齐酞酸钠固体分散物的制备和体外溶出度研究

目的采用固体分散技术提高齐酞酸钠口服制剂的溶出速度和稳定性。方法以肠溶性材料聚丙烯酸树脂Ⅲ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-射线衍射方法、差热分析和红外光谱分析鉴别分散状态，并测定体外溶出速度。结果齐酞酸钠以无定形态分散在载体中，主要在碱性溶液中溶出，形成肠溶性固体分散物，溶出速率高于物理混合物。结论齐酞酸钠与载体适当比例的肠溶性固体分散物可明显提高体外溶出速率，并可防止药物的水解。     

马来酸罗格列酮固体分散体及其溶出速率

目的提高难溶性药物马来酸罗格列酮的体外溶出速率 ,满足脉冲制剂的设计要求。方法选用PVPK3 0为载体 ,用溶剂法制备了马来酸罗格列酮固体分散体 ,比较考察了原料药及其物理混合物和固体分散体的溶出差别 ,并通过红外光谱及X 射线粉末衍射对固体分散体进行了鉴定。结果体外溶出结果表明固体分散体能显著增加药物在水中及人工肠液中的溶出速率 ;红外光谱分析结果表明药物与载体之间没有发生化学反应 ;X 射线粉末衍射图谱表明药物以无定形状态分散于载体PVPK3 0中。结论固体分散体体外溶出速率的提高可以满足脉冲制剂的设计要求。     

西尼地平固体分散物的制备及体外溶出度的测定

目的 通过制备固体分散物提高西尼地平体外溶出速率。方法 以聚乙烯吡咯烷酮（PVP-k30）为载体，采用溶剂—熔融法和物理法制备固体分散物。采用差示扫描量热法（DSC）确定西尼地平以无定型状态分散在载体中，并进行了药物体外溶出度的测定。结果 固体分散物的体外溶出速率明显高于物理混合物的体外溶出速率。DSC图谱检测能充分说明采用溶剂—溶融法能够形成较好的固体分散物，药物与载体的晶体吸收峰已经消失。结论 形成稳定固体分散物后制成制剂，体外溶出度显提高。     

伊曲康唑固体分散体制备及体外溶出实验

目的:运用固体分散体技术提高难溶性药物伊曲康唑的溶解度及体外溶出速率.方法:选用聚乙烯吡咯烷酮(PVPK30)为载体,采用喷雾干燥法制备伊曲康唑固体分散体,通过差热分析及X射线衍射对固体分散体进行鉴定,比较考察伊曲康唑及其物理混合物和固体分散体的溶出特性.结果:差热分析、X射线衍射图谱表明药物以无定形状态分散于载体中;体外溶出结果表明固体分散体能显著增加药物在水及人工胃液中的溶出度(45 min时1:4固体分散体体外溶出度为伊曲康唑的11.5倍.1:4固体分散体在0.1 mo1·L-1盐酸中溶解度是伊曲康唑的67倍).结论:伊曲康唑固体分散体能明显提高伊曲康唑的溶解度及体外溶出速率.     

环孢素-泊洛沙姆188固体分散体的体外评价

目的以泊洛沙姆188（F68）为载体制备环孢素（CsA）固体分散体并考察其体外溶出。方法以溶剂一熔融法制备固体分散体，以差示扫描量热法（DSC）和X．射线衍射法鉴定CsA在体系中的存在状态，以FTIR表征药物与载体的相互作用，以摇瓶法测定CsA的溶解度，按《中国药典》溶出度第三法测定CsA从物理混合物和固体分散体中的溶出。结果X-射线衍射图谱显示CsA结晶衍射峰消失，提示药物以无定形或分子状态存在于固体分散体中。FTIR结果表明药物与载体间无相互作用。药物溶解度和溶出度均随着F68比例的增加而增大，固体分散体和物理混合物60min的累积溶出百分率分别为99．32％和75．41％，两者具显著性差异（P〈0．01）。结论F68能提高CsA的溶解度和溶出度，可用来制备CsA的固体剂型。     

托伐普坦固体分散体的制备及体外溶出特性考察

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K_29/32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 K_29/32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。     

泊洛沙姆固体分散体对穿心莲内酯溶出特性的影响

目的:考察泊洛沙姆固体分散体对难溶性药物穿心莲内酯体外溶出特性的影响。方法:以泊洛沙姆为载体材料,采用熔融法制备不同比例的穿心莲内酯-泊洛沙姆固体分散体,并考察其体外溶出特性。通过红外光谱和X射线衍射图谱研究药物在固体分散体的存在状态。结果:与穿心莲内酯空白药物相比,穿心莲内酯固体分散体在蒸馏水、pH1.2盐酸溶液与pH6.8磷酸盐缓冲液中溶出速率明显提高,载药固体分散体15min时累积释药量是穿心莲内酯空白药物的3.6倍;穿心莲内酯以微晶态高度分散于载体材料中。结论:以泊洛沙姆188为载体制备穿心莲内酯固体分散体,能有效提高难溶性药物的溶出速率。     

