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OBJECTIVE： To optimize the preparation technology of Oridonin A oral liposomes （ORI-LIP） by using supercritical fluidsolution-enhanced dispersion （SEDS） technology， and to investigate its advantage with routine liposome preparation technologies. METHODS： Using particle size as evaluation index， orthogonal design was employed to investigate the influence of pressure， temperature and flow rate on the preparation technology of ORI-LIP by SEDS. At the same time， thin film dispersion and reverse evaporation method were used to prepare ORI liposomes. The particle size， encapsulation efficiency， drug loading amount and stability （accelerated test for 6 months） were compared among 3 methods. Moreover， the difference in dissolution behavior in vitro of ORI crude drug and 3 kinds of liposomes was evaluated. RESULTS： The optimized preparation condition of ORI liposomes by SEDS included temperature of 50 ℃， pressure of 18 MPa， flow rate of 1 mL/min. Compared with thin film dispersion and reverse evaporation method， the liposomes prepared by the SEDS method exhibited smaller particle size [（147.4±4.8）nm]， better encapsulation efficiency （67.8％）， drug-loading amount （7.8％） and stability （particle size increased slightly， encapsulation efficiency decreased only by 4.4％）. Results of in vitro dissolution test showed that compared with crude drug， release rate of each liposome was slow and persistent， and the cumulative release rate was higher. The accumulative release rate of ORI-LIP prepared by SEDS could achieve to 67.2％， and reached to dissolution equilibrium at 24 h. CONCLUSIONS： ORI-LIP prepared by SEDS has smaller particle size， higher encapsulation efficiency， drug loading amount and stability， which can improve the in vitro release of ORI. Compared with conventional methods， SEDS technology has certain advantages.
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OBJECTIVE： To establish a methaod for content determination of doxorubicin hydrochloride nano-liposomes， and to optimize its preparation technology. METHODS： The contents of doxorubicin hydrochloride nano-liposomes was determined by UV spectrophotometry. The membrane dispersion method was used to prepare doxorubicin hydrochloride nano-liposomes. Using particle size， encapsulation efficiency and drug-loading amount as indexes， the weight ratio of phospholipid to drug （mg/mg）， the weight ratio of phospholipid to cholesterol （mg/mg） and ultrasonic time （min） as factors， central composite design-response surface methodology was used to optimize the preparation technology. The photothermal conversion effect of doxorubicin hydrochloride nano-liposomes was investigated by near infrared irradiation. RESULTS： The linear range of doxorubicin hydrochloride were 1.01-16.16 μg/mL（r＝0.999 7）； precision， stability and reproducibility tests were all in line with the requirments of Chinese Pharmacopoeia. The optimal preparation technology included that the weight ratio of phospholipid to drug was 13.30 ∶ 1（mg/mg）； the weight ratio of phospholipid to cholesterol was 4.09 ∶ 1 （mg/mg）； the ultrasonic time was 10 min. Under this technology， the particle size and drug-loading amount of doxorubicin hydrochloride nano-liposomes were （200.5±25.1） nm and （11.02±0.20）％， relative errors of which to predicted value （196.3 nm， 10.68％） were 1.82％ and 1.63％. The consistency between measured value and predicted value was good. Doxorubicin hydrochloride nano-liposomes exhibited concentration- dependent and time-dependent photothermal conversion characteristics under near infrared irradiation at 808 nm. CONCLUSIONS： Established method is simple and good accuracy. The optimized preparation technology is simple and feasible.
