The swelling behavior of choline fenofibrate hydrogel matrix tablets using dynamic image analysis / 药学学报

The purpose of this study is to investigate the effects of formulation on the swelling behavior of choline fenofibrate hydrogel matrix tablets and reveal the relation between swelling property and release profile using dynamic image analysis. The volume swelling ratio (SR) and height/width (k) could evaluate the swelling behavior of matrix tablets well. The mount of hydroxypropyl methylcellulose (HPMC) and the ratio between K15M and K4M affected the volume swelling ratio, while PVP didn't. The three factors all impacted k, which was an indicator of the strength of the gel formed by HPMC. The accumulative release ratio and SR, the rate of swelling and the rate of release were compared. The proper model equations were established for the results with an excellent correlation. The results prove that there is a strong relevance between the swelling behavior and release property. This study provides a guideline in the study design for hydrogel matrix tablets.

Preparation and properties of thermosensitive in situ gel for ophthalmic formulation containing pearl hydrolyzate / 药学学报

The study was designed to generate an ophthalmic thermosensitive in situ gel with improved mechanical and mucoadhesive properties that may prolong the retention time to enhance the bioavalability of pearl hydrolyzate. The gene was comprised of poloxamer 407, poloxamer188 and Carbopol 934, which were optimized by central composite design and response surface methodology. The rheological properties, transcorneal permeability, retention time and in vitro release behaviors of the optimal gel formulation were investigated. The gel was Newtonian liquid at 25℃ and performed as a semisolid gel with non-Newtonian liquid property with a gelation time of 13 s at 35℃. Compared with a conventional eye drops, the ophthalmic in situ gel exhibited a sevenfold increase in retention with a sustained release behavior, which was observed with suitable permeability coefficient at 5.58 cm·s-1. In conclusion, the new gel of pearl hydrolyzate prolonged the release duration of drug, which may decrease the frequency of administration of pearl hydrolyzate. kilometers with ecological similarity between 20% and 40%, mainly in Yunnan, Guangxi, Guangdong, Guizhou, Hainan, Sichuan, Fujian and Chongqing. The climate factors mainly affecting the distribution of Panax notoginseng (Burk.) F. H. Chen were precipitation of warmest quarter, SD of temperature seasonality, altitude, isothermality, coefficient of variation of precipitation seasonality, mean temperature of monthly, precipitation of driest month, reference bulk density of soil and soil texture.

Isoflavonoids from Caragana changduensis and their nitric oxideinhibitory activities / 中国中药杂志

Ten isoflavonoids were isolated from the heartwoods of Caragana changduensis Lion f. by means of various column chromatographic techniques. Based on the detailed spectral data analysis (MS and NMR), as well as comparison with the literatures, their chemical structures were determined as 7,2'-dihydroxy-8,4'-dimethoxyisoflavone (1), 4'-hydroxy-7,3'-dimethoxyisoflavone (2), 5, 7, 4'-trihydroxy-2',5'-dimethoxyisoflavone (3), prunetin (4), afrormosin (5), odoratin (6), genistein (7), texasin (8), pratensein (9), and 6,7,3'-trihydroxy-4'-methoxyisoflavone (10). Among them, compounds 1-3 and 9-10 were isolated from the Caragana genus for the first time. All the compounds were obtained from this species for the first time. In the preliminary assays, compounds 1, 2, 6, and 7 possessed significant inhibitory effects on NO production, with IC50 values of 48.12, 25.32, 62.71, 43.59 μmol x L(-1), respectively.

Determination of contact angle of pharmaceutical excipients and regulating effect of surfactants on their wettability / 药学学报

To study the effects of surfactants on wettability of excipients, the contact angles of six types of surfactants on the surface of two common excipients and mixture of three surfactants with excipients were measured using hypsometry method. The results demonstrated that contact angle of water on the surface of excipients was associated with hydrophilcity of excipients. Contact angle was lowered with increase in hydrophilic groups of excipient molecules. The sequence of contact angle from small to large was starch < sodium benzoate < polyvinylpyrrolidone < sodium carboxymethylcellulose < sodium alginate < chitosan < hydroxypropyl methyl cellulose <magnesium stearate. In addition, surfactants both in droplets and mixed in excipients significantly reduced the contact angle of excipients, and their abilities to lower contact angle varied. The results of the present study offer a guideline in the formulation design of tablets.

