Preparation of mPEG2000-PLA-modified Xingnaojing microemulsion and evaluation in mucosal irritation

The influence of mPEG-PCL and mPEG-PLGA on encapsulation efficiency and drug-loading of SN-38 NPs

The influence of mPEG-PCL and mPEG-PLGA on encapsulation efficiency and drug-loading of nanoparticles was very important. SN-38 NPs were prepared from a series of diblock copolymers: mPEG1000-PLGA2000, mPEG2000-PCLs, mPEG5000-PCLs, mPEG2000-PLGAs, and mPEG5000-PLGAs by the thin film-hydration method. The prepared nanoparticles were characterized by morphology, size, encapsulation efficiency, drug-loading, and in vitro release behavior. This experiment suggested that the encapsulation efficiency and drug-loading of SN-38 NPs were attained the maximum values when the ratio of hydrophilic to hydrophobic block was between 1:2 and 1:3.

Discovery and Current Status of Evaluation System of Bioavailability and Related Pharmaceutical Technologies for Traditional Chinese Medicines--Flos Lonicerae Japonicae--Fructus Forsythiae Herb Couples as an Example

Traditional Chinese medicines (TCMs) have attracted extensive interest throughout the world due to their long history of health protection and disease control, and the internalization of TCM preparations or patented drugs has been considered a wind vane in the process of TCM modernization. However, multi-target effects, caused by multiple components in TCMs, hinder not only the construction of the quality evaluation system (bioavailability), but also the application of pharmaceutical technologies, which results in the poor efficacy in clinical practice. This review describes the methods in the literature as well as in our thoughts about how to identify the marker components, establish the evaluation system of bioavailability, and improve the bioavailability in TCM preparations. We expect that the current study will be positive and informative.

Xingnaojing mPEG2000-PLA modified microemulsion for transnasal delivery: pharmacokinetic and brain-targeting evaluation

Xingnaojing microemulsion (XNJ-M) administered intranasally is used for stroke treatment. In order to decrease the XNJ-M-induced mucosal irritation, XNJ-M modified by mPEG2000-PLA (XNJ-MM) were prepared in a previous work. The present work aimed to assess the impact of mPEG2000-PLA on pharmacokinetic features and brain-targeting ability of XNJ-M. The bioavailability and brain-target effects of borneol and geniposide in XNJ-M and XNJ-MM were compared in mice after intravenous (i.v.) and intranasal (i.n.) administrations. Gas chromatography, high-performance liquid chromatography, and ultra-performance liquid chromatography/tandem mass spectrometry methods were developed for the quantification of borneol and geniposide. Blood and brain samples were collected from mice at different time points after i.v. and i.n. treatments with borneol at 8.0 mg/kg, geniposide at 4.12 mg/kg. In addition, near-infrared fluorescence dye, 1,1'-dioctadecyl-3,3,3',3'-tetramethyl indotricarbocyanine iodide was loaded into microemulsions to evaluate the brain-targeting ability of XNJ-M and XNJ-MM by near-infrared fluorescence imaging in vivo and ex vivo. For XNJ-M and XNJ-MM, the relative brain targeted coefficients (Re) were 134.59% and 198.09% (borneol), 89.70% and 188.33% (geniposide), respectively. Besides, significant near-infrared fluorescent signal was detected in the brain after i.n. administration of microemulsions, compared with that of groups for i.v. administration. These findings indicated that mPEG2000-PLA modified microemulsion improved drug entry into blood and brain compared with normal microemulsion: the introduction of mPEG2000-PLA in microemulsion resulted in brain-targeting enhancement of both fat-soluble and water-soluble drugs. These findings provide a basis for the significance of mPEG2000-PLA addition in microemulsion, defining its effects on the drugs in microemulsion.