ABSTRACT
The treatment of brain tumors is greatly limited due to the presence of the blood-brain barrier/blood-brain tumor barrier. In recent years, the application of some new technologies has improved the permeability of the blood-brain barrier and improved the curative effect. However, malignant tumors cause the gap between the tight connections to be larger, and capillary leakage appears. Another barrier to glioma chemotherapy, the blood-brain tumor barrier, is formed among the leaky blood-brain barrier, the neovascular and malignant brain tumor tissues, which greatly limits the penetration and accumulation of drugs into the tumor. The author has reviewed relevant information at home and abroad in recent years, and then analyzed and summarized. This article not only analyzed the structural characteristics of the blood-brain tumor barrier, but also reviewed the technologies and methods which had been proved to improve the drug across the blood-brain tumor barrier such as drug combination, novel formulation technology, physical technology and biotechnology, aiming to explore the comprehensive treatment of brain tumors.
ABSTRACT
OBJECTIVE:To prepare Xuangui zhitong dispersible tablets and optimize its formulation technology. METHODS:Using disintegration time as index,single factor test was conducted for filler,disintegrating agent,the types and amount of adhe-sives and compression pressure. The amount of mixed disintegrating agent,avicel and gum arabic were optimized by orthogonal test. The tablet quality by optimized formulation was detected,and disintegration time,the content and dissolution rate of tetrahy-dropalmatine were determined;the similarity of in vitro dissolution rate of dispersible tablets and dropping pills were evaluated by similarity factor test. RESULTS:The optimized formulation was composed of 25% MCC as fillers,9% PVPP and 9% L-HPC as mixed disintegrants,85% ethanol solution as adhesives,micro-silica gel 2%,compression pressure of 3.0 kg/cm2. The average dis-integration time was 1.22 min,and the content of tetrahydropalmatine was 1.097 mg/g. The accumulative dissolution rate was more than 80% at 10 min and more than 90% at 15 min. The similarity factor f2 of dissolution curve was 62,using dropping pills as ref-erence preparation. CONCLUSIONS:Xuangui zhitong dispersible tablet had a rapid disintegration and the behavior of dissolution is similar to Xuangui zhitong dropping pills.
ABSTRACT
OBJECTIVE:To optimize the formulation technology of paeonol-?-cyclodextrin inclusion compound. METHODS: The formulation technology of paeonol-?-cyclodextrin inclusion compound was optimized by performing orthogonal experiment with the amount of ?-cyclodextrin,the solid-liquid ratio (ratio of ?-cyclodextrin to paeonol alcohol solution),the concentration of the envelop liquid (alcohol) as factors and the ultrasonic time was studied by single factor test and with the utilization ratio and entrapment efficiency of paeonol as indexes for evaluation. Meanwhile,a verification test was performed. RESULTS: The optimal formulation technology was as follows: the amount of ?-cyclodextrin was 8 g;the solid-liquid ratio was 1∶3;the concentration of the alcohol was 40% and the ultrasounding time was 40 min. The verification test revealed that the labeled contents were about 90% for all samples (4 batches). CONCLUSION: The optimized formulation technology is simple and reasonable,and it is applicable for the preparation of paeonol-?-cyclodextrin inclusion compound.
ABSTRACT
OBJECTIVE: To optimize the formula and preparation technology of gel-matrix sustained release tablet of nicotinic acid(GSTNA).METHODS: The formula of GSTNA was optimized by orthogonal experiment with the amount of hydrophilic gel-matrix material HPMC(K15M,E15-LV) and that of adjuvant calcium hydrogen phosphate(CHP) as factors and with the in vitro release rates as index.Meanwhile,the verification test on the intra-and inter-batch release rates of the samples was performed.RESULTS: The optimum formula could be seen as follows: the ratios of HPMC(K15M,E15-LV) and CHP were 4%,40% and 25% respectively.The GSTNA prepared in this formula achieved a sustained drug release of up to 12 h,and both the intra-batch homogenicity and the inter-batch reproducibility were satisfactory.CONCLUSION: The GSTNA is reasonable in formula and simple in preparation technology.