共查询到20条相似文献,搜索用时 15 毫秒
1.
The purpose of this work was to develop w/o emulsions that could be safely used to promote transdermal delivery of 5-fluorouracil
(5-FU). Two pseudo-ternary phase diagrams comprising oleoyl-macrogol glycerides, water, and a surfactant/co-surfactant (S/CoS)
mixture of lecithin, ethanol, and either coco glucoside or decyl glucoside were investigated for their potential to develop
promising 5-FU emulsions. Six systems were selected and subjected to thermodynamic stability tests; heat–cool cycles, centrifugation,
and finally freeze–thaw cycles. All systems passed the challenges and were characterized for transmission electron microscopy,
droplet size, rheological behavior, pH, and transdermal permeation through newly born mice skin in Franz diffusion cells.
The systems had spherical droplets ranging in diameter from 1.81 to 2.97 μm, pH values ranging from 7.50 to 8.49 and possessed
Newtonian flow. A significant (P < 0.05) increase in 5-FU permeability parameters as steady-state flux, permeability coefficient was achieved with formula
B5 comprising water (5% w/w), S/CoS mixture of lecithin/ethanol/decyl glucoside (14.67:12.15:18.18% w/w, respectively) and oleoyl-macrogol glycerides (50% w/w). When applied to shaved rat skin, this system was well tolerated with only moderate skin irritation that was recovered within
12 h. Indeed, minor histopathologic changes were observed after 5-day treatment. Further studies should be carried out, in
the future, to investigate the potentiality of this promising system to promote transdermal delivery of 5-FU through human
skin. 相似文献
2.
Adnan Azeem Farhan J. Ahmad Roop K. Khar Sushama Talegaonkar 《AAPS PharmSciTech》2009,10(4):1093-1103
The purpose of the present study was to investigate the potential of nanoemulsions as nanodrug carrier systems for the percutaneous
delivery of ropinirole. Nanoemulsions comprised Capryol 90 as the oil phase, Tween 20 as the surfactant, Carbitol as the cosurfactant,
and water as an external phase. The effects of composition of nanoemulsion, including the ratio of surfactant and cosurfactant
(S
mix) and their concentration on skin permeation, were evaluated. All the prepared nanoemulsions showed a significant increase
in permeation parameters such as steady state flux (J
ss) and permeability coefficient (K
p) when compared to the control (p < 0.01). Nanoemulsion composition (NEL3) comprising ropinirole (0.5% w/w), Capryol 90 (5% w/w), S
mix 2:1 (35% w/w), and water (59.5% w/w) showed the highest flux (51.81 ± 5.03 μg/cm2/h) and was selected for formulation into nanoemulsion gel. The gel was further optimized with respect to oil concentration
(Capryol 90), polymer concentration (Carbopol), and drug content by employing the Box–Behnken design, which statistically
evaluated the effects of these components on ropinirole permeation. Oil and polymer concentrations were found to have a negative
influence on permeation, while the drug content had a positive effect. Nanoemulsion gel showed a 7.5-fold increase in skin
permeation rate when compared to the conventional hydrogel. In conclusion, the results of the present investigation suggested
a promising role of nanoemulsions in enhancing the transdermal permeation of ropinirole. 相似文献
3.
Mrunali R. Patel Rashmin B. Patel Jolly R. Parikh Ajay B. Solanki Bharat G. Patel 《AAPS PharmSciTech》2009,10(3):917-923
The purpose of this study was to evaluate the effect of formulation components on the in vitro skin permeation of microemulsion drug delivery system containing fluconazole (FLZ). Lauryl alcohol (LA) was screened as the
oil phase of microemulsions. The pseudo-ternary phase diagrams for microemulsion regions were constructed using LA as the
oil, Labrasol (Lab) as the surfactant and ethanol (EtOH) as the cosurfactant. The formulation which showed a highest permeation
rate of 47.15 ± 1.12 μg cm−2 h−1 and appropriate physicochemical properties was optimized as containing 2% FLZ, 10% LA, 20% Lab/EtOH (1:1), and 68% double-distilled
water (w/w). The efficiency of microemulsion formulation in the topical delivery of FLZ was dependent upon the contents of water and
LA as well as Lab/EtOH mixing ratio. It was concluded that the percutaneous absorption of FLZ from microemulsions was enhanced
with increasing the LA and water contents, and with decreasing the Lab/EtOH ratio in the formulation. Candida albicans was used as a model fungus to evaluate the antifungal activity of the best formula achieved, which showed the widest zone
of inhibition as compared to FLZ reference. The studied microemulsion formulation showed a good stability for a period of
3 months. These results indicate that the studied microemulsion formulation might be a promising vehicle for topical delivery
of FLZ. 相似文献
4.
