ABSTRACT
Hygrophila salicifolia is an erect herb (family: Acanthaceae). It has many medicinal uses like diuretic and anti inflammatory in traditional systems of medicine. Till date no data available for its standardisation therefore isolation of phytoconstituent was done from methanolic extract of Hygrophila salicifolia. Besides a known flavonoid, Isoquercitrin was isolated for the first time from a Hygrophila species, namely Hygrophila salicifolia (Acanthaceae). Its structure was established on the basis of its spectroscopic data.
ABSTRACT
OBJECTIVE: To evaluate the equivalence among three different methods for drug melting point determination:①method A1 by glass liquid thermometer, ②method A2 by digital display,and ③ method B by instrumental method. METHODS: Five chemical reference substances with different melting points were selected as the target drugs, and different brands of melting point apparatus were used to determine melting point. The apparatus used by method A consists of a glass container for a liquid bath and fitted with a suitable means of heating.The obtained results of the melting point by method A1, A2 and B were evaluated by equivalence testing referring to the data of Proficiency Testing Scheme for the melting point determination of chemical drugs organized by NIFDC in 2015 and 2016. RESULTS: Method A1, A2 and B were equivalent,and no significant difference were observed for the melting point values determined by the three methods. CONCLUSION: There is no significant difference between the melting point determination method A and method B in the Chinese Pharmacopoeia(Ch.P), and the obtained melting point values are equivalent either by glass liquid thermometer or digital display while using method A. This experiment provides scientific data support for potential adoption of digital display in melting point apparatus by Ch.P.
ABSTRACT
Objective:To determine the phase-transition temperature of white vaseline produced by different processes by differen-tial scanning calorimetry ( DSC) in order to analyze the relevance between the melting point and the phase-transition temperature and the relevance between different production processes and the phase-transition temperature. Methods: Hermertic aluminum pans were used to encapsulate the samples, and the testing conditions were optimized. The sample weight was about 10 mg, and the range of measuring temperature was -20-100℃. The heating rate was 5℃·min-1 and the flow rate of nitrogen was 30 ml·min-1 . Results:The phase-transition temperature and the melting point were significantly different. The phase-transition temperature of white vaseline samples produced by different processes was quite different. Conclusion:Melting point determination in the current standard method of white vaseline exists defects, and the composition of white vaseline produced by various processes is quite different.
ABSTRACT
Here, we examined the effect of melting point of drug carriers on drug release of dexamethasone (Dex)-loaded microspheres. We prepared poly(L-lactide-ran-ε-caprolactone) (PLC) copolymers with varying compositions of poly(εcaprolactone) (PCL) and poly(L-lactide) (PLLA). As the PLLA content increased, the melting points of PLC copolymers decreased from 61 to 43 ℃. PLC copolymers in vials solubilized at 40–50 ℃ according to the incorporation of PLLA into the PCL segment. Dexamethasone (Dex)-loaded PLC (MCxLy) microspheres were prepared by the oil-in-water (O/W) solvent evaporation/extraction method. The preparation yields were above 70%, and the mean particle size ranged from 30 to 90 µm. The MC(x)L(y) microspheres also showed controllable melting points in the range of 40–60 ℃. Dex-loaded MC(x)L(y) microspheres showed similar in vitro and in vivo sustained release patterns after the initial burst of Dex. The in vitro and in vivo order of the Dex release was MC₈₀L₂₀>MC₉₀L₁₀>MC₉₅L₅, which agreed well with the melting point order of the drug carrier. Using in vivo fluorescence imaging of fluorescein (FI)-loaded microspheres implanted in animals, we confirmed the sustained release of FI over an extended period. In vivo inflammation associated with the PLC microsphere implants was less pronounced than that associated with Poly(lactide-co-glycolide) (PLGA). In conclusion, we successfully demonstrated that it is possible to control Dex release using Dex-loaded MC(x)L(y) microspheres with different melting points.
