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ABSTRACT: Rhodamine 123 (R123), as a typical of P-gp substrate, was widely used to quantify P-glycoprotein (P-gp) functional efflux activity in vivo. A new, rapid and sensitive method was developed for quantifying R123 in rat plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). R123 and Rhodamine 6G (R6G, the internal standard, IS) were extracted from aliquots of plasma with ethyl acetate and dichloromethane (4:1) as the solvent and chromatographic separation was performed using a Zorbax Eclipse Plus C18 column. The mobile phase was composed of A: ammonium formate-formic acid buffer containing 5 mM ammonium formate and 0.1% formic acid and B: methanol (A:B, 5:95, v/v). To quantify R123 and IS respectively, multiple reaction monitoring (MRM) transition of m/z 345.2→285.2 and m/z 443.3→415.2 was performed. The analysis time was 4 min in positive mode; the calibration curve was linear in the concentration range of 1-200 ng/ml. The lowest limit of quantification (LLOQ) reached 1 ng/ml. The intra and inter-day precision were less than 9.2% for the low quality control (QC) level, and 3.4% for other QC levels, respectively, while the intra and inter-day relative errors ranged between -7.4% and 9.1% for three QC concentration levels. The LC-MS/MS method proved to be simple, accurate, reliable and with a shorter running time and has been successfully applied to evaluate the functional activity of P-glycoprotein in an absorption experiment in the rat.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 12/2011; 879(32):3943-8. · 2.78 Impact Factor
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ABSTRACT: To develop a method for detecting the topical concentration of hydrocortisone (HC) in the subcutaneous adipose of rats using microdialysis sampling technique and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS).
Topical samples were collected by applying the probe into the subcutaneous adipose of rats, with alcohol (5%)-ringers solution as the perfusion solution. A LC-MS/MS method was established for detecting the HC concentration in the dialysates.
The protonated precursor to produce ion transitions monitored for HC was m/z 363.2→121.1. The calibration curve was linear over the range of 0.5-1000 ng/ml, with the intra- and inter-day precision and accuracy within ∓15%, and no significant matrix effect was noted. The in vivo recovery of the probe was about 59%.
A selective and sensitive method has been successfully established for the on-line HC detection in the subcutaneous adipose of rats.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 08/2011; 31(8):1387-91.
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ABSTRACT: To study the effect of podophyllotoxin nanostructured lipid carriers (POD-NLC) on immortalized human cervical epithelial cells (H8) infected with HPV in vitro.
POD-NLC was prepared by emulsion evaporation method and characterized using transmission electron microscopy, Zetasizer analyzer and high-performance liquid chromatography (HPLC). H8 cells were treated with different concentrations (0.0001-1 µg/ml) of POD-NLC, free POD, or blank nanostructured lipid carriers (NLC), and the cell proliferation was assessed using MTT assay to evaluate the cytotoxic effects. The changes of cell morphology were observed using fluorescence microscopy, and the cell cycle changes and cell apoptosis were analyzed using flow cytometry.
POD-NLC showed a spherical or elliptical shape with good stability in vitro. The average particle size of POD-NLC was 85.6∓10.25 nm, with a Zeta potential of 26.2∓4.1 mV and entrapment efficiency of POD of (88.56∓3.1)%. POD-NLC caused a significant inhibition of H8 cell proliferation in a concentration- and time-dependent manner. At an equivalent concentration, POD-NLC produced a stronger inhibitory effect on cell proliferation than POD. The inhibition rate of H8 cells after a 48-h exposure to POD-NLC and POD reached 95.8% and 65.6%, respectively, and at the highest concentration of 1 µg/ml, the IC(50) of POD-NLC and POD was 0.015 µg/ml and 0.13 µg/ml, respectively. Blank NLC did not obviously affect the proliferation of H8 cells. POD-NLC and POD both caused obvious increases in G(2)/M phase cell percentages and induced typical apoptotic changes of the cells, and their effects were comparable (P>0.05).
