氯诺昔康固体分散体的热焓变化及溶出度改善特性

目的：制备非甾体抗炎药氯诺昔康的固体分散体以提高难溶性氯诺昔康体外溶出速率。研究载体类型及药物-载体混合比例对固体分散体体外溶出速率的影响,并根据：DSC测定结果考察各种混合物中氯诺蕾康热焓变化的特性。方法：分别以Poloxamer188、PVPK30和Gelucire 44／14为载体,采用溶剂蒸发法制备氯诺昔康固体分散体。采用浆法进行体外溶出度试验。根据DSC实测数据考察热焓变化特征。结果：固体分散体体外溶出速率的先后顺序为PXM,PVP,GLC,物体混合物顺序为PXM,GLC,PVP,随着载体比例的增加,PVP和泊洛沙姆固体分散体溶出速率常数增加。DSC圈谱表明,随着载体比例的增加,氯诺昔康放热峰的起始温度和△H降低,当氯诺昔康的泊洛沙姆比例为1：10时,药物以无定形状态存在于结晶性的泊洛沙姆中,从而使其在体外具有最快的溶出速率。结论：载体类型及药物-载体比例影响氯谱诺昔康固体分散体的体外溶出特性及热焓变化。     

Protein–nanoparticle interactions evaluation by immunomethods: Surfactants can disturb quantitative determinations

The adsorption of proteins on nanoparticle surface is one of the first events that occur when nanoparticles enter in the blood stream, which influences nanoparticles lifetime and further biodistribution. Albumin, which is the most abundant protein in serum and which has been deeply characterized, is an interesting model protein to investigate nanoparticle–protein interactions. Therefore, the interaction of nanoparticles with serum albumin has been widely studied. Immunomethods were suggested for the investigation of adsorption isotherms because of their ease to quantify the non-adsorbed bovine serum albumin without the need of applying separation methods that could modify the balance between the adsorbed and non-adsorbed proteins. The present work revealed that this method should be applied with caution. Artifacts in the determination of free protein can be generated by the presence of surfactants such as polysorbate 80, widely used in the pharmaceutical and biomedical field, that are needed to preserve the stability of nanoparticle dispersions. It was shown that the presence of traces of polysorbate 80 in the dispersion leads to an overestimation of the amount of bovine serum albumin remaining free in the dispersion medium when determined by both radial immunodiffusion and rocket immunoelectrophoresis. However, traces of poloxamer 188 did not result in clear perturbed migrations. These methods are not appropriate to perform adsorption isotherms of proteins on nanoparticle dispersions containing traces of remaining free surfactant. They should only be applied on dispersions that are free of surfactant that is not associated with nanoparticles.