Water in oil microemulsions containing NaCl for transdermal delivery of fluorouracil / 药学学报

This study is to prepare the W/O microemulsion containing NaCl and fluorouracil (5-Fu) as a model drug to investigate the transdermal characteristics and skin irritation of the microemulsion in vitro. Isopropylmyristate (IPM) acting as oil phase, Aerosol-OT (AOT) as surfactant, Tween 85 as cosurfactant, NaCl solution was added dropwise to the oil phase to prepare W/O microemulsion at room temperature using magnetic stirring, and then 5-Fu powder was added. According to the area of microemulsion based on the pseudo-tertiary phase diagrams, the optimum formulation was screened initially. And the permeation flux of fluorouracil across excised mice skin was determined in vitro using Franz diffusion cells to study the influence of the amount of water and the drug loading capacity and optimize the formulation further. Refer to 5-Fu cream, the irritation of microemulsion on the rat skin was studied. The optimum formulation was composed of 0.7% (w/v) 5-Fu, 50% NaCl solution (0.05 mol x L(-1)), 20% mix-surfactant (AOT/Tween 85, K(m) = 2) and 29.3% oil (IPM). The cumulative amount of fluorouracil permeated in 12 h was (2 013.4 +/- 41.6) microg x cm(-2), 20.23 folds and 10.38 folds more than 0.7% fluorouracil aqueous solution and 2.5% (w/w) fluorouracil cream, respectively. Microemulsion exhibited some irritation, but could be reversed after drug withdrawal. The addition of NaCl significantly increased the content of water and the drug loading in microemulsion systems. The NaCl/AOT-Tween 85/IPM microemulsion system promoted the permeation of fluorouracil greatly, which may be a promising vehicle for the transdermal delivery of fluorouracil and other hydrophilic drug.

Molecular Identification of the Vaccine Strain from the Inactivated Rabies Vaccine

Since 1994, several different inactivated rabies vaccines have been used to immunize domestic animals such as dogs, cats, and cattle in South Korea. The Korean Veterinary Authority has conducted safety and efficacy testes of inactivated vaccines using laboratory animals. In this study, we applied a molecular method to investigate the genetic characterization of the rabies virus (RABV) genes in six commercial inactivated rabies vaccines, and determined the efficiency of two extraction reagents (i.e., sodium citrate or isopropyl myristate) to separate the vaccine antigens from the antigen/adjuvant complexes. Six partial nucleocapsid (N: 181 bp) and five partial glycoprotein (G: 306 bp) genes were successfully amplified with specific primer sets, which demonstrated that sodium citrate is more efficient than isopropyl myristate in extracting viral RNA from inactivated gel vaccines. In addition, we identified the viral strain of the vaccine by analyzing the nucleotide sequences of the N and the G genes. The nucleotide similarity of the partial N and G genes ranged from 97.1 to 99.4% and from 91.8 to 100% among rabies vaccine strains, respectively, indicating that each manufacturer used different rabies virus strains to produce their vaccines. The molecular method used in this study could also be used to identify viral strains in other inactivated vaccines.

Microemulsion-based gel of fluorouracil for transdermal delivery / 药学学报

This study is to prepare the microemulsion-based gel based on the W/O microemulsion and fluorouracil (5-Fu) as a model drug to study the transdermal characterization and observe its skin irritation of the microemulsion-based gel in vitro. IPM acted as oil phase, AOT as surfactant, Tween 85 as cosurfactant, water was added dropwise to the oil phase to prepare W/O microemulsion at room temperature using magnetic stirring, then 5-Fu powder was added. The gelatin was used as substrate to prepare 5-Fu microemulsion-based gel. The permeation flux of 5-Fu from 5-Fu microemulsion-based gel across excised mice skin was determined in vitro using Franz diffusion cell to study the influence of the amount of gelatin and the drug loading capacity. Refer to 5-Fu cream, the irritation of microemulsion and microemulsion-based gel on the rat skin was studied. Based on the water/AOT/Tween 85/IPM microemulsion, only the gelatin can form the microemulsion-based gel. At 25 degrees C, 32 degrees C and 40 degrees C, the amount of gelatin required for the formation of microemulsion-based gel were 7%, 14% and more than 17%, respectively. The 12 h transdermal cumulated permeation amount of 5-Fu from microemulsion-based gel containing 14% gelatin and 0.5% drug loading were (876.5 +/- 29.1) microg x cm(-2), 12.3 folds and 4.5 folds more than 0.5% 5-Fu aqueous solution and 2.5% (w/w) 5-Fu cream, respectively. Microemulsion-based gel exhibited some irritation, but could be subsided after drug withdrawal. Microemulsion-based gel may be a promising vehicle for transdermal delivery of 5-Fu and other hydrophilic drug.