Subject(s)
Animals , Dexamethasone , Drug Carriers , Drug Liberation , Fluorescein , Freezing , In Vitro Techniques , Inflammation , Methods , Microspheres , Optical Imaging , Particle Size , Polyglactin 910ABSTRACT
Objective:To evaluate the capacity and level of melting point determination of chemical drugs in the laboratories par-ticipating in the proficiency testing. Methods:Two test samples were prepared, and the labs volunteered to participate in the proficien-cy testing program ( PTP) . The melting point determination was performed according to the general principle 0612 in part four of Chi-nese Pharmacopoeia (2015 edition), and the results were analyzed by robust statistics and the determination proficiency of the laborato-ries were evaluated by Z-score. Results:The analysis showed that two test samples were homogeneous and stable, which met the re-quirements of the PTP. Totally 31 laboratories had satisfactory results, which accounted for 83. 8%. Conclusion:The majority of the participant laboratories can accurately determine the melting points of test samples, and the information is very helpful to the next profi-ciency testing program.
ABSTRACT
OBJECTIVE: To identify a suitable polymer system for iguratimod (T-614), a poorly water-soluble compound with high melting point, and prepare a chemically stable single phase solid dispersion (SD) of T-614 by hot-melt extrusion (HME) technique to enhance its dissolution rate. METHODS: Melting method and adsorption based screening techniques were utilized to screen hydrophilic polymers suitable for immediate release formulations. T-614 SDs were prepared with polymer carriers such as PVP/VA 64, Soluplus, HPMC AS-LF and HPC-SL via HME below the drug melting point, and suitable temperature and plasticizer for HME were chosen. The dissolution behaviors of SD powder and SD tablets were compared with those of T-614 powder and commercial T-614 tablets, respectively. State of T-614 in HME SDs was characterized by X-ray powder diffraction. The homogenous SD tablets were analyzed further for physical stability in an influencing factors test. The bioavailability of SD tablets was assessed in rats. RESULTS: Results of the screening studies demonstrated that PVP/VA 64, Soluplus, HPMC AS-LF and HPC-SL provided higher degree of miscibility and dissolution enhancement. The HWE SD tablets showed significantly enhanced dissolution. The supersaturation state of HME SD powder in water was maintained for at least 120 min, suggesting that PVP/VA 64 had an inhibitory effect on recrystallization of T-614 from a supersaturated solution. Samples prepared via HME at 160°C were substantially amorphous, which were unchanged in the influencing factors test at high temperature and strong light, but recrystallization occurred at high humidity. PEG1500 appeared to be a promising plasticizer. Same bioavailability was achieved when compared with commercial T-614 tablets. CONCLUSION: The polymersas carriers for T-614 SD have significant impact on the dissolution behavior and state of T-614. Using PVP/VA 64 as the carrier, hot-melt extrusion is an effective technology for improving the in vitro dissolution of T-614.
ABSTRACT
BackgroundThe preparations of multi-component have been the subject of chemical study for a long time. Therefore, when compounding the preparations of multi-component in traditional medicine, their taste is cautiously relied on, as the power of the one medicine should not be subdued with the power of another. Additionally the properties of the components and their regulating effects on the body systems are also considered. Our research group has been carrying out tests for raw materials,which are contained in multi-component preparations. However, it is a necessity to conduct phytochemical study on multi-component preparations in order to isolate pure biological active compounds and to identify their structure as well as to quantify its amount by modern techniques of analysis.GoalThe aim of the present study was to isolate pure biological active substances from Mongolian traditional medicine Garidi-5 and to elucidate their structures, which was used in Mongolian traditional medicine for the treatment of inflammation and as a pain relieving remedy.Objectives:1. To isolate pure substances from Garidi-5 and carry out tests to identify and determine their structure2. To