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.
Calorimetry, Differential Scanning ; Desiccation ; Drug Compounding/methods* ; Drug Stability ; Silybin ; Solubility ; Spectroscopy, Fourier Transform Infrared ; Technology ; X-Ray Diffraction

This study was designed to explore the potential of gypenosides as a novel natural stabilizer for the production of nanosuspensions. The gypenosides-stabilized quercetin nanosuspensions(QUE-NS) were prepared using the high-speed shearing and high-pressure homogenization method with quercetin as a model drug, followed by their in vitro evaluation.Based on the measured mean particle size and polydispersity index(PDI) of QUE-NS,the single factor experiment was conducted to optimize the preparation process parameters.The freeze-drying method was used to transform QUE-NS into freeze-dried powders, whose storage stability and saturation solubility were then studied.Moreover, the effects of pH and ionic strength on the physical stability of the nanosuspension system were examined.According to the results, the optimized process parameters were listed as follows: shear rate 13 000 r·min~(-1),shear time 2 min, homogenization pressure 100 MPa, and homogenization frequency 12 times.The mean particle size of QUE-NS prepared under the optimum process conditions was(461.9±2.4) nm, and the PDI was 0.059±0.016.During the two months of storage at room temperature, the freeze-dried QUE-NS powders remained stable.The saturation solubility of freeze-dried QUE-NS powders was proved higher than those of quercetin and the physical mixture.The results of stability testing demonstrated that QUE-NS stabilized with gypenosides exhibited good stability within the pH range of 6 to 8,while coalescence was prone to occur in the presence of salt.Overall, gypenosides is expected to become a new natural stabilizer for the preparation of nanosuspensions.
Drug Stability ; Gynostemma ; Nanoparticles ; Particle Size ; Plant Extracts ; Powders ; Quercetin ; Solubility ; Suspensions

To enhance in vitro dissolution of Cur by preparing Cur solid dispersions. The ability of HPMCAS-HF,HPMCAS-MF,HPMCAS-LF and PVPK30 to maintain supersaturated solution was investigated by supersaturation test. Amorphous solid dispersions were prepared by the solvent-evaporation method. The prepared samples were characterized using infrared spectroscopy( IR) and differential scanning calorimetry( DSC),and in vitro dissolution was investigated. DSC and IR results showed that in 1 ∶3 and 1 ∶9 solid dispersions,Cur was amorphously dispersed in the carrier,and the interaction existed between drug and carrier. The supersaturation test showed that the order of the ability of polymer to inhibit crystallization of Cur was MF>HF>LF>K30. The dissolution results showed that Cur-K30 amorphous solid dispersion had the highest drug release rate; Cur-K30 and Cur-LF amorphous solid dispersions had a quicker but not stable dissolution rate,and the drug concentration decrease after 4 h; Cur-MF and Cur-HF solid dispersions had a low dissolution,which however increased steadily,attributing to the strong ability of the polymers to inhibit the crystallization of Cur. HPMCAS could inhibit the degradation of Cur better than K30,especially MF and HF. The amorphous solid dispersions of cur significantly enhanced the dissolution of Cur and improved the chemical stability of Cur. This study can provide a basis for the rational selection of the polymer used for Cur solid dispersion.
Chemistry, Pharmaceutical ; Curcumin ; chemistry ; Drug Stability ; Methylcellulose ; analogs & derivatives ; chemistry ; Polymers ; Solubility

β-Carotene is one of the most abundant natural pigments in foods; however, usage of β-carotene is limited because of its instability. Microencapsulation techniques are usually applied to protect microencapsulated β-carotene from oxidization. In this study, β-carotene was microencapsulated using different drying processes: spray-drying, spray freeze-drying, coating, and spray granulation. The properties of morphology, particle size, water content, thermal characteristic, and chemical stability have been explored and compared. Scanning electron microscopy measurements showed that the coated powder had a dense surface surrounded by starch and suggested that the coating process gave a microencapsulated powder with the smallest bulk density and the best compressibility among the prepared powders. The chemical stabilities of microcapsules were evaluated during six months of storage at different temperatures. The coated powder had the highest mass fraction of β-carotene, which indicated that the coating process was superior to the three other drying processes.
Drug Compounding/methods* ; Drug Stability ; Freeze Drying ; Microscopy, Electron, Scanning ; Technology, Pharmaceutical ; beta Carotene/chemistry*