Formulation Development and Bioavailability Evaluation of a Self-Nanoemulsified Drug Delivery System of Oleanolic Acid 总被引:1,自引:0,他引:1
Jia Xi Qi Chang Chak K. Chan Zhao Yu Meng Geng Nan Wang Jia Bei Sun Yi Tao Wang Henry H. Y. Tong Ying Zheng 《AAPS PharmSciTech》2009,10(1):172-182
This study aims to formulate and evaluate bioavailability of a self-nanoemulsified drug delivery system (SNEDDS) of a poorly
water-soluble herbal active component oleanolic acid (OA) for oral delivery. Solubility of OA under different systems was
determined for excipient selection purpose. Four formulations, where OA was fixed at the concentration of 20 mg/g, were prepared
utilizing Sefsol 218 as oil phase, Cremophor EL and Labrasol as primary surfactants, and Transcutol P as cosurfactant. Pseudo-ternary
phase diagrams were constructed to identify self-emulsification regions for the rational design of SNEDDS formulations. Sefsol
218 was found to provide the highest solubility among all medium-chained oils screened. Efficient self-emulsification was
observed for the systems composing of Cremophor EL and Labrasol. The surfactant to cosurfactant ratio greatly affected the
droplet size of the nanoemulsion. Based on the outcomes in dissolution profiles, stability data, and particle size profiles,
three optimized formulations were selected: Sefsol 218/Cremophor EL/Labrasol (50:25:25, w/w), Sefsol 218/Cremophor EL/Labrasol/Transcutol P (50:20:20:10, w/w), and Sefsol 218/Cremophor EL/Labrasol/Transcutol P (50:17.5:17.5:15, w/w). Based on the conventional dissolution method, a remarkable increase in dissolution was observed for the SNEDDS when compared
with the commercial tablet. The oral absorption of OA from SNEDDS showed a 2.4-fold increase in relative bioavailability compared
with that of the tablet (p < 0.05), and an increased mean retention time of OA in rat plasma was also observed compared with that of the tablet (p < 0.01). These results suggest the potential use of SNEDDS to improve dissolution and oral bioavailability for poorly water-soluble
triterpenoids such as OA. 相似文献
5.
The aim of the present investigation was to evaluate microemulsion as a vehicle for dermal drug delivery and to develop microemulsion-based
gel of terbinafine for the treatment of onychomycosis. D-optimal mixture experimental design was adopted to optimize the amount
of oil (X
1), Smix (mixture of surfactant and cosurfactant; X
2) and water (X
3) in the microemulsion. The formulations were assessed for globule size (in nanometers; Y
1) and solubility of drug in microemulsion (in milligrams per milliliter; Y
2). The microemulsion containing 5.75% oil, 53.75% surfactant–cosurfactant mixture and 40.5% water was selected as the optimized
batch. The globule size and solubility of the optimized batch were 18.14 nm and 43.71 mg/ml, respectively. Transmission electron
microscopy showed that globules were spherical in shape. Drug containing microemulsion was converted into gel employing 0.75%
w/w carbopol 934P. The optimized gel showed better penetration and retention in the human cadaver skin as compared to the commercial
cream. The cumulative amount of terbinafine permeated after 12 h was 244.65 ± 18.43 μg cm−2 which was three times more than the selected commercial cream. Terbinafine microemulsion in the gel form showed better activity
against Candida albicans and Trichophyton rubrum than the commercial cream. It was concluded that drug-loaded gel could be a promising formulation for effective treatment
of onychomycosis. 相似文献
6.
