Preparation and in vitro evaluation of curcumin CTPP-PEG-PCL micelles / 中国中药杂志

To synthetize 3-carboxypropyl-triphenylphosponium bromide-polycaprolacton-CTPP-PEG-PC, and prepare curcumin CTPP-PEG-PCL micelles by using the self-assembled emulsion solvent evaporation method, in order to determine the critical micelle concentration (CMC) with the pyrene fluorescent probe technology, detect the particle size, entrapment efficiency (%), morpheme and in vitro release rate, and evaluate the cytotoxicity of hepatic stellate cells with MTT assay. The structure of CTPP-PEG-PCL had been identified by 1H-NMR spectra. Specifically, the CMC of polymer was 2.25 mg x L(-1), the average size was 190 nm, the drug content was (0.66 +/- 0.008) g x L(-1), and the entrapment efficiency was (94 +/- 0.6)%. The in vitro release results showed curcumin micelles had a significant higher inhibition ratio in the growth of hepatic stellate cells than crude curcumin (P < 0.05). This suggested that CTPP-PEG-PCL micelles feature low CMC, high encapsulation efficiency and notable inhibition effect in growth of hepatic stellate cells.

In situ rats single pass perfusion intestinal absorption of the effectivein components in Radix Angelicae Pubescentis / 药学学报

In order to study the intestinal absorption behaviors of three active constituents, columbianetin acetate, osthole and columbianadin in Radix Angelicae Pubescentis extracts, in situ rat single pass intestine perfusion (SPIP) was carried out by the perfusion solution of the extract I containing less than 10% total coumarins. The absorption of extract II containing more than 60% total coumarins was compared with that of extract I by rat colon SPIP to elucidate the influence on absorption of the different coumarin content extracts of the Chinese traditional medicine. The samples of the perfusion solution were collected in certain intervals. The concentrations of three active components in the perfusion samples were determined by HPLC method. The results demonstrated that the absorption rate constants (Ka) or apparent permeability coefficients (Papp) of columbianetin acetate, osthole and columbianadin from extract I had no significant difference among concentration ranges of 62-555 microg x mL(-1), 101-887 microg x mL(-1), 19-186 microg x mL(-1), respectively. The absorption quantity of three components was proportional to its concentration respectively and the saturate absorption phenomena were not observed. This suggested that the absorption of columbianetin acetate, osthole and columbianadin showed the passive diffusion process. Three components could be absorbed in whole intestinal sections. The Ka and Papp of three components all showed colon > duodenum > jejunum > ileum in four different regions of rat intestine. At colon, Ka and P app were significant different from the others. The Ka or Papp of three components from the extract I was significantly more than that of same components from extract II. The extract I redounded to increase the absorption of three active components.

Preparation and characterization of 7-ethyl-10-hydroxycamptothecin-loaded hypomicron of amphiphilic block copolymer / 药学学报

Methoxypolyethylene glycol-poly lactic acid (PELA) was synthesized by ring-opening copolymerization of lactide in the presence of mPEG and its structure was characterized by 1H NMR. The novel hypomicrons were prepared by solution-casting method using PELA block copolymer as a matrix and 7-ethyl-10-hydroxycamptothecin (SN-38) as an antitumor agent. The morphology, size and size distribution, drug loading, entrapment efficiency, and release characteristics in vitro of the SN-38 loaded hypomicrons were studied. The results showed that the obtained hypomicrons showed spherical shape with the core-shell structure, the sizes are in the range of 157-238 nm, and the drug loading content varied from 1.35%-3.58% depending on the copolymer composition and the SN-38 fed amount. The in vitro release behavior in phosphate-buffered saline, pH 7.4, exhibited a sustaining release manner and was affected by the copolymer composition. The drug-loaded amount and entrapment efficiency decreased with increasing the molecular weight of the copolymer. With the increasing of the SN-38 fed amount, the drug-loaded amount and the size of hypomicrons increased, the entrapment efficiency decreased. The SN-38 hypomicrons increased the solubility of SN-38 in water and were valuable for the development of the novel dosage form of SN-38.

The absorption characteristics of silybin in small intestine of rat / 药学学报

<p><b>AIM</b>To investigate the intestinal absorption of silybin (SLB) in male rats.</p><p><b>METHODS</b>Single-pass intestinal perfusion (SPIP) technique was performed in each isolated region of the small intestine at a flow rate of 0.1 mL x min(-1). The samples of perfusate and portal plasma were collected at the designated periods of time after rat intestinal perfusion and analyzed for drug by HPLC.</p><p><b>RESULTS</b>The absorption rate constant (k(a)) and the effective permeability (P(eff)) of SLB at 190 microg x mL(-1) were determined for each segment. These data indicated the absorption rate were duodenum > jejunum > ileum > colon. SPIP was also performed in duodenum with three concentrations of SLB (80, 190 and 300 microg x mL(-1)). The concentration dependent changes of k(a) and P(eff) were evident in the duodenum perfusion of silybin. At silybin perfusate concentrations of 80 microg x mL(-1), k(a) and P(eff) were different from the values at either of the two higher concentrations (190 and 300 microg x mL(-1), P < 0.05). However there was no difference between 190 microg x mL(-1) and 300 microg x mL(-1) groups. The drug mass appearing in the plasma further indicated the absorption were duodenum > jejunum > ileum > colon.</p><p><b>CONCLUSION</b>SLB can be absorbed in whole intestinal sections. When the concentration raises to a certain level, the uptake of SLB will not increase.</p>

Studies on the preparation of camptothecin niosomes / 药学学报

<p><b>AIM</b>To study the non-ion surfactant vehicle (niosome) entrapped-camptothecin.</p><p><b>METHODS</b>The niosome loaded with camptothecin was prepared from Span and cholesterol using aqueous dispersion of film. The vehicles were visualised by transmission electron microscopy and sized by laser particle analyzer on a Malvern Mastersizer. An HPLC analysis method of the camptothecin was established by fluorescence detection. The entrapment efficiency of the niosomes containing camptothecin was determinated after the ultracentrifugation of the niosome. The antitumor activities of the vehicles on S180 sarcoma in mouse were studied.</p><p><b>RESULTS</b>The given niosomes were the suspension finely dispersed in aqueous solution. They were spherical vehicles with the single lamellar bilayers similar to phospholipid vehicles. The mean sizes of the vehicles were (565 +/- 6) nm. The recovery of the HPLC analysis method was 100.3% with 0.4% RSD. The entrapment efficiency of the camptothecin encapsulated by the niosome was 61%. The inhibition (%) of the niosome loaded with camptothecin on S180 sarcoma in mouse were 76.1% (P < 0.05). After the given dose the weight of the mouse of the niosome groups were 92.7% (P > 0.05) and 134.7% of blank control groups and compatothecin solution groups, respectively.</p><p><b>CONCLUSION</b>The camptothecin niosomes were spherical in shape and similar to phospholipid vehicles with singlelamellar bilayers. Their size distributions were narrow. Their entrapment efficiency were higher. Its antitumor activity was better than camptothecin.</p>