Water in oil microemulsions for transdermal delivery of fluorouracil / 药学学报

An Aersol-OT (AOT) included microemulsion containing fluorouracil was prepared by using appropriate proportion of oil, co-surfactant and water for increasing the drug transdermal delivery ability. According to the area of microemulsion basing on the pseudo-tertiary phase diagrams, the optimum formulation was screened initially. And the permeation flux of fluorouracil across excised mice skin was determined in vitro using Franz diffusion cell to optimize the formulation further. The effect of the kind of co-surfactant, the content of water, the content of mixed surfactant, the mass ratio of surfactant/cosurfactant (Km) and the drug load on skin permeation of fluorouracil were evaluated. The optimum formulation was composed of 0.5% (w/v) fluorouracil, 30% water, 20% mix-surfactant (AOT/Tween 85, Km = 2) and 49.5% oil (IPM). The cumulative amount permeated of fluorouracil in 12 hour was 1 355.5 microg x cm(-2), 19.1 folds and 7 folds more than 0.5% fluorouracil aqueous solution and 2.5% (w/w) fluorouracil cream, respectively. The permeation of this microemulsion accorded with first-order model. The water/AOT/Tween 85/IPM microemulsion system promoted the permeation of fluorouracil greatly, which may be a promising vehicle for the transdermal delivery of fluorouracil and other hydrophilic drug.

Effect of different permeation enhancers on topical miconazole nitrate preparations

Miconazole nitrate was formulated into different topical preparations, including gels with different polymers, ointments as oleaginous, water-soluble bases and cream. In vitro skin permeation studies through rabbit skin to a receptor medium of [1:1] Methanol: phosphate buffer [pH6] For a period of 8 hour was studied. Different chemical enhancers as menthol, isopropyl myristate [IPM], oleic acid and ethanol, were incorporated into miconazole carbopol 934 P gel in different concentrations. They showed improved increase in Flux through rabbit skin. The best formula which showed significant flux was miconazole carbopol 934 p gel containing 10% menthol with the highest permeation of miconazole nitrate

A Case of Allergic Contact Dermatitis from Silmazine(R) Cream / 대한피부과학회지

Silmazine(R) cream is an antibiotic agent widely used in burn therapy. It consists of Propylene glycol, Stearyl alcohol, Isopropyl Myristate, Sorbitan mono-oleate, Methyl-p-hydroxybenzoate, Polyoxyl 40 stearate and varseline. A 24-year- old female presented with well-demarcated erythematous papules and vesicles with an itching sensation on the dorsal area of her right hand. She had applied Silmazine(R) cream on the dorsal area of her right handfor 4 days and the skin lesion became aggravated. A patch test with Silmazine(R) cream 'as is' showed a positive reaction and propylene glycol and stearyl alcohol, ingredients in Silmazine(R) cream, revealed a positive reaction. These two agents are known as weak sensitizers that can produce allergic contact dermatitis. There are some reports of allergic contact dermatitis from propylene glycol and stearyl alcohol used topically. As far as we know, there are no reports of allergic contact dermatitis from propylene glycol and stearyl alcohol in the Silmazine(R) cream (Silver sulfadiazine) that is commonly used as topical antibiotic medication for burns. We report this rare case of allergic contact dermatitis from propylene glycol and stearyl alcohol in Silmazine(R) cream (Silver sulfadiazine).