Compared with POD, POD-NLC has more potent effect in inhibiting H8 cell proliferation and inducing cell apoptosis, suggesting its potential in the treatment of cervical HPV infection.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 06/2011; 31(6):1023-8.
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ABSTRACT: To develop and validate a sensitive method for quantitative analysis of podophyllotoxin in blood and dermal microdialysis samples of rats based on liquid chromatography-tandem mass spectrometry (UFLC-MS-MS).
The microdialysis samples were prepared by liquid-liquid extraction using ethyl acetate with etoposide as the internal standard (IS). Podophyllotoxin was separated with an Agilent ZORBAX XDB-C18 column (2.1 mmx50 mm, 3.5 microm). The mobile phase consisted of acetonitrile: 10 mmol/L ammonium acetate (40:60, V/V) at a flow rate of 0.3 ml/min and the analysis was performed at the ambient temperature. The UFLC-MS/MS system was operated in the mode of multiple reaction monitoring using the electrospray ionization technique in positive mode.
Podophyllotoxin and etoposide responses were optimized at the transitions m/z 432.7-->397.3 and 589.5-->229.5, respectively. Calibration curves were linear over the range 2.0-1000 ng/ml. The lowest limits of quantification and detection values were 2.0 ng/ml and 0.7 ng/ml, respectively. The inter- and intra-day precision and accuracy were both less than 15%.
This selective and sensitive method can be used to quantity podophyllotoxin in the blood and dermal microdialysates of rats.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 06/2010; 30(6):1256-9, 1267.
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ABSTRACT: To investigate the effect of imatinib on rat C6 glioma cell apoptosis and cell cycle.
MTT assay was used to determine the OD value of C6 glioma cells following treatment with imatinib at different concentrations (0.156, 10 and 15 micromo/L) for 24, 48 and 72 h. The cell apoptosis was assayed by Hochest/PI staining and the cell cycle changes were analyzed by flow cytometry.
Imatinib treatment resulted in increased number of apoptotic cells in a time- and dose-dependent manner. A 72-h treatment of the cells with imatinib at 10 and 15 micromo/L caused increased cell percentage in G(0)/G(1) phase to (68.53-/+0.83)% and (70.41-/+0.62)%, (P<0.01), decreased the percentage of G(2) phase cells to (14.48-/+0.12)% and (13.84-/+2.86)% (P<0.01), and decreased the percentage of S phase cells to (16.98-/+0.72)% and (15.78-/+2.28)%, respectively (P<0.01).
Imatinib can induce apoptosis and affect the distribution of the cell cycle of C6 cells in vitro.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 05/2010; 30(5):1089-91.
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ABSTRACT: To evaluate the effect of different preparation methods on the encapsulation efficiency (EE) and drug loading (DL) of paclitaxel-loaded polybutylcyanoacrylate nanoparticles (PTX-PBCA-NPs) and optimize the preparation of PTX-PBCA-NPs.
With DL and EE as the major indexes, the qualities of PTX-PBCA-NPs produced by the interfacial polymerization and emulsion polymerization method were compared. The optimized prescription was obtained by orthogonal design.
The ranges of EE of PTX-PBCA-NPs with the two methods were both 94.39%-99.23%. The highest DL with interfacial polymerization was (1.07-/+0.03)%, as compared to (0.86-/+0.01)% with emulsion polymerization. The optimized preparation conditions resulted in the mean size of PTX-PBCA-NPs of 235.6 nm, DL of 0.80%, and EE of 95.71%.
The EE of PTX-PBCA-NPs prepared by the above two methods is consistent with the requirement of the Pharmacopoeia of China, and PTX-PBCA-NPs containing higher DL can be obtained via interfacial polymerization.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 04/2010; 30(4):763-6.