The purpose of the present study was to prepare intranasal delivery system of sildenafil citrate and estimate its relative
bioavailability after nasal administration in rabbits to attain rapid onset of action with good efficacy at lower doses. Sildenafil
citrate saturated solubility was determined in different solvents, cosolvents, and microemulsion systems. For nasal application,
sildenafil citrate was formulated in two different systems: the first was a cosolvent system (S3) of benzyl alcohol/ethanol/water/Transcutol/taurodeoxy
cholate/Tween 20 (0.5:16.8:47.7:15.9:1:18.1% w/w). The second was a microemulsion system (ME6) containing Oleic acid: Labrasol/Transcutol/water (8.33:33.3:16.66:41.66% w/w). The prepared systems were characterized in relation to their clarity, particle size, viscosity, pH, and nasal ciliotoxicity.
In vivo pharmacokinetic performance of the selected system ME6 (with no nasal ciliotoxicity) was evaluated in a group of six rabbits
in a randomized crossover study and compared to the marketed oral tablets. The targeted solubility (>20 mg/ml) of sildenafil
citrate was achieved with cosolvent systems S1, S3, and S5 and with microemulsion systems ME3–ME6. The saturated solubility
of sildenafil citrate in cosolvent system S3 and microemulsion system ME6 were 22.98 ± 1.26 and 23.79 ± 1.16 mg/ml, respectively.
Microemulsion formulation ME6 showed shorter t
max (0.75 h) and higher AUC(0-∞) (1,412.42 ng h/ml) compared to the oral tablets which showed t
max equals 1.25 h and AUC(0-∞) of 1,251.14 ng h/ml after administration to rabbits at dose level of 5 mg/kg. The relative bioavailability was 112.89%. In
conclusion, the nasal absorption of sildenafil citrate microemulsion was found to be fast, indicating the potential of nasal
delivery instead of the conventional oral administration of such drug. 相似文献
7.
Daisuke Sugimori 《Applied microbiology and biotechnology》2009,82(2):351-357
To develop a microbial treatment of edible oil-contaminated wastewater, microorganisms capable of rapidly degrading edible
oil were screened. The screening study yielded a yeast coculture comprising Rhodotorula pacifica strain ST3411 and Cryptococcus laurentii strain ST3412. The coculture was able to degrade efficiently even at low contents of nitrogen ([NH4–N] = 240 mg/L) and phosphorus sources ([PO4–P] = 90 mg/L). The 24-h degradation rate of 3,000 ppm mixed oils (salad oil/lard/beef tallow, 1:1 w/w) at 20°C was 39.8% ± 9.9% (means ± standard deviations of eight replicates). The highest degradation rate was observed at
20°C and pH 8. In a scaled-up experiment, the salad oil was rapidly degraded by the coculture from 671 ± 52.0 to 143 ± 96.7 ppm
in 24 h, and the degradation rate was 79.4% ± 13.8% (means ± standard deviations of three replicates). In addition, a repetitive
degradation was observed with the cell growth by only pH adjustment without addition of the cells. 相似文献
8.
Formulation of a new oil-in-water (o/w) microemulsion composed of castor oil/Tween 80/ethanol/phosphate buffer for enhancing the loading capacity of an anti-inflammatory
drug piroxicam has been accomplished. The pseudo-ternary phase diagram has been delineated at constant surfactant/cosurfactant
ratio (1:2). The internal structure of so created four-component system was elucidated by means of an analysis of isotropic
area magnitudes in the phase diagram. Conductivity (σ), kinematic viscosity (k
η
), and surface tension (γ) studies with the variation in Φ
w (weight fraction of aqueous phase) show the occurrence of structural changes from water-in-oil (w/o) microemulsion to oil-in-water (o/w). Along with the solubility and partition studies of piroxicam in microemulsion components, the changes in the microstructure
of the microemulsion after incorporation of drug have been evaluated using pH, σ, γ, k
η
, and density studies. Piroxicam, a poorly water-soluble drug displayed high solubility (1.0%) in an optimum microemulsion
formulation using ethanol (55.0%), Tween 80 (26.5%), castor oil (7.5%), and phosphate buffer (11.0%). The results have shown
that the microemulsion remained stable after the incorporation of piroxicam. Fluorescence spectra analysis taking pyrene as
fluorescent probe was performed, and the results showed that pyrene was completely solubilized in the oil phases of the bicontinuous
microemulsions. The fluorescence spectrum of the model drug piroxicam was used to probe the intramicellar region of nonionic
microemulsion. The results showed that the piroxicam was localized in the interfacial film of microemulsion systems more deeply
in the palisade layer with ethanol as the cosurfactant. 相似文献
9.
