Effects of HPMCAS MF on absorption of silybin from supersaturable self-nanoemulsifying drug delivery system / 中国中药杂志

To evaluate the effects of Hydroxypropyl methylcellulose acetate succinate(HPMCAS MF) on absorption of silybin(SLB) from supersaturable self-nanoemulsifying drug delivery system which was pre-prepared at the early stage experiment. The cell toxicity of self-emulsifying preparation was evaluated by the MTT method, and the in vitro membrane permeability and absorption promoting effect of the self-emulsifying preparation were evaluated by establishing a Caco-2 cell monolayer model. The in vivo and in vitro supersaturation correlation was evaluated via the blood concentration of SLB. The results of MTT showed that the concentration of the preparation below 2 mg·mL~(-1)(C_(SLB) 100 μg·mL~(-1)) was not toxic to Caco-2 cells, and the addition of polymer had no significant effect on Caco-2 cells viability. As compared with the solution group, the transport results showed that the P_(app)(AP→BL) of the self-emulsifying preparation had a very significant increase; the transport rate of silybin can be reduced by polymer in 0-30 min; however, there was no difference in supersaturated transport between supersaturated SLB self-nanoemulsion drug delivery system(SLB-SSNEDDS) and SLB self-nanoemulsion drug delivery system(SLB-SNEDDS) within 2 hours. As compared with SLB suspension, pharmacokinetic parameters showed that the blood concentration of both SLB-SNEDDS and SLB-SSNEDDS groups were significantly increased, and C_(max) was 5.25 times and 9.69 times respectively of that in SLB suspension group, with a relative bioavailability of 578.45% and 1 139.44% respectively. C_(max) and relative bioavailability of SLB-SSNEDDS were 1.85 times and 197% of those of SLB-SNEDDS, respectively. Therefore, on the one hand, SSNEDDS can increase the solubility of SLB in gastrointestinal tract by maintaining stability of SLB supersaturation state; on the other hand, the osmotic transport process of SLB was regulated through the composition of its preparations, and both of them could jointly promote the transport and absorption of SLB to improve the oral bioavailability of SLB.

Formulation optimization of andrographolide self-nanoemulsifying drug delivery system and effect of precipitation inhibitor on its phase behavior / 中草药

Objective: To investigate the effect of HPMC, PVP k30 and PEG 4000 on the phase behavior of andrographolide self-nanoemulsifying drug delivery system (AG-SNEDDS) dispersed in Fasted-state simulated intestinal fluid (FaSSIF). Methods: The preparation technology of andrographolide AG-SNEDDS was optimized by central composite design. The effect of three types of precipitation inhibitors (PVP-k30, HPMC, PEG 4000) on the supersaturation behavior of AG-SNEDDS dispersed in FaSSIF was investigated with the degree of supersaturation as an evaluation index. The precipitated phase was evaluated by polarized light microscopy (PLM). Results: The results showed that the best prescription of AG-SNEDDS was Capryol 90-Cremophor EL:Tween-20 (1:1)-Transcutol HP (12.9:40.5:46.6). The self-microemulsion was uniform, the drug loading was (6.93 ± 0.04) mg/g. The emulsification time was (22.33 ± 0.33) s, the average particle size was (14.25 ± 0.65) nm. HPMC and PEG 4000 can maintain the supersaturation of AG-SNEDDS after being dispersed in FaSSIF, and the effect was positively correlated with their concentration. As for PVP k30, it reduced the degree of supersaturation at a low concentration, but can maintain supersaturation at medium and high concentration. Using any of the three precipitation inhibitors can reduce the particle size of the precipitated particles. Conclusion: Precipitation inhibitors can maintain the supersaturation of AG when disperse AG-SNEDDS in FaSSIF. The ability to maintain supersaturation varies with the types and concentration of precipitation inhibitor.

Influence of sonication and in vitro evaluation of nifedipine self-nanoemulsifying drug delivery system

In order to develop a self-nanoemulsifying system, three components, olive oil, Tween 80, and Capmul, were used to construct a ternary phase diagram that helped to find the optimum formulation, which was loaded with nifedipine. The effect of sonication on drug loading was also evaluated. After that, measurement of the droplet size, size distribution, zeta potential, and scanning electron microscopy were conducted for evaluation and characterisation of the formulations. The phase diagram of four formulations showed nanosizes below 200 nm; however, only one was selected to be loaded with nifedipine. The selected formulation had the lowest droplet size of 98 nm and size distribution 0.192, and was composed of 48% Tween 80, 32% Capmul, and 20% olive oil. The nifedipine self-nanoemulsifying drug delivery system (SNEDDS) showed a significant change in the particle size (97 nm) and size distribution (0.257) after sonication. Its zeta potential was -32.3 mV indicating good stability. The SEM photographs of nifedipine showed particles with spherical shape and smooth surface. Finally, a self-nanoemulsifying formulation containing nifedipine, loaded in olive oil, was successfully prepared by mixing the oil with various types of surfactants and co-surfactants. A significant nifedipine self-nanoemulsifying system was developed and significantly improved accordingly.

Drug distribution during in vitro lipolysis of SNEDDSs containing griseofulvin / 中国药学杂志

OBJECTIVE: To establish and optimize in vitro lipolysis model, and then to study griseofuvin(GRI) distribution during in vitro lipolysis of self-nanoemulsifying drug delivery systems(SNEDDSs). METHODS: The lipolysis rate and extent of triglyceride (TG)were two index for in vitro lipolysis model optimization. The partitioning of GRI into lipolysis phases (aqueous phase, pellet phase, lipid phase) was exploited to investigate the impact of structure and lipid loaded of TG on GRI distribution of SNEDDSs in vitro lipolysis. RESULTS: The optimal lipolysis model at the start of the experiment was as follows: 800 U · mL-1 Pancreatin extract, 5/1.25 mmol · L-1 NaTDC/PC micelle and 50 mmol · L-1 Trizma maleate. The addition way of Ca2+ for medium chain triglyceride (MCT) and long chain triglyceride (LCT) were fixed addition 5 mmol · L-1 and continuous addition 0.008 mmol · min-1, respectively. With the same amount of TG in SNEDDSs, percent content of GRI in aqueous phase of LCT-SNEDDS was higher than MCT-SNEDDS. When TG loaded doubled, GRI in aqueous phase of LCT-SNEDDS significantly increased by 32.4%, and which of MCT-SNEDDS raised only 5.7%, respectively. CONCLUSION: The lipolysis rate and extent of TG were correlated with its structure and composition of TG and in vitro lipolysis model. Compared to GRI-SNEDDS without lipolysis, during in vitro lipolysis GRI had transferred to aqueous phase, pellet phase and lipid phase from which was only dispersed in emulsion droplet. And the distribution of GRI during in, vitro lipolysis depended on the composition and loading rate of TG in SNEDDS. These results may provide useful references to study the absorption mechanism of SNEDDS.