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ABSTRACT: To investigate the modulation on the P-glycoprotein in the jejunum by combined use of Glycyrrhiza inflata and Kansui with ussing chamber and rt-pcr, Rhodamine 123 (R123), a P-gp substrate and fluorescein sodium (CF), a model drug of non-P-gp substrate transported by a passive diffusion were taken as investigational drugs. Because these two drugs can be easily assayed and widely used in various research fields. The permeability of R123 or CF via Wistar rat jejunum membranes was evaluated by in vitro ussing chamber after oral administration of four different decoctions of Glycyrrhiza inflata and Kansui for 1 week. And the concentration of R123 or CF was determined by the fluorospectrophotometry in the receiving solution. Meanwhile the expression of mdr1a in P-glycoprotein was detected by real-time fluorescent quantitative PCR. After oral administration of combined decoction of the single drug, the absorptive directed permeability of R123 increased significantly (P < 0.01). On the other hand, Kansui and combine decoction of the two drugs also decrease the permeability of secretory directed transport (P < 0.05). No action of Glycyrrhiza inflata was found on the secretory transport of R123 [Papp = (2.56 +/- 0.38) x 10(-5), cm x s(-1)] across the jejunum tissues, while Papp of control group was found [Papp = (2.35 +/- 0.27) x 10(-5), cm x s(-1)]. After oral administration of Kansui decoction for 1 week and 2 weeks, the levels of mdr1a expression in Wistar rats were lower than that of the control group, but there were no significant difference in the results. Meanwhile, Glycyrrhiza inflata had no effect on transport of CF across the jejunum tissues, though the other three groups could decrease the permeability of CF, as compared with control group. Kansui may slightly inhibit P-glycoprotein function in the intestinal membrane. For another, some compositions in Kansui inhibit P-glycoprotein function, and some others strengthen the tight junction between cells in the intestinal membrane to decrease permeability of CF. As the inhibitory action to P-glycoprotein was enhanced by combination of Glycyrrhiza inflata and Kansui, based on the results, it may be one of the mechanisms of creating toxicity once co-administration of Glycyrrhiza inflata and Kansui.
Yao xue xue bao = Acta pharmaceutica Sinica 04/2010; 45(4):510-6.
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ABSTRACT: To prepare lidocaine nanoemulsion and investigate its transdermal delivery ability in vitro.
The optimal Km (surfactant/cosurfactant) value and the component proportion were determined by pseudoternary phase diagrams combined with Origin software analysis. The diameter and distribution range were detected by Zeta particle size analysis instrument, and the morphology of the nanoemulsion was observed by electron microscope. The permeation flux of lidocaine was determined in vitro using the modified Franz diffusion cell combined with HPLC, and the cumulative transdermal absorption amount and the apparent skin transdermal velocity were compared among nanoemulsion, gel and tincture containing 5% lidocaine. The permeation mode of lidocaine nanoemulsion was analyzed.
The average drop size of lidocaine nanoemulsion was 29.8-/+14.4 nm, and 98% of the drop sizes ranged from 15.1 to 45.5 nm and 2% from 77.9 to 261.3 nm. The nanoemulsion drop showed a spherical morphology in a polydisperse system. The Kp value of the nanoemulsion (3.07-/+0.74 cm/h) was significantly higher than that of gel (1.27-/+0.35 cm/h) and tincture (0.97-/+0.18 cm/h), and the permeation rate of the nanoemulsion was 69.82-/+7.48 microg x cm(-2) x h(-1), which fitted the the Zero-order release dynamic procedure.
The component proportion of lidocaine nanoemulsion can be conveniently obtained through pseudoternary phase diagrams and Origin software analysis, and the drop size, distribution, morphology and system type can be determined by Malvern Zetasizer combined with electron microscopy. The results also indicate that the nanoemulsion system with high permeation rate may provide a new promising means for local anesthesia.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 03/2010; 30(3):451-4.
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ABSTRACT: To compare the therapeutic effects of minocycline, metronidazole and iodine glycerin on periodontitis.