The present study was designed to improve storage stability and oral bioavailability of Ganneng dropping pills (GNDP) by transforming lignans of Herpetospermum caudigerum (HL) composed of herpetrione (HPE) and herpetin (HPN) into nanosuspension (HL-NS), the main active ingredient of GNDP, HL-NS was prepared by high pressure homogenization and lyophilized to transform into solid nanoparticles (HL nanoparticles), and then the formulated HL nanoparticles were perfused into matrix to obtain NS-GNDP by melting method. For a period of 3 months, the content uniformity, storage stability and pharmacokinetics test in vivo of NS-GNDP were evaluated and compared with regular GNDP at room temperature. The results demonstrated that uniformity of dosage units of NS-GNDP was acceptable according to the criteria of Chinese Pharmacopoeia 2015J. Physical stability of NS-GNDP was investigated systemically using photon correlation spectroscopy (PCS), zeta potential measurement, and scanning electron microscopy (SEM). There was a slight increase in particles and PI of HL-NS re-dispersed from NS-GNDP after storage for 3 months, compared with new formulated NS-GNDP, which indicated a good redispersibility of the NS-GNDP containing HL-NS after storage. Besides, chemical stability of NS-GNDP was studied and the results revealed that HPE and HPN degradation was less when compared with that of GNDP, providing more than 99% of drug residue after storage for 3 months. In the dissolution test in vitro, NS-GNDP remarkably exhibited an increased dissolution velocity compared with GNDP and no distinct dissolution difference existed within 3 months. The pharmacokinetic study showed that HPE and HPN in NS-GNDP exhibited a significant increase in AUC, C and decrease in T when compared with regular GNDP. These results indicated that NS-GNDP possessed superiority with improved storage stability and increased dissolution rate and oral bioavailability.
Animals ; Benzofurans ; chemistry ; Biological Availability ; Cucurbitaceae ; chemistry ; Drug Carriers ; chemistry ; Drug Compounding ; Drug Stability ; Freeze Drying ; Furans ; chemistry ; Humans ; Lignans ; administration & dosage ; chemistry ; isolation & purification ; pharmacokinetics ; Male ; Nanoparticles ; administration & dosage ; chemistry ; Particle Size ; Plant Extracts ; chemistry ; isolation & purification ; Rats ; Rats, Sprague-Dawley ; Solubility

Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson's disease (PD), respectively, which manifested with the selective vulnerability of neuronal cells in substantia nigra (SN) and striatum (STR) regions. However, the underlying molecular mechanism linking parkin with the etiology of PD remains elusive. Here we report that p62, a critical regulator for protein quality control, inclusion body formation, selective autophagy and diverse signaling pathways, is a new substrate of parkin. P62 levels were increased in the SN and STR regions, but not in other brain regions in parkin knockout mice. Parkin directly interacts with and ubiquitinates p62 at the K13 to promote proteasomal degradation of p62 even in the absence of ATG5. Pathogenic mutations, knockdown of parkin or mutation of p62 at K13 prevented the degradation of p62. We further showed that parkin deficiency mice have pronounced loss of tyrosine hydroxylase positive neurons and have worse performance in motor test when treated with 6-hydroxydopamine hydrochloride in aged mice. These results suggest that, in addition to their critical role in regulating autophagy, p62 are subjected to parkin mediated proteasomal degradation and implicate that the dysregulation of parkin/p62 axis may involve in the selective vulnerability of neuronal cells during the onset of PD pathogenesis.
Adaptor Proteins, Signal Transducing ; chemistry ; metabolism ; Animals ; HEK293 Cells ; Heat-Shock Proteins ; chemistry ; metabolism ; Humans ; Lysine ; metabolism ; Mice ; Neurons ; metabolism ; pathology ; Oxidopamine ; pharmacology ; Parkinson Disease ; metabolism ; pathology ; Proteasome Endopeptidase Complex ; metabolism ; Protein Stability ; Proteolysis ; drug effects ; Sequestosome-1 Protein ; Ubiquitin-Protein Ligases ; metabolism ; Ubiquitination ; drug effects

OBJECTIVETo develop a reliable method to assess the stability of xinyue capsules containing Panax quinquefolius saponins according to European quality standards.

METHODSAn efficient high-performance liquid chromatography ultraviolet (HPLC-UV) method was established to analyse six main ginsenosides (Rb1, Rb2, Rc, Rd, Re and Rg1) in six different batches (120 capsules/batch) from the same lot of xinyue capsules and in one batch measured six times within one day. The six ginsenosides were separated on a Hypersil BDS-C18 column (3 μm, 100 mm×3 mm) at a flow rate of 0.5 mL/min. Gradient elution was performed using a mobile phase gradient of acetonitrile-water modified with 0.01% formic acid. The HPLC chromatograms were analyzed with "LC data comparison" using Lab Solutions software.