quantify the amount of biological active substances.Materials and MethodsMongolian traditional medicine Garidi-5 has been selected as a biological natural product for the study. Garidi-5 is a traditional Mongolian medicine consisting of 5 medicinal herbs, namely Terminalia chebula Retz., Aconitum Kusnezoffii Reichb., Acorus calamus L., Saussurea lappa L., and musk of Moschus moschiferus and manufactured in the Drug factory of Traditional Medical Science Technology and Production Corporation of Mongolia. In this research, in order to determine the total content of phenolic compound was used the Folin–Ciocalteu method, which based on performing dark blue color complex compound. Isolated substance identification was determined by the TLC, UV and IR spectrophotometric methods. Inaddition it was checked melting point of the isolated substance. Determination of Gallic acid30g Garidi-5 was macerated in 60ml 80% methanol at room temperature for 24 h. After extraction, the extract was concentrated and vacuum evaporated. Different solvents from hexane, chloroform, ethyl acetate and n-butanol were used for theexperiment. All the extracts collected, evaporated and chromatographed on Silica gel column. Future purification of active fractions on Silica gel with methanol yielded the compound G1 which was further characterized as Gallic acid. Total phenolic content was determined spectrophotometrically according to the Folin–Ciocalteu’s method with slight modification. Gallic acid was used as a standard phenolic compound. Briefly, 1 ml of extract solution contains 1 mg extracts, in a volumetric flask diluted with distilled water (46 ml). One ml of Folin-Ciocalteu reagent was added and the content of the flask mixed thoroughly. After 3 min, 3 ml of Na2CO3 (2%) was added and then the mixture was allowed to stand for 2 h with intermittent shaking. The absorbance was measured at 760 nm in a spectrophotometer. All measurements were performed in triplicate.ResultsIn this research, TLC method on silica gel plates was used in order to identify the biological active pure substances from Garidi-5. Preliminary TLC experiments indicated the presence of Gallic acid in Garidi-5, which was isolated by column chromatography by comparing with reference standard substance (Gallic acid). Gallic acid was determined in the solvent system benzole-ethyl acetateformic acid- acetone (5:5:2:0.5) in isolated substance (G1). It showed blue color, Rf =0.65, on TLC plate. [1] For the characterization of two samples it was carried out IR analysis for each. In the IR spectra of G1 and standard substance can be recognized by the following absorption frequency regions: 700-900 cm-1 for Car-H; 1000-1300 cm-1 for vibration of bonds in various oxygen containing groups, 1350-1470 cm-1 for vibrations of –CH, -CH2 and –CH3 groups; 1500-1630 cm-1 for skeletal vibrations of aromatic rings, >C=O bonds; 2800-2950 cm-1 for stretching vibrations of –CH, -CH2 and -CH3 groups in saturated aliphatic structures; and 3030-3350 cm-1 for stretching associated vibrations of -OH groups in aromatic rings and aliphatic structures. As a result it was revealed that both IR spectra of G1 and standard substances were similar. [3]Further for the characterization of two samples it was carried out UV analysis of each. In the UV spectra of G1 and standard substance can be recognized by the following absorption frequency regions: 260-280nm for benzole groups; 200-225nm for carbonic acids; 400-770nm >C=O bonds, which reveal the presence of Gallic acid. In addition, melting point of isolated substance G1 was analyzed and detected at 2410C, which was similar to the standard substance’s melting point. [4]Moreover, Mongolian traditional medicine Garidi-5 contains 24% of the biological active substance (total phenolic compounds). [2]Conclusions:As a result of current study on Mongolian medicine Garidi-5, it was isolated one essential substance from ethyl acetate fraction. The phytochemical analysis reveals the presence of Gallic acid in Garidi- 5, which was determined by thin layer chromatography, UV and IR spectrophotometric methods. Mongolian traditional medicine Garidi-5 contains 24% of the biological active substance. Thus, the isolation of Gallic acid from multi-component preparations and identification of its structure was first phytochemical study conducted in our laboratory.