A total of 123 patients were randomly divided into 3 groups to receive the 3 topical remedies administered into the periodontal pockets. The total response rate of the 3 treatments was calculated, and the changes in GI, PL I, PD and BO P were observed.
All the clinical indices of the 3 groups showed obvious improvements after the treatments compared with the baseline levels. The clinical indices of minocycline group and metronidazole group showed significant greater improvements than those of iodine glycerin group. The total response rate in minocycline group and metronidazole group was higher than that of iodine glycerin group.
Minocycline and metronidazole as topical remedies can be effective auxiliary treatments of periodontitis.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 03/2010; 30(3):611-3.
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ABSTRACT: To examine the histological changes of diabetic rats' skin and the effects on the percutaneous absorption of hydrocortisone (HC, a glucocorticoid), male Wistar rats were randomly divided into five groups: control group, diabetes one-week group (W1), two-week group (W2), three-week group (W3), and four-week group (W4), while each group contained 6 rats. Diabetes mellitus (DM) rat model was prepared with the method of streptozocin (STZ, 40 mg x kg(-1)) intraperitoneal injection. Abdominal skin was cut to carry out an in-vitro penetration experiment on an improved Franz diffusion cells, and phosphate buffer (PBS, pH 7.4) was used as receptor solution. The solution was analyzed with HPLC, and then the penetrating rate can be calculated. Meanwhile, rats' abdominal skins of different DM periods were HE stained and made into tissue slices to find if any histological changes occurred. The penetrating rate of control, W1, W2, W3, and W4 groups were 2.39 +/- 1.25, 3.22 +/- 1.72, 3.02 +/- 1.89, 3.63 +/- 2.02 and 5.00 +/- 3.36 microg x h(-1) x cm(-2), respectively. There was significant difference between the control and the W4 group (P < 0.05), but no significant differences were found between any other two groups (P > 0.05). The tissue slices showed that compared to the normal rats' skin, little change was observed in one-week DM rats' skin, but the skin of one-month DM rats' skin was observed thinner, and it became much thinner than that of rats with two-month diabetes, especially the epidermis. After making a rat into diabetic, the rats' skin goes through a pathological change, and this change is closely interrelated with the increase of the permeation of HC. Therefore, it is necessary to adjust the dose while some drug was applied on the skin in case of diabetes mellitus.
Yao xue xue bao = Acta pharmaceutica Sinica 01/2010; 45(1):114-9.
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ABSTRACT: To investigate the effect of liquorice in functional modulation of intestinal P-glycoprotein (P-gp) in rats.
An in vitro diffusion chamber system (Ussing chamber) was used to examine the direct effect of liquorice decoction on rhodamine 123 (a subtrate of P-gp) transport and evaluate the permeability of rhodamine 123 or fluorescein sodium through rat jejunum membranes after oral administration of liquorice decoction.
Direct application of liquorice decoction did not obviously affect rhodamine 123 transport across the intestinal mucosa. Oral administration of liquorice decoction (10 g/kg, twice daily for a week) significantly increased the absorption of rhodamine 123 and also enhanced rhodamine 123 secretion across the jejunum mucosa. Liquorice had no obvious effect on the transport of CF across the jejunum mucosa.
Liquorice may slightly inhibit P-gp function in the intestinal mucosa to increase the intestinal absorption of rhodamine 123.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 09/2009; 29(8):1571-3.
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ABSTRACT: To investigate the modulation of Glycyrrhiza inflata and Daphne genkwa on the permeability characteristics of rhodamine 123 (R123), one P-glycoprotein (P-gp) substrate, across the jejunum membranes. And then approach the possible permeability mechanism of the drugs after co-administration of G. inflata and D. genkwa in gastrointestinal tract.