Study on alpha-asarone reservoir-type patch / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare the alpha-asarone reservoir patch and investigate its release and transdermal absorption characteristics in vitro. The efficient enhancers were chosen to improve the drug's permeation rate.</p><p><b>METHOD</b>The alpha-asarone reservoir patch was prepared using 1% hydroxypropyl methylcellulose (HPMC) of ethanol solution as medium and ethylene vinyl acetate (EVA) membrane to control the release of drug. The Franz diffusion cells were used and several permeation enhancers were evaluated. High performance liquid chromatorgraphy (HPLC) was used to determine alpha-asarone's content and permeation rate.</p><p><b>RESULT</b>The release mechanisms of alpha K-asarone patch in vitro coincided with zero-order kinetic. 30% ethanol cooperates with 1% Isopropyl Myristate (IPM) have the best effect on permeation of the patch. The permeation rate reaches (20.67 +/- 1.33) microg x cm(-2) h(-1).</p><p><b>CONCLUSION</b>Ethanol combined with IPM is good permeation enhancer, which facilitated the permeation of alpha K-asarone to fit the clinical requirements. However, the further studies of the skin's stimulation and bioavailability are needed.</p>

Isopropyl myristate molecular gels and drug-loaded transdermal capability / 药学学报

<p><b>AIM</b>To prepare of isopropyl myristate (IPM) molecular gels and investigate of its transdermal capability.</p><p><b>METHODS</b>Microstructure of IPM gels was studied by scanning electron microscope (SEM) and optical microscope (OM). The rheology and thixotropy of IPM gels were investigated by viscosity. Triptolide was used as model drug to investigate its transdermal capability.</p><p><b>RESULTS</b>The microstructure of IPM gels was a three-dimension network formed by the aggregation of Span 60 in IPM, which was rod-like tubular aggregate. It has good rheology and thixotropy. There was a good linear correlation between the accumulative permeated amount per unit area and the time for triptolide-loaded IPM gels. The permeation process agreed with zero order pharmacokinetics. The average permeability through rat skin for triptolide was 19.26 ng x cm(-2) x h(-1), which was 2.92 times of triptolide unguents obtained commercially available.</p><p><b>CONCLUSION</b>Isopropyl myristate molercular gel can be formed by span 60 assemblies. Transdermal capability drug-loaded IPM gels was better than that of triptolide unguents.</p>

Research on components of Cornus officinalis extracted by supercritical carbon dioxide / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of Cornus officinalis extracted by supercritical carbon dioxide fluid extraction (SFE).</p><p><b>METHOD</b>The process was performed at 40 centigrade with pressures of 15 MPa for 2 hours and with CO2 fluid and gas at the flow rate of 22.0 kg x h(-1) and 18.0 kg x h(-1) respectively. The chemical constituents of the SFE extractions were determined by GC-MS.</p><p><b>RESULT</b>The total amount of extractable substances or yields by SFE is 2.42% (mass). 31 Chemical constituents were identified and their relative contents were determined by normalization method of area.</p><p><b>CONCLUSION</b>The major components identified in the extractions are 1,2-benzenedicarboxylic acid, butyl 2-methylpropyl ester, isopropyl myristate etc.</p>

Myristate exchange in glycolipid A and VSG of African trypanosomes

The variant surface glycoprotein (VSG) of T. brucei is anchored to the plasma membrane via a glycosylphosphatidylinositol (GPI) anchor which is unique in that its fatty acids are exclusively myristate (a fourteen carbon saturated fatty acid). We showed that the myristate is added to the GPI precursor in a remodeling reaction involving deacylation and reacylation. We now demonstrate that trypanosomes have a second pathway of myristoylation for GPI anchors that we call "myristate exchange" which is distinct from the fatty acid remodeling pathway. We propose that this is an exchange of [3H]myristate into both sn-1 and sn-2 positions of glycolipid A, which already contains myristate, and have demonstrated this using inhibitors and a variety of other methods. We have partially characterized myristate exchange with respect to specificity and susceptibility to some inhibitors. The apparent Km for myristoyl CoA is 7 nM. This myristate-specific process may represent a proof-reading system to ensure that the fatty acids on VSG are exclusively myristate. Although myristate exchange was first discovered for glycolipid A, we now believe that VSG is the true substrate of this reaction. VSG is efficiently labeled by exchange in the presence of cycloheximide, which prevents anchoring of newly synthesized protein. Although its location is not yet know, we have evidence that exchange does not localize to either the endoplasmic reticulum or the plasma membrane. We will present data indicating that surface VSG may be internalized and undergo myristate exchange