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OBJECTIVE: To prepare zedoary turmeric oil compound liposomes (ZTOC-LPS) and evaluate its quality.METHODS: The preparation method of liposome, the addition amount of soybean phosphatidylcholine (SPC), ratio of SPC to cholesterol (CH) in lipid, drug-lipid ratio of zedoary turmeric oil (ZTO), drug-lipid ratio of tretinoin in formulation, and water bath temperature were screened using encapsulation efficiency and drug-loading amount of ZTO (represented by germacrone) and tretinoin as investigation indexes. Quality evaluation and primary stability investigation were conducted for liposomes prepared by optimal preparation technology. RESULTS: The optimal preparation method was ethanol injection method; The optimal preparation technology were SPC 4 mg in 1 mL lipid, the mass ratio of SPC to CH 3:1, the ratio of ZTO to lipid 1:9, the ratio of tretinoin to lipid 1:70, water bath temperature of 55 ℃. Encapsulation efficiencies of ZTO and tretinoin were (64. 63 ± 1. 00)％ and (90. 33 土 0. 72)％ in 3 batches of ZTOC-LPS, respectively. Drug-loading amount of ZTO and tretinoin were (9. 09 ± 0. 14)％ and (1. 43 ± 0. 02)％, respectively. Particle size was (257. 41 ± 7. 58) nm, Zeta potential was (-38. 77 ± 0. 81) mV,PDI was 0. 10 ± 0. 04; the results of centrifugal acceleration test showed that the liposomes had good physical stability. No obvious change was found in each investigation index of ZTOC-LPS that stored at (4 ± 2) ℃ for 1 month. CONCLUSIONS: Established preparation technology is simple and feasible, the quality of the prepared ZTOC-LPS conforms to the requirements, and it can provide reference for the following research of ZTOC-LPS.
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OBJECTIVE:To prepare redox-responsive pluronic F127 micelles with high drug-loading efficiency. METHODS:The thiol derivative F127-SH with strong hydrophobicity was synthesized by introducing tert-butyl methacrylate and cysteamine to the hydrophobic segments of F127. Paclitaxel (PTX)-loaded redox-responsive pluronic F127 micelles with high drug-loading effi-ciency(F127-SS/PTX)were prepared by film-hydration method as well as oxidation reaction of thiol groups. The diameter,encap-sulation efficiency and drug-loading amount were detected,and the change of diameter and drug release behavior of micelles were investaged under reducing environment or non-reducing environment. RESULTS:Mean diameter of F127-SS/PTX micelles was about(77.87±1.79)nm,and encapsulation efficiency and drug-loading amount were(92.73±2.35)% and(16.25±0.99)%,re-spectively. The diameter of the micelles increased rapidly and drug release rate of PTX increased significantly in the presence of 10 mmol/L dithiothreitol. CONCLUSIONS:The redox-responsive pluronic F127 micelles with high drug-loading efficiency are pre-pared successfully.
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OBJECTIVE:To evaluate the quality of solid lipid nanoparticle of the skin extract of Bufobufo gargarzans. METH-ODS:The morphology of solid lipid nanoparticle of the skin extract of B. gargarzans was observed by TEM. The particle size was determined by laser scattering particle size analyzer. The contents of cinobufagin and resibufogenin, encapsulation efficiency, drug-loading amount and accumulative release rate of cinobufagin were determined by HPLC. The stability of nanoparticle was in-vestigated within 24 h at 60,25 and 4 ℃. RESULTS:The solid lipid nanoparticle of the skin extract of B. gargarzans were uni-form in particle size and showed round and spheroidicity shape;average particle size was(138.5±4.2)nm,The encapsulation effi-ciency of cinobufagin and resibufogenin were 90.60% and 91.51%,and drug-loading amount were 35.82% and 44.15%. The accu-mulative release rate of cinobufagin was 50%at 4 h and reached 88%at 48 h,which was in line with Weibull equation(r=0.9438). Under 3 kinds of temperature conditions,encapsulation efficiency decreased gradually as the holding time of nanoparticle pro-longed;the decrease degree was the smallest at 4 ℃.CONCLUSIONS:The quality evaluation results of solid lipid nanoparticle of the skin extract of B. gargarzans are in line with the standard,and prepared nanoparticles show sustained-release effects and should be kept under low temperature.