The permeability of R123 or fluorescein sodium (CF) via Wistar rat jejunum membranes was evaluated by in vitro diffusion chamber system after oral administration of four different decoctions and 0.9% sodium chloride (20 mL x kg(-1)) for 1 week. And the concentration of R123 or CF was determined by the fluorospectrophotometry. The apparent permeability coefficient (P(app)) was calculated by the equation P(app) = dQ/d(t) x (1/A x C0), where P(app) was expressed in cm/s, dQ/dT was the slope of the linear portion of the permeation curves, A was the diffusion area, and C0 was the initial concentration of rebamipide in the donor side, and then compare their differences were compared with control group.
After oral administration of G. inflata decoction, D. genkwa decoction and decoction of the combination of the previous decoctions, the absorptive directed transport of R123 was significantly increased (P < 0.05, compared with control group). On the other hand, D. genkwa could also decrease the permeability of secretory directed transport (P(app) = 2.98 +/- 0.59), while no action of G. inflata was found on the secretory transport of R123 ( P(app) = 5.24 +/- 3.98) across the jejunum tissues, while P(app) of control group was 4.38 +/- 1.18. Meanwhile, G. inflata had no effect on transport of CF across the jejunum tissues, though the other three groups could decrease the permeability of CF, as compared with control group.
G. inflata may slightly inhibit P-glycoprotein function in the intestinal membrane, while D. genkwa may be a relatively strong inhibitor of P-gp. For another, some compositions in D. genkwa inhibit P-gp function, and some others strengthen the tight junction between cells in the intestinal membrane to decrease permeability of CF. As the inhibitory action to P-gp was enhanced by combination of G. inflata and D. genkwa, based on the results, it may be one of the mechanisms of creating toxicity once co-administration of G. inflata and D. genkwa.
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 11/2008; 33(21):2521-6.
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ABSTRACT: To investigate the permeability characteristics of rebamipide across intestinal mucosa, and examine the effects of some absorption enhancers on the permeability across the colonic tissue. Another purpose is to demonstrate the colon-specific delivery of rebamipide with or without absorption enhancers using chitosan capsule as a carrier.
The permeability of rebamipide was evaluated using an in vitro diffusion chamber system, and the effects of some absorption enhancers on the permeability via colon were further investigated. The release of rebamipide from chitosan or gelatin capsule was studied by Japan Pharmacopoeia rotating basket method. The colonic and plasma concentrations were analyzed by high performance liquid chromatography (HPLC) to evaluate colon-targeting action after oral administration of various dosage forms, and rebamipide with absorption enhancers in chitosan dosage forms.
The permeability of rebamipide across the jejunal or ileal membranes was higher than the colonic membranes. Both sodium laurate (C12) and labrasol significantly increased permeability across the colon membranes. On the other hand, the release of rebamipide from chitosan capsule was less than 10% totally within 6 h. The area under concentration-time profile of drug in the colon mucosa using chitosan capsules (AUCLI, 16011.2 ng x h/g) was 2.5 times and 4.4 times greater than using gelatin capsules and CMC suspension, respectively. Meanwhile, the area under concentration-time profile of drug in the plasma (AUCPL) was 1016.0 ng x h/mL for chitosan capsule, 1887.9 ng x h/mL for CMC suspension p and 2163.5 ng x h/mL for gelatin capsule. Overall, both AUCLI and AUCPL were increased when C12 was co-administrated, but the increase of AUCLI was much greater; the drug delivery index (DDI) was more than 1 compared with simple chitosan capsule group.
There was a regional difference in the permeability of Rabamipide across the jejunum, ileum and the colon, and passive diffusion seems to be one of the major transport mechanisms of rebamipide. Absorption enhancers can increase the permeability of rebamipide across the colon tissue significantly. In addition, chitosan capsule may be a useful carrier to deliver rebamipide to the colon specifically and the co-administration of C12 with rebamipide may also be very useful in local treatment.
World Journal of Gastroenterology 09/2008; 14(31):4928-37. · 2.47 Impact Factor
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ABSTRACT: To investigate the effect of Tween-80 in modulating rhodamine123 (R123) permeability across the intestinal membranes.