C. J. Baxter N. Magan B. Lane H. G. Wildman 《Applied microbiology and biotechnology》1998,49(3):328-332
A Phoma sp., known to produce the pharmaceutically active metabolites squalestatin 1 (S1) and squalestatin 2 (S2), was cultured on
malt-extract/agar (MEA) over a range of water activities (a
w, 0.995–0.90) and temperatures (10–35 °C) to investigate the influence on growth and metabolite production. Use of the ionic
solute NaCl to adjust a
w resulted in significantly lower (P < 0.01) squalestatin yields than when the Phoma sp. was grown on MEA amended with the non-ionic solute glycerol. Water activity and temperature and their interactions were
highly significant factors (P < 0.001) affecting growth of the Phoma sp., with optimum conditions of 0.998–0.980 a
w and 25 °C. Squalestatin production was similarly influenced by a
w, temperature, time and their interactions (P < 0.001). S1 and S2 production occurred over a narrower a
w and temperature range than growth, with a slightly lower optimum a
w range of 0.995–0.980 a
w. The optimum temperature for squalestatin production varied from 20 °C (S1) to 25 °C (S2) and yields of S2 were up to 1000
times lower than those of S1. The ratio of S1 and S2 produced by the Phoma sp. was influenced by a
w and temperature, with highest values at 0.99–0.98 a
w, and at 15 °C. Incubation times of 28 days gave highest yields of both S1 and S2. Up to 2000-fold increases in squalestatin
yields were measured at optimum environmental conditions, compared to the unmodified MEA. This indicates the need to consider
such factors in screening systems used to detect biologically active lead compounds produced by fungi.
Received: 2 June 1997 / Received last revision: 6 November 1997 / Accepted: 7 November 1997 相似文献
10.
Microemulsions as a tool for the regioselective lipase-catalysed esterification of aliphatic diols 总被引:1,自引:0,他引:1
The efficiency of Humicola lanuginosa and Candida cylindracea lipases to catalyse the regioselective esterification of butane-1,3-diol with oleic acid has been demonstrated in water-in-oil
microemulsion systems stabilized with sodium (bis-2-ethylhexyl) sulphosuccinate as a surfactant in isooctane. Mono- and diesters
were selectively synthesized with high reaction rates. The product distribution depends on the positional specificity of the
lipases. Water-in-oil microemulsions appear to be an effective and fast system for the regioselective enzymatic esterification
of diols.
Received: 29 April 1996 / Received revision: 29 July 1996 / Accepted: 5 August 1996 相似文献
11.
Screening of Venlafaxine Hydrochloride for Transdermal Delivery: Passive Diffusion and Iontophoresis
The objective of the study was to investigate in vitro transdermal delivery of venlafaxine hydrochloride across the pigskin by passive diffusion and iontophoresis. For passive
diffusion, experiments were carried out in Franz diffusion cell whereas for iontophoretic permeation, the diffusion cell was
modified to contain both the donor and return electrode on the same side of skin. Anodal iontophoresis was carried out using
a current density of 0.5 mA/cm2. Donor concentrations used were 585.5 mg/ml (saturated solution) and 100 mg/ml. Experiments initially performed to determine
the transport efficiency of venlafaxine ions showed promising results. Iontophoresis increased the permeation rate at both
concentration levels over their passive counterparts (P < 0.01), but surprisingly higher steady-state flux was obtained from lower donor drug load (P < 0.01). The favorable pH of the unsaturated solutions is suggested to be the cause for this effect. Mild synergistic effect
was observed when iontophoresis was carried out incorporating peppermint oil in the donor but the same was not found in passive
diffusion. Highest steady-state flux obtained in the experiment was 3.279 μmol/cm2/h when peppermint oil (0.1%) was included in the donor. As the maintenance requirement of venlafaxine hydrochloride is approximately
9.956 μmol/h, the results suggested that the drug is a promising candidate for iontophoretic delivery. 相似文献
12.
