的水解程度越低,且PEG20000 优于PEG6000 ;阿司匹林-PEG20000(1∶9) 固体分散物的标示百分含量为104 .68 % ,水杨酸检查合格;与原料药和物理混合物相比,其溶出度显著增加(P< 0 .01) ;该固体分散物中大部分阿司匹林以分子状态分散,只有极少部分以微晶状态分散。结论:以PEG20000 为载体,按阿司匹林 PEG= 1∶9 的比例制备阿司匹林固体分散物是理想的,该分散物体外溶出迅速,可用于制备小规格的片剂,在不影响疗效的前提下,通过减小剂量来降低阿司匹林对胃肠道的刺激性     

蛇床子素—聚乙二醇固体分散体的特性及有关分析方法研究

目的建立固体分散体中蛇床子素的分析方法、考察其有关特性。方法应用聚乙二醇6000(PEG6000)为载体,采用熔融法制备了蛇床子素(Osthole,OSL)的固体分散体,测定了OSL原料药、固体分散物以及机械混合物的体外溶出度,通过扫描电镜观察、红外光谱及紫外光谱分析对固体分散物进行了研究。结果及结论OSL固体分散物的溶出度与OSL原料药和机械混合物相比有明显提高;OSL以超细态分散于载体中,OSL分子和载体分子之间未发生化学变化。     

格列喹酮固体分散体的制备及溶出度测定

目的:制备格列喹酮固体分散体并考察其体外溶出性。方法:以聚乙烯吡咯烷酮K30(PVP)、聚乙二醇6000(PEG)为载体,溶剂熔融法和溶剂法制备格列喹酮固体分散体,并与原料药比较体外溶出度。结果:载体比例越大,药物溶出愈快。载体为PVP所制固体分散体的体外溶出行为总体优于载体为PEG者。格列喹酮-PVP固体分散体(1∶7)10min内体外溶出度达到70%以上,优于格列喹酮原料药。结论:成功制备了格列喹酮固体分散体。     

热熔挤出技术制备吡罗昔康固体分散体

目的采用热熔挤出技术制备难溶性药物吡罗昔康固体分散体,来提高其溶出速率。方法以共聚维酮(PVP-VA64)为亲水性载体材料,聚乙二醇6000为增塑剂,采用热熔挤出技术制备吡罗昔康固体分散体。通过比较差示扫描量热图谱和累积溶出曲线,来表征和评价所制备的固体分散体。结果所制备的固体分散体溶出速率较物理混合物均显著提高。结论热熔挤出技术适用于制备吡罗昔康固体分散体,药物是以无定型分散在载体中,溶出度得到显著提高。     

联苯双酯制剂的物理分散状态及体外释放度

用X-射线衍射法,考察不同载体制备的固体分散体系中联笨双酯的物理分散状态,聚乙二醇6000(PEG 6000)固体分散系为有限互溶固体溶液,聚乙烯吡咯烷酮(PVP)共沉淀物为无定形粉末,脲共熔物为简单低共熔混合物,热分析研究亦证实PEG 6000固体分散物较其相应比例的物理混合物及片剂有更高的分散度。比较两种联苯双酯片剂与滴丸的体外释放度,两种片剂的释放度参数td值分别为37和178min,滴丸未包衣者为11min,包衣者为26.in。由此可知物理分散状态是影响释放速度的主要因素。     

联苯双酯制剂的物理分散状态及体外释放度

用X-射线衍射法,考察不同载体制备的固体分散体系中联笨双酯的物理分散状态,聚乙二醇6000(PEG 6000)固体分散系为有限互溶固体溶液,聚乙烯吡咯烷酮(PVP)共沉淀物为无定形粉末,脲共熔物为简单低共熔混合物,热分析研究亦证实PEG 6000固体分散物较其相应比例的物理混合物及片剂有更高的分散度。比较两种联苯双酯片剂与滴丸的体外释放度,两种片剂的释放度参数td值分别为37和178min,滴丸未包衣者为11min,包衣者为26.in。由此可知物理分散状态是影响释放速度的主要因素。     

甲苯磺丁脲固体分散物的X线衍射研究

用X线衍射(XRD)对甲苯磺了脲(D860)与脲、聚乙烯吡咯烷酮(PVP)和聚乙烯二醇6000(PEG 6000)的固体分散物进行较详细的研究,并与它们的溶出速率进行关联。D860—PVP分散物为无定形态,溶出速率大。用熔融法制备的固体分散物中,D860在D860—脲,D860—PEG中为部分互溶,部分呈微晶析出,为过饱和状态,活性强,溶出速率快。而用溶剂法制备的D860—PEG近似物理混合状态,大部分以微晶形态分散,溶出速率较慢。陈化试验表明D860分散物在贮存期间无晶体结构变异,溶出速率的下降估计是由于药剂活性改变所致。     

Mechanism of increased dissolution of diazepam and temazepam from polyethylene glycol 6000 solid dispersions

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.     

Physicochemical characterization and dissolution study of solid dispersions of Lovastatin with polyethylene glycol 4000 and polyvinylpyrrolidone K30

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.     

Improvement of the dissolution kinetics of SR 33557 by means of solid dispersions containing PEG 6000

Solid dispersions of SR 33557 in preparations containing from 30 to 80% w/w polyethylene glycol 6000 (PEG 6000) were prepared by the fusion method. The solubility of the drug substance either alone or in solid dispersions was determined in pH 1.2 and 4.5 media (extraction fluid NFXII, without enzyme). A large increase in the solubility was noted from the 80% w/w PEG preparation. A wettability study performed by measuring the contact angle on tablets of either drug substance or PEG 6000, or solid dispersions, revealed a minimal contact angle for the 80% w/w PEG 6000 solid dispersion (eutectic composition of SR 33557/PEG 6000 phase diagram). Dissolution kinetic analysis performed at pH 1.2 on all solid dispersions, on the physical mixtures containing 70 and 80% w/w PEG 6000, and on SR 33557 alone, showed a maximum release rate (100%) for the solid dispersions containing 70 and 80% w/w PEG 6000. The dissolution rate of the physical mixtures was faster than that of the drug substance alone but remained, however, lower than that of the solid dispersions, at the same composition. It was also observed that the dissolution rate, at pH 1.2 and 4.5, of the 70% w/w PEG 6000 solid dispersion was practically pH independent, which was not the case for the drug substance alone. The latter solid dispersion showed a slowing down of the dissolution kinetics after 3 months storage at 50°C whereas no change in the dissolution rate was observed following storage for 12 months at 25°C.     

Physicochemical Characterization and Dissolution Study of Solid Dispersions of Lovastatin with Polyethylene Glycol 4000 and Polyvinylpyrrolidone K30

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.