Preparation of glycyrrhizic acid-F127/TPGS mixed nanomicelles and its in vivo intestinal absorption in rats / 中草药

Objective: To prepare glycyrrhizic acid (GL)-Pluronic F127 (F127)/polyethylene glycol 1000 vitamin E succinate (TPGS) mixed nanomicelles (MMs) and improve oral absorption of GL. Methods: GL-F127/TPGS-MMs was prepared by thin film dispersion method. The encapsulation efficiency and drug loading of MMs were used as evaluation indexes. The formulation and process, including the ratio of F127 to TPGS, the concentration of polymer and GL, hydration temperature and time, were optimized by the single factor experiment. The morphology of MMs was investigated by transmission electron microscopy. The single-pass perfusion model was established in rats to investigate the intestinal absorption characteristics of GL-F127/TPGS-MMs with absorption rate constant (Ka) and apparent absorption coefficient (Papp) as evaluation indexes. Results: The optimal formulation and process of GL-F127/TPGS-MMs were as follows: TPGS 180 mg, F127 270 mg, GL 70 mg, hydration temperature 50 ℃ and hydration time 3 h. The prepared GL-F127/TPGS-MMs had good clarity and the particle size, polydispersity index, and Zeta potential were (28.20 ± 5.63) nm, 0.20 ± 0.06, and (-5.24 ± 1.55) mV, respectively. The encapsulation efficiency and drug loading were (97.57 ± 5.29) % and (13.13 ± 0.71) %, respectively. The MMs were spherical with distinct vesicle structure. The absorption of GL in the jejunum segment was significantly higher than that in the ileum segment (P < 0.05). Compared with raw GL, GL-F127/TPGS-MMs had a statistically significant higher absorption rate in the intestinal segment (P < 0.05). Conclusion: The prepared GL-F127/TPGS-MMs could significantly improve the absorption of GL in vivo.

Preparation and in vitro evaluation of pH-sensitive drug releasing As2O3-loaded liposome / 中草药

Objective: To prepare pH-sensitive drug releasing As2O3 loaded liposome (CaAs-LP) and evaluate it in vitro. Methods: CaAs-LP was prepared by thin film dispersion and ion precipitation method. The particle size, PDI, and Zeta potential of CaAs-LP were measured by Malvern particle size analyzer; The morphology of the liposome was investigated by transmission electron microscopy; The drug loading and entrapment efficiency of CaAs-LP by inductively coupled plasma emission spectrum. In vitro release characteristics of CaAs-LP under different pH conditions were investigated by dialysis bag method. MTT assay was used to investigate the toxicity of carrier and CaAs-LP to MCF-7, U87 and HepG2 cells. Results: The prepared CaAs-LP were spherical and well-dispersed with particle size of (117.16 ± 1.94) nm. The encapsulation efficiency and the drug loading rate of CaAs-LP were (74.31 ± 2.11)% and (8.31 ± 0.13)%, respectively. In vitro release studies showed that CaAs-LP had the characteristics of sustained release and pH sensitive drug release, which can achieve specific drug release in the tumor environment. The carrier displayed remarkable biocompatibility in MCF-7, U87, HepG2 and L02 cells. MTT assay showed that the median lethal concentrations (IC50 values) of MCF-7, U87 and HepG2 cells were 11.91, 4.90 and 19.41 μmol/L, while L02 was 27.59 μmol/L, respectively, which showed strong inhibiting effect on tumor cells. Conclusion: CaAs-LP reveals significantly sustained and pH sensitive release characteristics. CaAs-LP is a potential drug delivery system against solid tumor with tumor micro-environment responsive.

Optimization of pH response and mitochondrial targeting bifunctional hyperoside liposomes by central composite design response surface methodology and its in vitro evaluation / 中草药