In order to develop a novel transdermal drug delivery system that facilitates the skin permeation of finasteride encapsulated
in novel lipid-based vesicular carriers (ethosomes)finasteride ethosomes were constructed and the morphological characteristics
were studied by transmission electron microscopy. The particle size, zeta potential and the entrapment capacity of ethosome
were also determined. In contrast to liposomes ethosomes were of more condensed vesicular structure and they were found to
be oppositely charged. Ethosomes were found to be more efficient delivery carriers with high encapsulation capacities. In vitro percutaneous permeation experiments demonstrated that the permeation of finasteride through human cadaver skin was significantly
increased when ethosomes were used. The finasteride transdermal fluxes from ethosomes containing formulation (1.34 ± 0.11 μg/cm2/h) were 7.4, 3.2 and 2.6 times higher than that of finasteride from aqueous solution, conventional liposomes and hydroethanolic
solution respectively (P < 0.01).Furthermore, ethosomes produced a significant (P < 0.01) finasteride accumulation in the skin, especially in deeper layers, for instance in dermis it reached to 18.2 ± 1.8 μg/cm2. In contrast, the accumulation of finasteride in the dermis was only 2.8 ± 1.3 μg/cm2 with liposome formulation. The study demonstrated that ethosomes are promising vesicular carriers for enhancing percutaneous
absorption of finasteride. 相似文献
13.
The benefits of controlling water activity, a
w, during enzymatically catalysed synthesis reactions, such as reverse-hydrolytic reactions promoted by lipases, are now well
recognized. Numerous techniques for controlling a
w in the laboratory and their implementation in continuous reactors have been discussed in the published literature. However,
in enzymatic interesterification reactions, such as acidolysis and transesterification, it is not appropriate merely to maintain
the a
w of the reaction system at one value since the two stages of the reaction, namely the cleavage of the original acyl bond and
the formation of a new one, are best carried out at different levels of water activity – the former at a high a
w and the latter at a lower one. The use of a continuous packed-bed hollow-fibre reactor has been described in this article
for carrying out solvent-free acidolysis of ethyl laurate with octanoic acid with in situ a
w control, using air that has been pre-equilibrated with saturated salt solutions to the desired a
w. At a single optimum (a
w = 0.54), the highest steady-state conversion to ethyl octanoate was 32%. However, it is possible to obtain a steady-state
conversion of 46% by operating the reactor with a step change in the water activity, from an initial value of unity to 0.23.
Received: 10 February 1998 / Received revision: 2 June 1998 / Accepted: 7 June 1998 相似文献
14.
Predawn disequilibrium between plant and soil water potentials in two cold-desert shrubs 总被引:15,自引:0,他引:15
L. A. Donovan D. J. Grisé J. B. West R. A. Pappert N. N. Alder J. H. Richards 《Oecologia》1999,120(2):209-217
Classical water relations theory predicts that predawn plant water potential should be in equilibrium with soil water potential
(soil Ψw) around roots, and many interpretations of plant water status in natural populations are based on this expectation. We examined
this expectation for two salt-tolerant, cold-desert shrub species in glasshouse experiments where frequent watering assured
homogeneity in soil Ψw and soil-root hydraulic continuity and where NaCl controlled soil Ψw. Plant water potentials were measured with a pressure chamber (xylem Ψp) and thermocouple psychrometers (leaf Ψw). Soil Ψw was measured with in situ thermocouple psychrometers. Predawn leaf Ψw and xylem Ψp were significantly more negative than soil Ψw, for many treatments, indicating large predawn soil-plant Ψw disequilibria: up to 1.2 MPa for Chrysothamnus nauseosus (0 and 100 mm NaCl) and 1.8 MPa for Sarcobatus vermiculatus (0, 100, 300, and 600 mm NaCl). Significant nighttime canopy water loss was one mechanism contributing to predawn disequilibrium, assessed by comparison
of xylem Ψp for bagged (to minimize transpiration) and unbagged canopies, and by gas exchange measurements. However, nighttime transpiration
accounted for only part of the predawn disequilibrium. Other mechanisms that could act with nighttime transpiration to generate
large predawn disequilibria are described and include a model of how leaf apoplastic solutes could contribute to the phenomenon.
This study is among the first to conclusively document such large departures from the expectation of predawn soil-plant equilibrium
for C3 shrubs, and provides a general framework for considering relative contributions of nighttime transpiration and other plant-related
mechanisms to predawn disequilibrium.
Received: 12 November 1998 / Accepted: 5 May 1999 相似文献
15.