阿司匹林固体分散体及其胶囊的制备与体外溶出度研究

目的:制备阿司匹林固体分散体及其胶囊,并研究其体外溶出度。方法:以聚乙烯吡咯烷酮为载体,采用喷雾干燥法制备阿司匹林固体分散体,比较阿司匹林原料药、阿司匹林与载体不同比例的物理混合物和固体分散体的溶出度;采用X-射线衍射和扫描电镜考察药物在载体中的分散状态,测定比表面积;考察阿司匹林固体分散体胶囊的体外溶出度。结果:与阿司匹林原料药、阿司匹林物理混合物比较,阿司匹林固体分散体中药物的溶出度均有提高,且载体比例越大,药物溶出越快,但药物-载体比例达1∶6以上时,溶出度增加不再明显;阿司匹林以无定型或分子形式高度分散在载体中;药物-载体在l∶6时,阿司匹林固体分散体比阿司匹林原料药的比表面积增大3.2倍;制成固体分散体胶囊后,30 min时药物累积溶出度达99.8%。结论:该固体分散体制备工艺可行,制备的胶囊质量可控。     

(噁)丙嗪固体分散体的制备

目的:制备噁丙嗪固体分散体.方法:以聚乙二醇(PEG 6000)为载体,采用熔融法制备噁丙嗪固体分散体,桨法测定体外溶出度,X-射线衍射法分析结构状态.结果:噁丙嗪-PEG 6000固体分散体是一种简单低共熔混合物,噁丙嗪以超细结晶状态分散在PEG载体中.1:5,1:7,1:9,1:11比例固体分散体的标示含量均在98%～106%范围.与原料药及物理混合物相比,固体分散体的溶出速度和程度均显著增加(P＜0.01);且随着载体比例的逐渐增大,固体分散体的药物溶出加快.结论:以PEG 6000为载体制备的噁丙嗪固体分散体体外溶出迅速,可用于制备速效、高效的噁丙嗪口服制剂.     

瑞戈非尼固体分散体的制备及体外溶出度考察

目的采用固体分散技术提高难溶性药物瑞戈非尼的体外溶出度。方法选用聚维酮K30为载体,以溶剂法制备不同比例的瑞戈非尼固体分散体;采用紫外分光光度法测定其溶出度;采用X-射线粉末衍射法分析药物在固体分散体中的存在状态。结果瑞戈非尼固体分散体的溶出度较原料药、物理混合物均有显著提高,且载体比例越大,固体分散体溶出度越大;瑞戈非尼以无定形态分散在载体中。结论采用固体分散技术可有效提高瑞戈非尼的体外溶出度。     

Dissolution behaviour of nalidixic acid solid dispersions using water soluble dispersion carriers

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.     

Enhanced release of solid dispersions of etodolac in polyethylene glycol

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.     

Preparation of a solid dispersion of felodipine using a solvent wetting method.

A straightforward solvent wetting method was used to prepare felodipine solid dispersions in the presence of various carriers. Dichloromethane is not needed when HPMC solid dispersions were produced using the solvent wetting method. The amount of ethanol used to prepare solid dispersions did not have a significant effect on the dissolution rate of felodipine. The results of X-ray diffraction and thermal analysis indicated that the drug was in the amorphous state when PVP, HPMC, and poloxamer were used as carriers. The dissolution rates of felodipine in PVP, HPMC, or poloxamer solid dispersions were much faster than those for the corresponding physical mixtures. However, dissolution profiles were found to depend on the carrier used; the dissolution rate of felodipine increased slowly for solid dispersions prepared using HPMC, whereas rapid initial dissolution rates were observed for solid dispersions prepared using PVP or poloxamer. Increases in dissolution rates were partly dependent on the ratios of felodipine to carrier. No significant changes in crystal form were observed by X-ray diffraction or thermal analysis, and no significant changes in dissolution rate were observed when sorbitol and mannitol were used as carriers.     

Properties of solid dispersions of piroxicam in polyvinylpyrrolidone.

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     

Physicochemical characterization and in vitro dissolution studies of solid dispersions of ketoprofen with PVP K30 and d-mannitol

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.     

Studies on Flash Evaporation for Preparation of Porous Solid Dispersions Using Piroxicam as a Model Drug

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.     

Preparation of evodiamine solid dispersions and its pharmacokinetics

In order to increase the dissolution rate and bioavailability, solid dispersions of evodiamine in PVP K(30) with different enriched samples of evodiamine to PVP K(30) ratios were prepared by solvent method. Our studies showed that the dissolution rate of evodiamine was significantly higher in the solid dispersion system in comparison with that in enriched samples of evodiamine or physical mixtures. The increase of the dissolution rate was evidently related to the ratio of evodiamine to PVP K(30). The solid dispersion system (enriched samples of evodiamine/PVP K(30)= 1/6, w/w) gave the highest dissolution rate: about 27.7-fold higher than that of enriched samples of evodiamine in hard capsules. Powder X-ray diffraction studies showed that enriched samples of evodiamine presented a total chemical stability after its preparation as solid dispersions. In vivo administration studies indicated that solid dispersions of evodiamine in hard capsules had a higher C(max) and a shorter T(max) than those of physical mixture in hard capsules, and the differences of C(max) and T(max) between them were significant. These results suggest that solid dispersions of evodiamine in hard capsules has a notably faster and greater absorption rate than enriched samples of evodiamine in physical mixture hard capsule and corresponds with the in vitro dissolution.     

Preparation and physicochemical characterizations of tanshinone IIA solid dispersion

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.