RESULTSThe HPLC peaks were identified by comparing their retention times (Rg1: 23.44 min, Re: 23.77 min, Rb1: 35.24 min, Rc: 36.18 min, Rb2: 38.55 min and Rd: 40.88 min) with those of the standards under the same chromatographic conditions, which showed similar results among the samples of six different batches and among the samples from one batch detected six times within one day.

CONCLUSIONSXinyue capsules have good drug intra-day consistency at room temperature and exhibit a consistent quality between different batches. This study established a reliable method to assess the stability of xinyue capsules, which is suitable for further qualitative analysis and may assist in promoting the safe and effective use of Chinese herbal medicine.

1,3,5-Trimethylbenzene (1,3,5-TMB) was used as the pore-enlarging modifier to expand the pore size of MCM-41 (mobil company of matter) mesoporous silica nanoparticles. The solvent impregnation method was adopted to assemble non-water-soluble β-carotene into the pore channel of MCM-41. The MCM-41 and drug assemblies were characterized by TEM, FT-IR, elemental analysis and N2 adsorption-desorption. The results showed that MCM-41 has good sphericity and regular pore structure. The research also investigated the optimal loading time, the drug loading and the vitro stability of the β-carotene. As a drug carrier, the modified MCM-41 showing a shorter drug loading time, the drug loading as high as 85.58% and the stability of β-carotene in drug assemblies has improved. The study of this new formulation provides a new way for β-carotene application.
Drug Carriers ; chemistry ; Drug Delivery Systems ; Drug Stability ; Nanoparticles ; chemistry ; Silicon Dioxide ; chemistry ; beta Carotene ; chemistry ; pharmacology

Oleanolic acid-precipitated calcium carbonate solid dispersion was prepared by using solvent evaporation method. The microscopic structure and physicochemical properties of solid dispersion were analyzed using differential scanning calorimetry and scanning electron microscopy (SEM). And its in vitro release also was investigated. The properties of the precipitated calcium carbonate was studied which was as a carrier of oleanolic acid solid dispersion. Differential scanning calorimetry analysis suggested that oleanolic acid may be present in solid dispersion as amorphous substance. The in vitro release determination results of oleanolic acid-precipitated calcium carbonate (1: 5) solid dispersion showed accumulated dissolution rate of.oleanolic acid was up to 90% at 45 min. Accelerating experiment showed that content and in vitro dissolution of oleanolic acid solid dispersion did not change after storing over 6 months. The results indicated that in vitro dissolution of oleanolic acid was improved greatly by the solid dispersion with precipitated calcium carbonate as a carrier. The solid dispersion is a stabilizing system which has actual applied value.
Calcium Carbonate ; chemistry ; Calorimetry, Differential Scanning ; Chemistry, Pharmaceutical ; Drug Carriers ; chemistry ; Drug Stability ; Microscopy, Electron, Scanning ; Oleanolic Acid ; chemistry ; Plant Extracts ; chemistry ; Solubility

In order to solve the adhesion and the softening problems of traditional Chinese medicine extract during spray drying, a new method of adding dehumidified air into spray drying process was proposed, and the storage stability conditions of extract powder could be predicted. Kouyanqing extract was taken as model drug to investigate on the wet air (RH = 70%) and dry air conditions of spray drying. Under the dry air condition, the influence of the spray drying result with different air compression ratio and the spray-dried powder properties (extract powder recovery rate, adhesion percentage, water content, angle of repose, compression ratio, particle size and distribution) with 100, 110, 120, 130, 140 °C inlet temperature were studied. The hygroscopic investigation and Tg value with different moisture content of ideal powder were determined. The water activity-equilibrium moisture content (aw-EMC) and the equilibrium moisture content-Tg (EMC-Tg) relationships were fitted by GAB equation and Gordon-Taylor model respectively, and the state diagram of kouyanqing powder was obtained to guide the rational storage conditions. The study found that in the condition of dry air, the extract powder water content decreased with the increase of air compression ratio and the spray drying effect with air compression ratio of 100% was the best performance; in the condition of wet air, the extract powder with high water content and low yield, and the value were 4.26% and 16.73 °C, while, in the dry air condition the values were 2.43% and 24.86 °C with the same other instru- ment parameters. From the analysis of kouyanqing powder state diagram, in order to keep the stability, the critical water content of 3.42% and the critical water content of 0.188. As the water decreased Tg value of extract powder is the major problem of causing adhesion and softening during spray drying, it is meaningful to aid dehumidified air during the process.
Drug Stability ; Drugs, Chinese Herbal ; chemistry ; Humidity ; Medicine, Chinese Traditional ; Plant Extracts ; chemistry ; Powders ; Temperature