William J. Trickler Jatin Khurana Ankita A. Nagvekar Alekha K. Dash 《AAPS PharmSciTech》2010,11(1):392-401
The objectives of this study are to enhance cellular accumulation of gemcitabine with chitosan/glyceryl monooleate (GMO) nanostructures,
and to provide significant increase in cell death of human pancreatic cancer cells in vitro. The delivery system was prepared by a multiple emulsion solvent evaporation method. The nanostructure topography, size,
and surface charge were determined by atomic force microscopy (AFM), and a zetameter. The cellular accumulation, cellular
internalization and cytotoxicity of the nanostructures were evaluated by HPLC, confocal microscopy, or MTT assay in Mia PaCa-2
and BxPC-3 cells. The average particle diameter for 2% and 4% (w/w) drug loaded delivery system were 382.3 ± 28.6 nm, and 385.2 ± 16.1 nm, respectively with a surface charge of +21.94 ± 4.37
and +21.23 ± 1.46 mV. The MTT cytotoxicity dose-response studies revealed the placebo at/or below 1 mg/ml has no effect on
MIA PaCa-2 or BxPC-3 cells. The delivery system demonstrated a significant decrease in the IC50 (3 to 4 log unit shift) in
cell survival for gemcitabine nanostructures at 72 and 96 h post-treatment when compared with a solution of gemcitabine alone.
The nanostructure reported here can be resuspended in an aqueous medium that demonstrate increased effective treatment compared
with gemcitabine treatment alone in an in vitro model of human pancreatic cancer. The drug delivery system demonstrates capability to entrap both hydrophilic and hydrophobic
compounds to potentially provide an effective treatment option in human pancreatic cancer. 相似文献
16.
Glibenclamide (GL)-loaded microcapsules (MC) and transdermal patches (TDP) were formulated and in vitro and in vivo parameters compared to find out the best route of drug administration. The formulation TDP1 having a drug–polymer ratio 1:1
showed comparatively higher GL release and better permeation across mice skin (p < 0.05). From the comparative study, it was concluded that the transdermal system of GL produced better improvement compared
to oral microcapsule administration (p < 0.05). The transdermal system exhibited comparatively slow and continuous supply of GL at a desired rate to systemic circulation
avoiding metabolism, which improved day-to-day glycemic control in diabetic subjects. Transdermal system of GL exhibited better
control of hyperglycemia and prolonged plasma half-life by transdermal systems (9.6 ± 1.2 h) in comparison with oral microcapsule
(5.84 ± 2.1 h), indicating that the drug, when administered by transdermal systems, will remain in the body for a longer period.
From the glucose tolerance test, transdermal route effectively maintained the normoglycemic levels in contrast to the oral
group (MC1), which produced remarkable hypoglycemia ranging from −12.6 ± 2.1% to −18 ± 2.3%. The significantly high (p < 0.05) area under the curve values observed with transdermal system (1,346.2 ± 92.3 ng ml−1 h−1) also indicate increased bioavailability of the drug from these systems compared to the oral route (829.8 ± 76.4 ng ml−1 h−1). 相似文献
17.
Meloxicam gel was designed based on the matching of the solubility parameter (δ) of the drug with that of the polymer and subsequently with skin for improved dermal delivery of meloxicam. The δ of meloxicam (11.48 (cal/cm3)0.5) determined by solubility measurement was matched statistically to the solubility parameter of monomers, n-vinyl-2-pyrrolidone, polyvinyl alcohol (PVA), hydroxyl ethyl methacrylate, ethylene glycol methacrylate (EGMA) determined
by intrinsic viscosity measurement. Consequently gels were formulated by polymerization in selected solvent blend of water/ethyl
acetate (20:80) in which the drug showed maximum solubility. Thus, F1–F16 formulations designed were evaluated for physicochemical
properties, textural analysis, and in vitro drug release. On the basis of optimum characteristics, F2 (PVA, δ = 16.96 (cal/cm3)0.5) and F8 (EGMA, δ = 18.35 (cal/cm3)0.5) formulated by suspension polymerization were selected and subjected to skin irritation and topical anti-inflammatory studies.
The formulation F8 demonstrated significant (p < 0.05) of anti-inflammatory activity in comparison to marketed piroxicam gel and was free from irritation. 相似文献
18.
