This study is to screen 23 blank O/W type microemulsion (ME) samples, that is 15 samples from our laboratory, and 8 samples from literature; compare the conductivity-water content curve (CWCC) method and visual method in determining the critical water content during O/W type MEs' formation, to analyze the deficiency and the feasibility of visual method and to exploxe scientific meanings of CWCC method in judging the critical water content of O/W type MEs during formation. The results show that there is a significant difference between the theoretical feasible CWCC method and visual method in determining the critical water content (P<0.001), and the results judged by conductivity is higher than that by eye-based water content. Therefore, this article firmly confirmed the shortcomings of visual method and suggested that the eye-base "critical water content" may falls into continuous ME stage during O/W MEs' formation. Further more, the CWCC method has theoretical feasibility and scientific meanings in determining the critical water content of O/W type MEs during formation.
Electric Conductivity ; Emulsions ; chemistry ; Water ; chemistry

To decrease the hemolysis side effect of puerarin, the basic formula and preparation of puerarin submicron emulsion were optimized and the physicochemical properties were evaluated. Puerarin submicron emulsions were prepared by phase inversion-ultrasound combining with phospholipids complexes technology. The effects of preparative parameters, such as emulsification time, stirring velocity and ultrasound time, on mean diameter, span of dispersity, entrapment efficiency and overall desirability were investigated. The three dimensional response surface graphs were produced by second-order polynomial and liner equation, which predict the optimal experiment conditions. All response variables were found to be greatly dependent on three independent variables. Second-order polynomial equations were fitter than liner equations for this study. The optimal emulsification time, stirring velocity and ultrasound time was 15 min, 2 000 r x min(-1), 30 min, respectively. The mean diameter, span of dispersity, entrapment efficiency, drug content and zeta potential of emulsions prepared by the method were 228.23 nm, 0.628 4, 84. 32%, 9.98 mg x mL(-1), - 29.03 mV, respectively. Puerarin submicron emulsion was prepared by the optimized preparation method. The narrow particle diameter distribution, high envelopment efficacy and good stability were obtained. The physicochemical properties were suitable for the requirement of the intravenous emulsion.
Emulsions ; Isoflavones ; administration & dosage ; chemistry ; Particle Size

OBJECTIVETo study the solubilization of O/W microemulsion system for volatile oil from Houttuynia Cordra and determine the formulation of its microemulsion.

METHODThe solubilization curve was drawn from pseudo-ternary phase diagram plotted by using the method of titration. The microemulsion's effect on solubilization for volatile oil from Houttuynia Cordra was systematically studied and the difference solubilization effects between colloid fluid and microemulsion were compared.

RESULTExcipient varieties and amount of microemulsion had effects on solubilization for volatile oil from Houttuynia Cordra. The formulation of its microemulsion was determined and we chose medium-chain triglycerides as oil phase, polyoxyethylene castor oil EL-35 as surfactant, propylene glycol as cosurfactant and the surfactant to cosurfactant ratio was 2.

CONCLUSIONSuitable microemulsion formulation can solubilize volatile oil from Houttuynia Cordra and it can provide research foundation for further development of microemulsion preparation for volatile oil from Houttuynia Cordra.

Emulsions ; chemistry ; Houttuynia ; chemistry ; Oils, Volatile ; chemistry ; Solubility

OBJECTIVETo prepare the oridonin submicron emulsion and characterize their properties.

METHODHigh pressure homogenization method was employed to prepare the oridonin submicron emulsion and such properties as size, Zeta potential and viscosity were characterized.

RESULTThe results showed that the submicron emulsions was formed with the drug loading 1 g L(-1), particle size of (138.87 +/- 0.60) nm, zeta potential of (47.27 +/- 2.31) mV, pH value of (6.02 +/- 0.03) and viscosity of (1.78 +/- 0.015) MPa s, respectively.

CONCLUSIONThe method is feasible and the submicron emulsions has stable properties. Experiments offer a new formulation of oridonin for clinical application.