Objective: To optimize preparation of mitochondrial targeting hyperoside liposomes (DLD/Hyp-Lip), and study its stability in fetal bovine serum, in vitro release behavior and mitochondrial targeting. Methods: DLD/Hyp-lip was prepared by film dispersion method. Single factor experiment was carried out with entrapment efficiency and drug loading as indexes to investigate the effects of the ratio of phospholipids to hyperoside (Hyp) and DSPE-PEG (distearoyl phosphoethanolamine-polyethylene glycol) to DLD on DLD/Hyp-Lip. The formulation of DLD/Hyp-Lip was further optimized by central composite design response surface methodology. The appearance, size and potential of liposomes were observed by transmission electron microscope and particle size analyzer. The stability and drug release rate of liposomes in fetal bovine serum were evaluated by serum stability test and in vitro drug release test. The drug delivery system was evaluated by mitochondrial targeting. Results: The optimal formula of DLD/ Hyp-Lip was as follows: the ratio of total phospholipids to hyperoside was 12.50:1, the ratio of total phospholipids to cholesterol was 6.00:1, and the dosage ratio of DSPE-PEG to DLD was 3:5, the encapsulation efficiency was (95.57 ± 0.56) %, the drug loading was (8.55 ± 0.57) %. The prepared liposomes had good appearance, the particle size of the lip was (124.9 ± 3.4) nm, and the potential was (-6.2 ± 1.9) mV. It was stable in fetal bovine serum and accumulated in vitro release medium for 24 h. Mitochondrial targeting experiments showed that DLD/Hyp-Lip could promote the accumulation of drugs in the mitochondria. Conclusion: This method is simple and convenient, and can accurately and effectively optimize the preparation process of DLD/Hyp-Lip. The prepared DLD/Hyp-Lip has high encapsulation efficiency, small particle size, uniform distribution and good sustained-release effect, which lays the foundation for further in vivo research of DLD/Hyp-Lip. DLD/Hyp-Lip with hyperoside has good mitochondrial targeting of liver cancer cells and is a potentially efficient mitochondrial targeted drug delivery system for liver cancer cells.

mV, respectively, and the encapsulation efficiency and drug loading content were 87.9% and 0.57%. The final concentration of LM was 63.4 μg/mL. The release results showed 58.59% drug was released in 12 h. MTT results showed that the IC50 of LM@Lip on HepG2 and A549 cells was 20.16 and 15.39 μg/mL, respectively, and its in vitro antitumor was superior to that of LM. Conclusion Liposomes can increase the stability and solubility of LM. LM@Lip showed slow-release profile and significant tumor inhibition superior to LM. Key words: limonin; liposomes; thin-film dispersion method; orthogonal experiment; in vitro release; antitumor; druggability / 中草药

Objective: In view of druggability issue of limonin (LM), the liposomal preparation was developed. The liposomal formulation and preparation process were optimized, and its in vitro antitumor activity was investigated. Methods: In this study, LM was loaded in liposomes to increase its stability and solubility. Meanwhile, in vitro cytotoxicity of LM@Lip was evaluated. LM@Lip were prepared by thin-film dispersion method, and formulation selection and process optimization were operated by single factor and orthogonal experiment. Size distribution, PDI and zeta potential were measured by Malvern sizer, and the encapsulation efficiency and drug loading content were determined by HPLC. The dialysis method was used to investigate the release profile of LM@Lip. In vitro cytotoxicity against HepG2 and A549 cells were estimated by MTT method. Results: The optimized preparation conditions of liposomes were as follows: drug/lipid ratio was 1:150, cholesterol/lipid ratio was 1:9, the ultrasonic power was 120 W for 6 min (1 s interval). The average particle size, PDI and Zeta potential of optimized LM@Lip were (119.5 ± 6.2) nm, 0.318 ± 0.124, (-17.2 ± 1.3) mV, respectively, and the encapsulation efficiency and drug loading content were 87.9% and 0.57%. The final concentration of LM was 63.4 μg/mL. The release results showed 58.59% drug was released in 12 h. MTT results showed that the IC50 of LM@Lip on HepG2 and A549 cells was 20.16 and 15.39 μg/mL, respectively, and its in vitro antitumor was superior to that of LM. Conclusion: Liposomes can increase the stability and solubility of LM. LM@Lip showed slow-release profile and significant tumor inhibition superior to LM.