A high-performance liquid chromatography with circular dichroism detector for determination of stereochemistry of 6, 9-oxygen bridge dibenzocyclooctadiene lignans from kadsura coccinea / 中国天然药物

The stereochemistry of two 6, 9-oxygen bridge dibenzocyclooctadiene lignans from Kadsura coccinea, are difficult to separate and very unstable. The present study was designed to develop a high-performance liquid chromatography using circular dichroism detection for the analysis of the stereochemistry. A new 6, 9-oxygen bridge dibenzocyclooctadiene lignans named Kadsulignan Q was firstly found with an S-biphenyl configuration. The other compound was identified as Kadsulignan L with an R- biphenyl configuration. In order to obtain kinetic data on their reversible interconversion, the stability was measured at different deuterated solvents such as deuterated methanol, deuterated chloroform and deuterated dimethylsulfoxide. The lignans were more unstable and converted more easily in deuterated methanol than in deuterated chloroform and deuterated dimethylsulfoxide.

Effects of ultrahigh pressure extraction on yield and antioxidant activity of chlorogenic acid and cynaroside extracted from flower buds of Lonicera japonica / 中国天然药物

The present study was designed to establish and optimize a new method for extracting chlorogenic acid and cynaroside from Lonicera japonica Thunb. through orthogonal experimental designl. A new ultrahigh pressure extraction (UPE) technology was applied to extract chlorogenic acid and cynaroside from L. japonica. The influential factors, including solvent type, ethanol concentration, extraction pressure, time, and temperature, and the solid/liquid ratio, have been studied to optimize the extraction process. The optimal conditions for the UPE were developed by quantitative analysis of the extraction products by HPLC-DAD in comparison with standard samples. In addition, the microstructures of the medicinal materials before and after extraction were studied by scanning electron microscopy (SEM). Furthermore, the extraction efficiency of different extraction methods and the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of the extracts were investigated. The optimal conditions for extracting chlorogenic acid and cynaroside were as follows: ethanol concentration, 60%; extraction pressure, 400 MPa; extraction time, 2 min; extraction temperature, 30 °C; and the solid/liquid ratio, 1 : 50. Under these conditions, the yields of chlorogenic acid and cynaroside were raised to 4.863% and 0.080%, respectively. Compared with other extraction methods, such as heat reflux extraction (HRE), ultrasonic extraction (UE), and Sohxlet extraction (SE), the UPE method showed several advantages, including higher extraction yield, shorter extraction time, lower energy consumption, and higher purity of the extracts. This study could help better utilize L. japonica flower buds as a readily accessible source of natural antioxidants in food and pharmaceutical industries.

The rheology properties of common hydrophilic gel excipients / 药学学报

To investigate theological properties of common hydrophilic gel excipients such as Carbopol based on viscosity, the viscosity was determined by rotation method and falling-ball method. Linear regression was made between ln(eta) and concentration, the slope of which was used to explore the relation between viscosity and concentration of different excipients. The viscosity flow active energy (E(eta)) was calculated according to Arrhenius equation and was used to investigate the relation between viscosity and temperature of different excipients. The results showed that viscosities measured by two methods were consistent. Concentration of guargum (GG) and hydroxypropylmethyl cellulose (HPMC) solution had a great influence on the viscosity, k > 5; while concentration of polyvinylpyrrolidone-K30 (PVP-K30) and polyethylene glycol 6000 (PEG6000) exerted a less effect on viscosity, k < 0.2; viscosity flow active energy of different excipients were close, which ranged from 30 to 40 kJ x mol(-1). Therefore, theological properties study could provide the basis for application of excipients and establish a foundation for the research of relation between excipients structure, property and function.