Chemistry, Pharmaceutical ; Diterpenes, Kaurane ; chemistry ; Emulsions ; chemistry ; Particle Size ; Viscosity

A new quercetin nanocrystals self-stabilized Pickering emulsion(QT-NSSPE) was prepared by high-pressure homogenization combined with probe ultrasonic method. The influences of oil fraction, quercetin(QT) concentration, and pH of water phase on the formation of QT-NSSPE were investigated. On this basis, the QT-NSSPE prepared under optimal conditions was evaluated in terms of microstructure, stability, and in vitro release and the droplet size and drug loading were 15.82 μm and 4.87 mg·mL~(-1), respectively. The shell structure formed by quercetin nanocrystals(QT-NC) on the emulsion droplet surface was observed under a scanning electron microscope(SEM). X-ray diffraction(XRD) showed that the crystallinity of adsorbed QT-NC decreased significantly as compared with the raw QT. There were not significant changes of QT-NSSPE properties after 30 days of storage at room temperature. The in vitro release experiment confirmed that QT-NSSPE has a higher accumulative release rate than the raw QT. All these results indicated that QT-NSSPE has a great stability and a satisfactory in vitro release behavior, which is a promising new oral delivery system for QT.
Emulsions/chemistry* ; Nanoparticles ; Particle Size ; Quercetin ; Water/chemistry*

To improve mass transfer and enhance the yield for C(1,2) biodehydrogenation of steroid 11beta-hydroxyl medroxyprogesterone, we carried out the dehydrogenation reaction of 11beta-hydroxyl medroxyprogesterone in an oil-in-water (O/W) microemulsion by Arthrobacter simplex UR016. We studied the effects of system composition, dehydrogenation temperature and substrate concentration on microbial transformation. We formulated a suitable O/W microemulsion system with Arthrobacter simplex UR016 culture broth as aqueous phase, 10 g/L of edible oil as oil phase, 4 g/L of Tween-O80 and 7% (V/V) alcohol as surfactant and cosurfactant. The optimal dehydrogenation temperature was 33 degrees C. The results showed that in Tween-80/alcohol/edible oil/water microemulsion system, the hydrophobic steroid was solubilised and diffused effectively, with the maximum conversion rate of 88.6% at 46 h under 4 g/L substrate concentration, an increase of 66.2% compared to that in aqueous system. The C(1,2) biodehydrogenation of 11beta-hydroxyl medroxyprogesterone is more efficient in water-edible oil microemulsion system than in aqueous system.
Arthrobacter ; metabolism ; Biotransformation ; Emulsions ; Hydrogenation ; Medroxyprogesterone ; chemistry ; metabolism

OBJECTIVETo study the feasibility of digalactosyl diglyceride (DGDG) , which was used as a new type of emulsifier to prepare submicro-emulsion of bay oil.

METHODBay oil was employed as the model drug, emulsifer in oil method was used to prepare foremilk. Through single factor investigation and central composite design-response surface methodology (CCD-RSM) , we optimized the preparation technology and formula respectively. The stability of sub-microemulsion was studied.

RESULTThe optima technology was following: emulsifer in oil method was used to prepare foremilk, temp was 60 degrees C, the micro emulsion was prepared by two-step high pressure homogen method with that the pressure was 80 Pa, 10 times, micropore film was used to sterilize, filling and sealing at the preservation of nitrogen. The best formula was following: soybean oil was 1.1%, DGDG was 1.6%, and sodium oleate was 0. 16%. The particle size of three batch submicro-emulsions were from 168.0 to 169.3 nm; Zeta potential were from-25.53 to 24.90 mV, pH value were from 8.48 to 8.52. The deviation between measured value and predictive value was 1.8%. It was stable in high temperature and illumination.

CONCLUSIONDGDG can be used as the emulsifier of bay oil sub-microemulsion.

Drug Stability ; Emulsifying Agents ; chemistry ; Emulsions ; chemistry ; Galactolipids ; chemistry ; Plant Oils ; chemistry ; Temperature