Amin O. Elzupir Mohammed A. Suliman Ibrahim A. Ibrahim M. Himmat Fadul Abdelrahim M. Elhussein 《Mycotoxin Research》2010,26(2):69-73
Vegetable oil (n = 81) for human consumption from Khartoum State in Sudan were analyzed for aflatoxins (AFs), using high-performance liquid
chromatography (HPLC) with fluorescence detection following extraction with methanol:water (80:20) and clean-up using petroleum
ether. Sampling included sesame oil (n = 14), peanut oil (n = 21), and sunflower oil (n = 19) purchased from retail shops, and mixed oil produced by two local manufacturers (factory A, n = 15; factory B, n = 12). AF contamination was found in 80/81 (98.8%) samples, with total AF levels ( AFB1 + AFB2 + AFG1 + AFG2 ) \left( {{\hbox{AF}}{{\hbox{B}}_{\rm{1}}} + {\hbox{AF}}{{\hbox{B}}_{\rm{2}}} + {\hbox{AF}}{{\hbox{G}}_{\rm{1}}} + {\hbox{AF}}{{\hbox{G}}_{\rm{2}}}} \right) of 0.43–339.9 μg/kg and mean level of 57.5 μg/kg. All sesame oils had total AF levels that were much higher than the United
States Food and Drug Administration acceptable limit of 20 μg/kg. The percentage of samples with total AF values <20 μg/kg
in other oils varied and was 57.14% in peanut oil, 36.8% in sunflower oil, 66.7% (mixed oil from factory A), and 91.7% (mixed
oil from factory B). In conclusion, the levels of total AFs in edible oil as available in Khartoum State are quite alarming.
To reduce the health hazards for the consumers, an intervention strategy to manage AFs in food commodities from Sudan is urgently
required. 相似文献
19.
The present investigation aims at developing microemulsion-based formulations for topical delivery of acyclovir. Various microemulsions
were developed using isopropyl myristate/Captex 355/Labrafac as an oil phase, Tween 20 as surfactant, Span 20 as cosurfactant,
and water/dimethylsulfoxide (1:3) as an aqueous phase. Transcutol, eucalyptus oil, and peppermint oil were used as permeation
enhancers. In vitro permeation studies through laca mice skin were performed using Franz diffusion cells. The optimum formulation containing
2.5% Transcutol as the penetration enhancer showed 1.7-fold enhancement in flux and permeation coefficient as compared to
marketed cream and ointment formulation. In vivo antiviral studies were performed in female Balb/c mice against induced herpes simplex virus I infection. A single application
of microemulsion formulation containing 2.5% Transcutol given 24 h post-injection resulted in complete suppression of development
of herpetic skin lesions. 相似文献
20.
Surmounting the constraints of limited solubilization efficiency and prime requisite of antioxidant for conventional lipid
formulations, the research work explores an edge over formulation utilizing potential applicability of rice germ oil (RGO)
as a multifunctional excipient. Self-microemulsifying drug delivery system (SMEDDS) of tacrolimus (TAC) was formulated with
RGO, an indigenous source of gamma-oryzanol. Being the same biological source, RGO and rice bran oil (RBO) were compared and
it was found that RGO have more solubilization potential for TAC (2.2-fold) as well as higher antioxidant activity (8.06-fold)
than the RBO. TAC-SMEDDS was prepared using RGO/Capmul PG8 (2:3) as an oil phase, Cremophore EL as a surfactant, and Transcutol
P as a cosurfactant. The approximate particle size of TAC-SMEDDS was found to be 38 nm by dynamic light scattering and 12 nm
by small angle neutron scattering. The in vitro dissolution studies showed complete and rapid drug release in 30 min compared to a plain drug (<5%) and marketed capsule
(<50%). AUC and C
max were found to be 45.05 ± 15.64 ng h/ml and 3.91 ± 1.2 ng/ml for TAC-SMEDDS, 12.59 ± 5.54 ng h/ml and 0.48 ± 0.12 ng/ml for
plain TAC, and 30.23 ± 10.34 ng h/ml and 2.31 ± 0.68 ng/ml for marketed formulation, respectively. The improved pharmacokinetic
profile of TAC-SMEDDS is correlating to the dissolution results. Thus, gamma-oryzanol-enriched RGO acts as a potential multifunctional
excipient for lipid formulations. 相似文献