卡维地洛固体分散体的制备及其体外溶出度的测定

目的 :制备卡维地洛固体分散体 ,提高其溶解度和溶速率。方法 :以聚乙烯吡咯烷酮 (PVP)、聚乙二醇 -6000(PEG -6000)为载体 ,以溶剂法和熔融法制备固体分散体 ,并进行体外溶出度研究。结果 :载体比例越大 ,药物溶出愈快 ;载体比例愈小 ,差异愈显著。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 -6000的固体分散体。结论 :本试验所制卡维地洛固体分散体能加速体外溶出 ,提高生物利用度 ,可用于制备高效制剂     

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     

硝苯地平固体分散体制备工艺的研究

目的利用固体分散技术将硝苯地平制成固体分散体,提高其体外溶出速率。方法分别以聚乙二醇6000(PEG6000)、聚乙二醇4000(PEG4000)、聚乙烯吡咯烷酮K30(PVPK30)、泊洛沙姆188(Pluronic F68)等为载体,用熔融法、溶剂法、溶剂-熔融法和喷雾干燥法制备硝苯地平固体分散体。采用差热分析法(DTA)分析药物在固体分散体中的存在状态,并进行体外溶出度试验。结果各种固体分散体均能加快药物的溶出速率,并且随着载体在固体分散体中的比例增大,溶出速率增大。DTA分析显示硝苯地平在PVPK30的固体分散体中以微细结晶存在。结论将硝苯地平制成固体分散体能显著提高硝苯地平的体外溶出速率。     

硝苯地平固体分散体制备工艺的研究

目的利用固体分散技术将硝苯地平制成固体分散体,提高其体外溶出速率。方法分别以聚乙二醇6000(PEG6000)、聚乙二醇4000(PEG4000)、聚乙烯吡咯烷酮K30(PVPK30)、泊洛沙姆188(Pluronic F68)等为载体,用熔融法、溶剂法、溶剂-熔融法和喷雾干燥法制备硝苯地平固体分散体。采用差热分析法(DTA)分析药物在固体分散体中的存在状态,并进行体外溶出度试验。结果各种固体分散体均能加快药物的溶出速率,并且随着载体在固体分散体中的比例增大,溶出速率增大。DTA分析显示硝苯地平在PVPK30的固体分散体中以微细结晶存在。结论将硝苯地平制成固体分散体能显著提高硝苯地平的体外溶出速率。     

尼莫地平固体分散物的制备及其片剂溶出度的研究

目的：提高难溶性药物尼莫地平的溶出速率。方法：选用PVP－k30和PEG6000为载体制备了不同晶型尼莫地平固体分散物和机械混合物，比较了它们片剂体外的溶出速率。结果：尼莫地平固体分散物的片剂溶出度高于机械混合物的，低熔点机械混合物片剂溶出度高于高熔点的，不同晶型尼莫地平PEG6000固体分散物片剂体外的溶出速率无显著性差异，低熔点尼莫地平PVK－k30固体分散物的片剂的90min累积溶出量比高熔点的高。结论：不同晶型尼莫地平制备成PVP-k30和PEG6000固体分散物都可以提高其片剂体外的溶出度。     

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。     

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。     

浙贝提取物固体分散体的制备及溶出特性研究

目的：制备浙贝提取物固体分散体,考察其中贝母素甲及贝母素乙的溶出效果,从而确定制备的最佳方法和最佳比例。方法：选择聚乙二醇6000（PEG6000）与聚乙烯吡咯烷酮（PVP K30）两种载体材料,分别采用熔融法和溶剂法制备浙贝提取物固体分散体;通过比较提取物、固体分散体的溶出性能,确定最佳工艺。结果：使用HPLC-ELSD法测定贝母素甲及贝母素乙的溶出量,结果准确、可靠、稳定。制备成固体分散体能显著提高贝母素甲及贝母素乙的体外溶出速度;PEG6000作为载体的浙贝提取物固体分散体溶出速度快于PVP K30为载体的浙贝提取物固体分散体。结论：以PEG6000为载体,采用熔融法制备的药物/载体比例为1∶6的固体分散体能显著提高浙贝提取物中贝母素甲及贝母素乙的溶出速率。     

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。     

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.     

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.     

Solid dispersion of carbamazepine in PVP K30 by conventional solvent evaporation and supercritical methods

This study compares the physicochemical properties of carbamazepine (CBZ) solid dispersions prepared by either a conventional solvent evaporation versus a supercritical fluid process. Solid dispersions of carbamazepine in polyvinylpyrrolidone (PVP) K30 with either Gelucire 44/14 or Vitamin E TPGS, NF (d-alpha-tocopheryl polyethylene glycol 1000 succinate) were prepared and characterized by intrinsic dissolution, differential scanning calorimetry, powder X-ray diffraction and Fourier transform infrared spectroscopy. CBZ/PVP K30 and CBZ/PVP K30/TPGS solid dispersions showed increased dissolution rate. The best intrinsic dissolution rate (IDR) was obtained for supercritically processed CBZ/PVP K30 that was four-fold higher than pure CBZ. Thermograms of various solid dispersions did not show the melting peak of CBZ, indicating that CBZ was in amorphous form inside the carrier system. This was further confirmed by X-ray diffraction studies. Infrared spectroscopic studies showed interaction between CBZ and PVP K30 in solid dispersions. The amorphous state of CBZ coupled with presence of interaction between drug and PVP K30 suggests fewer, if any, stability problems. Because the supercritical-based process produced solid dispersions with IDR better than conventional solid dispersions augmented with amphiphilic carriers, stability issues associated with lipid carriers do not apply, which, in turn, implies easier scale up under current Good Manufacturing Practice for this technique.     

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     

Studies on aging piroxicam-polyvinylpyrrolidone solid dispersions

The stabilities of X-ray amorphous solid dispersions of piroxicam and polyvinylpyrrolidone (PVP) K-17 and PVP K-30 (1:5 and 1:4), respectively, were investigated after storage for 12 months. X-ray diffraction showed that in the aged solid dispersions piroxicam remained in the amorphous state. Fourier transform infrared (FTIR) spectroscopy indicated that the interactions between drug and PVP in aged solid dispersions are similar to those in freshly prepared samples. The dissolution rates of the X-ray amorphous solid dispersions during storage for 12 months at 45 degrees C and ambient temperature were examined. Very minor decreases in dissolution rates of aged solid dispersions were found which might be due to the coarsening of the particles. Dissolutions of these amorphous solid dispersions after aging for 12 months still showed an about 40-fold increase in dissolution in 5 min compared to pure drug.     

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。     

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.