Co-amorphous technology to improve dissolution and physical stability of silybin / 中国中药杂志

The present study explored the effect of co-amorphous technology in improving the dissolution rate and stability of silybin based on the puerarin-silybin co-amorphous system prepared by the spray-drying method. Solid-state characterization was carried out by powder X-ray diffraction(PXRD), polarizing microscopy(PLM), Fourier transform infrared spectroscopy(FT-IR), differential scanning calorimetry(DSC), etc. Saturated powder dissolution, intrinsic dissolution rate, moisture absorption, and stability were further investigated. The results showed that puerarin and silybin formed a co-amorphous system at a single glass transition temperature which was higher than that of any crude drug. The intrinsic dissolution rate and supersaturated powder dissolution of silybin in the co-amorphous system were higher than those of the crude drug and amorphous system. The co-amorphous system kept stable for as long as three months under the condition of 40 ℃, 75% relative humidity, which was longer than that of the single amorphous silybin. Therefore, the co-amorphous technology could significantly improve the dissolution and stability of silybin.

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.

Study on preparation extraction process of Linggui Zhugan Decoction / 中国中药杂志

To verify the appropriate preparation process of extracts for the solid substance benchmark of Linggui Zhugan Decoction. The extracts were prepared by different preparation processes, namely the traditional process(process 1), the extract combined with volatile oil separated from traditional process extract liquid(process 2), the modern secondary reflux extraction process(process 3) and the process that volatile oil was extracted first, then prepared according to the traditional process, and combined with extract(process 4); based on the characteristic spectrum, index components of cinnamaldehyde, glycyrrhizin, ammonium glycyrrhizinate, cinnamic acid, and the dry extract rate of process 1, the differences and similarities of four extracts were compared. The results showed that the similarity of the characteristic spectrum of process 2, process 4 and process 1 were all greater than 0.97, while there was no significant difference for the content of 4 quality control components and dry extract rate; the similarity of the characteristic spectrum of process 3 and process 1 was 0.91, the absolute peak area of 13 out of 21 peaks and the relative peak area of 7 peaks increased significantly, and the content of 3 out of 4 quality control components and dry extract rate also significantly increased. In conclusion, the material standards of extracts by the process 2 and 4 are consistent with that of the traditional process, so the two processes are suitable.

Prevention and control of HIV/AIDS in China: lessons from the past three decades / 中华医学杂志(英文版)

In the past 37 years, human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) has undergone various major transmission routes in China, with the world most complex co-circulating HIV-1 subtypes, even the prevalence is still low. In response to the first epidemic outbreak of HIV in injecting drug users and the second one by illegal commercial blood collection, China issued the Anti-Drug Law and launched the Blood Donation Act and nationwide nucleic acid testing, which has avoided 98,232 to 211,200 estimated infections and almost ended the blood product-related infection. China has been providing free antiretroviral therapy (ART) since 2003, which covered >80% of the identified patients and achieved a viral suppression rate of 91%. To bend the curve of increasing the disease burden of HIV and finally end the epidemic, China should consider constraining HIV spread through sexual transmission, narrowing the gaps in identifying HIV cases, and the long-term effectiveness and safety of ART in the future.

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.

Effect of precipitation inhibitors on pH-induced supersaturated phase behavior of dl-tetrahydropalmatine / 中草药

Objective: To investigate the effect of three types of precipitation inhibitors (PPI) HPMC K4M, HPMC AS MG and Soluplus on the pH-induced supersaturated phase behavior of dl-tetrahydropalmatine (dl-THP) at oral clinical doses. Methods: dl-THP pH solubility phase diagram and desaturation curve during pH-shift were drawn, and the solubility phase diagram was used to support dl-THP phase behavior. Area under the concentration-time curve and supersaturation ratio were used to analyze the effect of PPI on the phase behavior of dl-THP; Polarized light microscope and differential scanning calorimetry were used to analyze the precipitation properties. Results: Under the clinical dosage, the maximum supersaturation of dl-THP during the pH-shift was 3.93, and the supersaturation was lost over time; HPMC K4M, HPMC AS MG, and Soluplus could all maintain the supersaturation within 180 minutes during the pH-shift dissolution. HPMC K4M, HPMC AS MG, and Soluplus maintained supersaturation levels of 1.19, 1.89 and 1.36 respectively at a concentration of 5%, 1.30, 2.35 and 1.86 at a concentration of 20%, and 1.30, 2.60 and 2.07 at a concentration of 50%. Polarized light microscopy and differential scanning calorimetry results showed that crystalline precipitation occurred. Conclusion: All precipitation inhibitors can improve the pH-induced supersaturated phase behavior of tetrahydropalmatine, and this improvement behavior varies with the type and concentration of precipitation inhibitors. HPMC AS MG has the best effect.

Preparation and in vitro quality evaluation of curcumin supersaturated self-nanoemulsion / 中国中药杂志

In order to improve the supersaturation and maintenance time of drug dispersion in curcumin self-nanoemulsion(CUR-SNEDDS), precipitation inhibitors(PPIs) were introduced to prepare curcumin supersaturated self-emulsion(CUR-SSNEDDS). The composition of CUR-SNEDDS prescriptions was selected through the solubility test, the compatibility of oil phase and surfactant, the investigation of the emulsifying ability of the surfactant and the drawing of the pseudo-ternary phase diagram. Analytic hierarchy process was used in combination with central composite design-response surface method to optimize the prescription. The type and dosage of precipitation inhibitors(PPIs) were selected to maintain the supersaturated concentration and duration of CUR in artificial gastrointestinal fluids. At the same time, polarizing microscope was used to evaluate the crystallization inhibition effect and the quality and in vitro release behavior of CUR-SSNEDDS. The prepared CUR-SSNEDDS prescription was capryol 90-kolliphor RH40-transcutol HP-Soluplus(7.93∶66.71∶25.36∶5), with the drug loading of(65.12±1.25) mg·g~(-1). CUR-SSNEDDS was transparent yellow, and the nanoemulsion droplets were spherical with uniform distribution. The emulsification time was(21.02±0.13) s, the average particle size was(57.03±0.35) nm, the polydispersity index(PDI) was(0.23 ± 0.01), and the Zeta potential was(-18.10±1.30) mV. CUR-SSNEDDS significantly inhibited the generation and growth of crystals after in vitro dilution. The supersaturation could be maintained above 10 within 2 h, and the dissolution rate and degree of CUR in artificial gastrointestinal fluid were significantly increased. Soluplus could effectively maintain the supersaturated state of CUR and enhance CUR dissolution in vitro.