The permeability of R123 or fluorescein sodium (CF) across isolated rat intestinal membranes at the concentration of 5 microg/ml was evaluated using an in vitro diffusion chamber system, in the presence or absence of Tween-80 at different low concentrations. The concentration of R123 or CF in the receptor chamber was determined using fluorospectrophotometry.
The intestinal membrane permeability of R123 gradually decreased from the jejunum to the ileum and then to the colon. The serosal-to-mucosal transport of R123 was much greater than its mucosal-to-serosal transport. In the presence of low concentrations of Tween-80, the absorptive transport of R123 was significantly increased while its secretory transport decreased depending on the concentration of Tween-80. However, Tween-80 at the experimental concentrations was found to obviously affect the CF transport across the intestinal membranes.
Low concentrations of Tween-80 may promote the absorption of P-gp-mediated drugs and therefore improve the oral bioavailability of these drugs.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 05/2008; 28(4):579-81.
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ABSTRACT: To evaluate the anti-proliferative and apoptosis-inducing effect of podophyllotoxin solid lipid nanoparticles (PDP-SLN) in human cervical carcinoma cells in vitro.
Hela cells were treated with PDP and PDP-SLN at different concentrations (0.0005-5 micromol/L), and the proliferation of the cells was assessed using MTT assay and the apoptotic index was determined by flow cytometry.
Both PDP and PDP-SLN showed obvious inhibitory effect on the cell proliferation in a dose- and time-dependent manner. At the same concentration, PDP-SLN produced stronger inhibitory effect on the cells than PDP, with IC50 24, 48, and 72 h after the cell exposure to PDP-SLN and PDP of 4.10, 0.65, 0.20 micromol/L and 9.2, 4.0, 1.3 micromol/L, respectively. Both PDP and PDP-SLN significantly induced the apoptosis of the Hela cell, and the apoptosis rates of the cells incubated in the presence of 0.5 micromol/L PDP-SLN reached 90.8% at 24 h and 94.2% at 72 h, significantly higher than the rate of cells incubated with PDP (64.1% at 24 h and 68.4% at 72 h, P<0.01).
PDP-SLN can effectively suppress the proliferation and induce apoptosis of Hela cells in vitro.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 05/2008; 28(5):786-8.
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ABSTRACT: The objective of this study is to investigate the permeabilities of rebamipide across the jejunal, ileal and colonic membranes in rat. The permeability (Papp) of rebamipide via rat intestinal membranes at concentration of 80 micromol L(-1) was evaluated by an in vitro diffusion chamber system after the membranes were isolated from the rat intestine. And the concentration of rebamipide in the receptor was determined by HPLC. As a result, the permeability of rebamipide across the jejunal or ileal membrane was higher than that across the colonic membrane, and the permeability of rebamipide in the ileal tissue from the serosal to mucosal direction was greater than that from the mucosal to serosal direction. Therefore, there was a regional difference in the permeability of rabamipide across the jejunum, ileum and the colon in rat. Also, the transporters in the intestinal mucosa as p-glycoprotein may not be involved in the transport of rebamipide.
Yao xue xue bao = Acta pharmaceutica Sinica 03/2008; 43(3):314-7.
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ABSTRACT: To observe the clinical efficacy and safety of podophyllotoxin delivered via solid lipid nanoparticle gel for topic treatment of recurrent condyloma acuminatum.
In a randomized double-blinded study, podophyllotoxin solid lipid nanoparticles gel and routine podophyllotoxin gel preparation was applied respectively for treatment of 97 volunteer patients with recurrent condyloma acuminatum. The therapeutic effect, condyloma acuminatum relapse following the treatment and adverse effect were evaluated.
The wart clearance rate in the condyloma acuminatum patients in the first treatment course with podophyllotoxin solid lipid nanoparticle gel reached 97.1%, close to that with the routine preparation of 90.6%, but the nanoparticle preparation significantly reduced the recurrence rate and adverse effect (P<0.01).