ABSTRACT
Objective To compare the dosimetric difference between the two beams formed by low melting-point lead (LML) and multileaf collimator (MLC) in orbit radiotherapy, so as to select the one with a lower lens dose for treatment of Graves' ophthalmopathy. Methods Patients with unilateral and bilateral Graves' ophthalmopathy (10 cases each) suitable for radiotherapy were selected for dosimetric comparison. The identical sketching principle of target volume was employed, and the prescribed dose of planning target volume (PTV) was 2000 cGy/10 times. The distribution of radiation field in unilateral group was 3 fields (2 X-ray fields + 1 electron field), and in bilateral group was 4 fields (2 X-ray fields + 2 electron fields), and LML and MLC were employed to form the radiation field. The conformity index (CI) and dose volume histogram (DVH) were compared between the two formation methods of radiation field; the effective penumbra area of the half radiation field formed by the two methods and its influence on the lens dose were analyzed with flushing-free film and dose analysis software. Results The average dose of the affected side lens in MLC unilateral group was 582 ± 34cGy, and of the lens of uninjured side was 160 ± 22cGy, the CI of target volume was 0.69; the average dose of the left and right lens in MLC bilateral group was 591 ± 47cGy and 585 ± 52cGy, respectively, and the CI was 0.67. The average dose of the affected side lens in LML unilateral group was 252 ± 45cGy, and that of the uninjured side lens was 148 ± 19cGy, and the CI was 0.71; the average dose of the left and right lens in LML bilateral group was 247 ± 44cGy and 256 ± 42cGy, respectively, and the CI was 0.68. When the X-ray energy was setup at 4MV and 8MV, the half radiation field was 5cm X 5cm with a depth of 4cm, and the effective penumbra area of LML was 3mm smaller than that of MLC. Conclusion A small radiation area formed by LML may be more appropriate, and it may not only diminish the penumbra of radiation field, also it significantly reduce the irradiation dose imparted to patients' affected side lens.
ABSTRACT
OBJECTIVE: To study the physical and chemical properties and transdermal delivery characteristics oi capsaicin. METHODS: Equilibrium solubility method, ultraviolet spectrophotometry, bottle-shaking method, differential scanning ealorimetry (DSC) and in vitro diffusion cell method were used to determine the apparent solubility, dissociation constant, apparent oil/water partition coefficient, melting point and percutaneous penetration of capsaicin, respectively. And the permeation characteristics were evaluated by lag time method. RESULTS: Capsaicin was slightly dissolved in water, and the apparent solubility was (22.85 ± 0.06) mg · L-1. It was a weak base with a dissociation constant of (10.25 ± 0.11). The apparent oil/water partition coefficient of capsaicin changed with the pH value, and increased when pH was greater than 8. Its melting point was 60.20°C. The residence time(ttag) was (2.437 ± 0.273) h, the permeability coefficient (P) (7.012 ± 0.341) × 10-2cm · h-1, and the percutaneous penetration rate (Js) (4.647 ± 0.226) μg · cm-2 · h-1. CONCLUSION: Capsaicin possesses appropriate physical and chemical properties for percutaneous penetration and exhibits excellent percutaneous penetration.
ABSTRACT
Besides a known Coumarin derivative, Scopoletin, the iridoids gardenoside was isolated for the first time from an Ipomoea species, namely Ipomoea reniformis (Convolvulaceae). Its structure was established on the basis of its spectroscopic data.
ABSTRACT
Objective Rheological properties and gelation properties of agar were investigated. Methods The gelling point,melting point and the gel strength of agar were detected with MCR101 rheometer and TA texture testing instrument. Results and Conclusion Rheological properties of agar were affected by its concentration ,temperature and the addition of salt (such as NaCl ,CaCl2) and sucrose. Apparent viscosity exhibited shear thinning behavior following the power law model. Apparent viscosity increased with the increase of concentration,and decreased with the rise of temperature. The decrease in viscosity followed an Arrhenius temperature dependence. Agar solutions exhibited typical "weak gel" properties by small strain oscillatory measurements. The results indicated that the agar solution was characterized as a gel properties ,and which could form a kind of heat reversible gel. The gelling point of agar was lower than its melting point. The gel strength of agar could be affected by its gel time,and the addition of salt (such as NaCl,CaCl2) and sucrose.