The feasibility of simultaneously loading both liposoluble and water-soluble components of Salvia miltiorrhiza in emulsion was discussed, in order to provide new ideas in comprehensive application of effective components in S. miltiorrhiza in terms of technology of pharmaceutics. With tanshinone II (A) and salvianolic acid B as raw materials, soybean phospholipid and poloxamer 188 as emulsifiers, and glycerin as isoosmotic regulator, the central composite design-response surface method was employed to optimize the prescription. The coarse emulsion was prepared with the high-speed shearing method and then homogenized in the high pressure homogenizer. The biphasic drug-loading intravenous emulsion was prepared to investigate its pharmaceutical properties and stability. The prepared emulsion is orange-yellow, with the average diameter of 241 nm and Zeta potential of -35.3 mV. Specifically, the drug loading capacity of tanshinone II (A) and salvianolic acid B were 0.5 g x L(-1) and 1 g x L(-1), respectively, with a good stability among long-term retention samples. According to the results, the prepared emulsion could load liposoluble tanshinone II (A) and water-soluble salvianolic acid B simultaneously, which lays a pharmaceutical foundation for giving full play to the efficacy of S. miltiorrhiza.
Chemistry, Pharmaceutical ; instrumentation ; methods ; Drugs, Chinese Herbal ; chemistry ; Emulsions ; chemistry ; Quality Control ; Salvia miltiorrhiza ; chemistry

With the continuous exploration of microemulsions as solvents for traditional Chinese medicine extraction, polyoxyethy-lene(35) castor oil(CrEL), a commonly used surfactant, is being utilized by researchers. However, the problem of detecting residues of this surfactant in microemulsion extracts has greatly hampered the further development of microemulsion solvents. Based on the chemical structures of the components in CrEL and the content determination method of castor oil in the 2020 edition of the Chinese Pharmacopoeia(Vol. Ⅳ), this study employed gas chromatography(GC) and single-factor experiments to optimize the preparation method of methyl ricinoleate from CrEL. The conversion coefficient between the two was validated, and the optimal sample preparation method was used to process microemulsion extracts of Zexie Decoction from three batches. The content of methyl ricinoleate generated was determined, and the content of CrEL in the microemulsion extracts of Zexie Decoction was calculated using the above conversion coefficient. The results showed that the optimal preparation method for CrEL was determined. Specifically, 10 mL of 1 mol·L~(-1) KOH-methanol solution was heated at 60 ℃ for 15 min in a water bath. Subsequently, 10 mL of boron trifluoride etherate-methanol(1∶3) solution was heated at 60 ℃ for 15 min in a water bath, followed by extraction with n-hexane twice. CrEL could stably produce 20.84% methyl ricinoleate. According to this conversion coefficient, the average mass concentration of CrEL in the three batches of Zexie Decoction microemulsion extracts was 11.94 mg·mL~(-1), which was not significantly different from the CrEL mass concentration of 11.57 mg·mL~(-1) during microemulsion formulation, indicating that the established content determination method of this study was highly accurate, sensitive, and repeatable. It can be used for subsequent research on microemulsion extracts of Zexie Decoction and provide a reference for quality control of other drug formulations containing CrEL.
Polyethylene Glycols/chemistry* ; Castor Oil ; Methanol ; Surface-Active Agents/chemistry* ; Solvents ; Water/chemistry* ; Emulsions/chemistry*

To prepare Zhitong micro-emulsion in this study, with the empirical formula of Zhitong preparation as the model medicine, the essential oil in the formula as the oil phase, and the water decoction as the water phase. The types of surfactant and co-surfactant were investigated. The changes in micro-emulsion conductivity and construction, the water percentage in the micro-emulsion system, the changing curve of conductivity and the fine pseudo-ternary phase diagram of micro-emulsion were drawn to determine the surfactant-co-surfactant mass ratio (K(m)). Subsequently, the D-mixture design was used to optimize Zhitong Micro-emulsion formula, with particle size and surface tension of micro-emulsion as the indexes. Finally, efforts were made to determine part of physical parameters of Zhitong micro-emulsion and preliminarily detect its stability. The results showed that the micro-emulsion was optimal with the EL-35-tween 20 ratio of 4:1 in surfactant, whereas the absolute ethyl alcohol was recommended as the co-surfactant. The ratio between surfactant and co-surfactant (K(m)) was 1.5. The finalized micro-emulsion formula contains 12% surfactant, 8% co-surfactant, 70% 1 g x mL(-1) water decoction and 8% oil. The results of the preliminary stability experiment showed a better stability of Zhitong micro-emulsion.
Chemistry, Pharmaceutical ; methods ; Drugs, Chinese Herbal ; chemistry ; Emulsions ; Surface-Active Agents ; chemistry ; Temperature