Effect of curcumin-micelles adopting vitamin E-TPGS and Solutol HS 15 as carriers on solubility and oral bioavailability of curcumin / 中草药

Objective: To prepare curcumin-micelles adopting vitamin E-TPGS (VE-TPGS) and Solutol HS15 (SHS15) as carriers, and study the effect on solubility and oral bioavailability of curcumin (Cur). Methods: Cur was loaded into micelles between VE-TPGS and SHS15 by thin film dispersion method. Particle size, loading efficiency, entrapment efficiency, and in vitro release were carried on to estimate the influence of micelles on Cur; Moreover, oral bioavailability in rats was also evaluated. Results: The particle size was (35.79 ± 1.23) nm with polydispersity index (PDI) of 0.12 ± 0.03 when the optimized micelles ratio was at 3:7 of VE-TPGS and SHS15, which increased the solubility of Cur to 2.03 mg/mL in water. The entrapment efficiency and drug loading were 90.03% and 9.34%, respectively. The in vitro release profile showed a sustained release property compared with that of Cur. In addition, the relative bioavailability of micelles (AUC0~∞) compared with that of Cur (AUC0~∞) was 303.5% (P < 0.01). Conclusion: The Cur-micelles combined use of VE-TPGS and SHS15 shows great potential clinical application.

Study on preparation of Panax notoginseng saponins transfersomes and their effects on acute soft tissue injury in rats / 中草药

Objective: To optimize the formulation of Panax notoginseng saponins (PNS) transfersomes and to verify their effects on acute soft tissue injury in rats. Methods: Thin film dispersion method was employed to prepare PNS transfersomes. Based on the elasticity of transfersomes, PNS transfersomal formulation was optimized by a uniform experimental design. Extrusion method and centrifugation-ultrafiltration method were respectively adopted to determine the elasticity and the entrapment efficiency (EE) of PNS transfersomes. The therapeutic effects of PNS transfersomes on acute soft tissue injury in rats were evaluated by observing the indexes of injury symptom, the hemorheology and the histomorphology with Qingpeng Ointment being used as positive control. Results: The optimum formulation was as follows: PNS 100 mg, cholesterol 15 mg, soybean phospholipid 120 mg, vitamin E 2 mg, volatile oils (limonene-citral = 4:1) 80 mg, and hydration liquid (phosphate buffered saline, pH 5.0) 10 mL. The optimized PNS transfersomes had elasticity of (2.74 ± 0.32) min, average size of (123.6 ± 0.36) nm, Zeta potential of (-36.67 ± 2.29) mV, and EE of (82.42 ± 0.69)% and (94.40 ± 0.74)% for ginsenoside Rg1 and ginsenoside Rb1, respectively. The results of pharmacodynamical tests showed that the PNS transfersomes could significantly improve the injury symptom indexes (P < 0.01) and hemorheology (P < 0.05) of the rats compared with model control, and it could also improve their histomorphology. Conclusion: The optimized PNS transfersomes with an appropriate size, desired elasticity, and drug EE are effective for the acute soft tissue injury in rats.

Optimization of glycyrrhizic acid bile salt/phospholipid mixed micelles fast dissolving sublingual films by response surface method / 中草药

Objective: To prepare and optimize glycyrrhizic acid bile salt/phosphatidylcholine mixed-micelles fast dissolving sublingual films (GL-BS/PC-MM-FDSFs) and preliminarily evaluate its mucous membrane permeation in vitro. Methods: The formulations of GL-BS/PC-MM-FDSFs were optimized by employing Box-Behnken design-response surface methodology with the amounts of sodium alginate, propylene glycol, and GL-BS/PC-MM as investigation factors, and the disintegration time, cumulative release of drug from the GL-BS/PC-MM-FDSFs within 5 min, and particle size of reconstituted MM from GL-BS/PC-MM-FDSFs as indexes. Mucous membrane permeation test was evaluated in vitro with porcine sublingual mucosa as a model by using Franz diffusion cell. Results: The GL-BS/PC-MM-FDSFs prepared by optimized formulation (23 g/L sodium alginate, 148.5 g/L propylene glycol, and 7.58 mL GL-BS/PC-MM) could fast disintegrate in (22.1 ± 0.7) s, release in vitro at 5 min to (85.30 ± 2.91)%, and the particle size of reconstituted MM from GL-BS/PC-MM-FDSFs was obtained as (146.46 ± 6.42) nm. There was a little deviation between the theoretically predicted value and measured value. It showed that this model had a good prediction. There was no significant difference between the accumulative permeation profiles of GL-BS/PC-MM-FDSFs and GL-BS/PC-MM at each time point. Conclusion: The process that GL-BS/PC-MM is solidified to GL-BS/PC-MM-FDSFs is simple and feasible, and GL-BS/PC- MM-FDSFs could significantly improve the mucous membrane absorption of GL.