Podophyllotoxin delivered via solid lipid nanoparticle gel can effectively clear condyloma acuminatum and reduce its recurrence rate with only mild, tolerable adverse effect.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 06/2007; 27(5):657-9.
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ABSTRACT: To compare lidocaine tincture and microemulsion for their transdermal permeation.
The experimental model for percutaneous administration of lidocaine preparations in vitro was prepared using modified Franz diffusion cell.
The accumulated infiltration amount of lidocaine microemulsion in unit area was higher than that in its cream or tincture preparations.
The transdermal permeation of lidocaine microemulsion in vitro can be more efficient than that of the tincture preparation, and the permeation is linearly dependent on the dose administered within a certain range.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 05/2007; 27(4):541-2.
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ABSTRACT: To prepare and determine the proportion of the components of lidocaine microemulsion.
Pseudoternary phase diagrams of the prepared lidocaine microemulsion with different Km (surfactant/cosurfactant) were generated to determine the optimal Km according to the size of the microemulsion area. The diameter and its distribution range, viscosity, electric conductivity and refractivity of lidocaine microemulsion drop was determined, and the appearance and system type of the microemulsion was observed using electron microscope. RESULTS; Maximum microemulsion area in the pseudoternary phase diagrams was obtained with the Km of 3, and the drop size of the microemulsion averaged 29.8+/-14.4 nm (with up to 98% of the drop size ranging between 15.1-45.5 nm and 2% between 77.9-261.3 nm). At 25 degrees C, the viscosity, electric conductivity and refractivity of the microemulsion was 25 mPa.S, 130 micros/cm and 1.473, respectively, and the lidocaine microemulsion was identified to belong to O/W type. The microemulsion drop appeared in spherical shape of heterogeneous sizes in a multi-disperse system.
The optimal proportion of the components in lidocaine microemulsion can be obtained by analyzing pseudoternary phase diagrams, and the drop size, distribution, shape and system type can be determined or observed through Maerwen Zetasizer combined with electron microscopic observation.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 05/2006; 26(4):515-7, 525.
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ABSTRACT: To prepare oral liposome-encapsulated recombinant Helicobacter pylori (Hp) heat shock protein 60 (Hsp60) vaccine and investigate its effect against Hp infection in mice.
The recombinant vector PET-22(+)/Hsp60 was transformed into BL21(DE3) E.coli. The recombinant protein was purified with Ni-NTA agrose resin and the oral liposome-encapsulated vaccine was prepared with phosphatidyl choline and cholesterols using film method, with the size distribution of the folate liposomes measured by transmission electronic microscopy. BALB/c mice were divided into 5 groups and immunized by intragastric administration of PBS, liposome, rHsp60 plus choleratoxin (CT), liposome-encapsulated rHsp60, and liposome-encapsulated rHsp60 plus CT, respectively, given once a week for 4 weeks. All the mice were challenged by Hp for 3 times within two weeks following the last immunization and sacrificed 3 weeks after the last challenge. Hp detection was performed by fast urease test. Semi-quantitative assessment of the bacterial colonization density observation of the inflammation severity and gastric histopathology were carried out.
The soluble expression product accounted for 27% of the total bacterial protein. The purity of recombinant fusion protein was about 95% after purification. The mean size of the folate liposomes was 0.7+/-0.4 mum. PBS or liposome alone showed no immune-enhancing effect, and rHsp60 plus CT, liposome-encapsulated rHsp60 and liposome-encapsulated rHsp60 plus CT had the protective rates against Hp infection of 73.3%, 66.7% and 86.7%, respectively. The latter 3 preparations effected significantly reduced Hp infection and alleviated the inflammation in the gastric mucosa of the mice challenged with Hp.
The oral liposome may serve as a potential adjuvant for Hp vaccine in preventing Hp infection.
Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA 06/2005; 25(5):531-4.
