Influence of liposphere preparation on butyl-methoxydibenzoylmethane photostability

The incorporation of butyl-methoxydibenzoylmethane (BMDBM), one of the most efficient and frequently used UV-A blockers, into lipospheres was examined in order to decrease the light-induced sunscreen degradation. Lipospheres, obtained by the melt technique and using tristearin as the lipid material and hydrogenated phosphatidylcholine as the emulsifier, showed proper features in terms of size (10-40 microm), BMDBM loading level (21.63% +/- 0.90%, w/w) and physical state. Photolysis studies, involving irradiation of lipospheres with simulated sunlight before and after their introduction in emulsion formulations, demonstrated a relevant enhancement of the encapsulated sunscreen photostability in comparison with unencapsulated BMDBM.

Incorporation of the sunscreen agent, octyl methoxycinnamate in a cellulosic fabric grafted with β-cyclodextrin

The aim of the study was to investigate the incorporation of the sunscreen agent, octyl methoxycinnamate into cyclodextrin cavities covalently bound to cloth fibres. Tencel, a cellulosic fabric, was grafted with beta-cyclodextrin molecules through reaction with monochlorotriazinyl-beta-cyclodextrin (beta-CDMCT). The finished and untreated textiles were soaked in water-methanol mixtures containing 2% (v/v) of sunscreen agent and subsequently subjected to several washing cycles. The unmodified and modified fabrics were characterized by UV spectrophotometry and thermogravimetric analysis. The level of octyl methoxycinnamate entrapped in the Tencel tissue was determined by high-performance liquid chromatography and was found to be much higher (0.0203%, w/w) for the textile functionalised with beta-CDMCT compared to the unmodified fabric (0.0025%, w/w). In addition, spectrophotometric assessment of UV transmission through the fabric samples using the Transpore test showed that the in vitro sun protection factor of the textile support was markedly enhanced (3.2-fold increase) by impregnation with octyl methoxycinnamate of the beta-CDMCT grafted textile. Hence, even after repeated washings, the beta-CD finished fabric exhibits higher sunscreen agent retention and photoprotective properties than the unmodified textile material.

Influence of complexation with cyclodextrins on photo-induced free radical production by the common sunscreen agents octyl-dimethylaminobenzoate and octyl-methoxycinnamate

The influence of complexation with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) or beta-cyclodextrin (beta-CD) on the photo-induced production of free radicals by the sunscreen agents octyl-dimethylaminobenzoate (ODAB), oxybenzone (OB) and octyl-methoxycinnamate (OMC) was investigated. The formation of radical species during irradiation was detected by spin-trapping electron paramagnetic resonance (EPR) spectroscopy. 2,2,6,6-tetramethylpiperidine-1-oxyl, nitroxide radical (TEMPO) and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) were used a spin-traps. Following the 4-h illumination with simulated sunlight, OB did not generate radicals. On the other hand, photoexcitation of solutions containing ODAB or OMC produced a marked decrease (>40%) of the TEMPO signal intensity, demonstrating the formation of carbon-centred radicals. In addition, the results obtained on irradiation of ODAB solutions containing DMPO as spin-trap indicated the generation of oxygen-centred radicals. Complexation of ODAB with HP-beta-CD and OMC with beta-CD markedly inhibited (>64%) the formation of free radicals generated by the sunscreens on exposure to simulated sunlight. Therefore, inclusion of ODAB and OMC into the cyclodextrin cavities minimizes their photosensitising potential.

Enhancement of melatonin photostability by encapsulation in lipospheres

The effect of lipid microparticle carrier systems on the light-induced degradation of melatonin was investigated. Microspheres loaded with melatonin were prepared using tristearin or tripalmitin as the lipid material and hydrogenated phosphatidylcholine or polysorbate 60 as the emulsifier. The obtained lipid microspheres were characterized by scanning-electron microscopy and differential scanning calorimetry. Free or microencapsulated melatonin was incorporated in a model cream formulation (oil-in-water emulsion) and irradiated with a solar simulator. The extent of photodegradation was measured by high-performance liquid chromatography. The photolysis experiments demonstrated that the light-induced decomposition of melatonin was markedly decreased by encapsulation into lipid microspheres based on tristearin and phosphatidylcholine (the extent of degradation was 19.6% for unencapsulated melatonin compared to 5.6% for the melatonin-loaded microparticles). Therefore, incorporation in lipid microparticles can be considered an effective system to enhance the photostability of melatonin.

Hypo-excitability of cortical areas in patients affected by Friedreich ataxia: A TMS study

The aim of the study was to explore excitability of a motor and a non-motor (visual) area in patients affected by Friedreich ataxia and to correlate neurophysiological data with clinical parameters. Seven patients (3M/4F) and ten healthy controls (5M/5F) participated in the study. The hot-spot for activation of right abductor pollicis brevis was checked by means of a figure-of-eight coil and the motor threshold (MT) on this point was recorded. The phosphene threshold (PT) was measured by means of a focal coil over the occipital cortex as the lower intensity of magnetic stimulation able to induce the perception of phosphenes. The patients showed a significantly higher mean PT (p<.03) and MT values (p<.001) than controls. In all but one patient unable to perceive phosphenes (42% vs. 50% of controls), TMS at 100% intensity did not elicit motor response at rest. The difference in percentage of patients (57.1%) and controls (100%) with motor responses was nearly significant. The size of GAA1 expansion showed significant correlations with PT and MT values. The results of our study showed that FA patients had reduced cortical activation, involving both the motor and the visual cortex. The cortical involvement in these patients seems to be mainly genetically determined. The study provides the first evidence of cortical dysfunction in patients with genetically defined Friedreich ataxia.

Assay of common sunscreen agents in suncare products by high-performance liquid chromatography on a cyanopropyl-bonded silica column

A rapid high-performance liquid chromatographic method was developed for the simultaneous assay of eight of the most common sunscreen agents (octyl-methoxycinnamate, oxybenzone, butyl-methoxydibenzoylmethane, octyl-salicilate, methylbenzylidene camphor, octyl-dimethylamminobenzoate, phenylbenzimidazole sulphonic acid and octocrylene) in sun protection products. Evaluation of the influence of different stationary phases and eluents on the separation selectivity showed that optimal resolution was obtained on a cyanopropyl-silica column eluted with methanol-acetonitrile-tetrahydrofuran-aqueous acetic acid. A small adjustment of the proposed chromatographic system (reduction in the aqueous content of the mobile phase) permitted also the determination of the extremely hydrophobic UV filter, methylene bis-benzotriazolyl tetramethylbutylphenol along with three other sunscreen agents, octyl-methoxycinnamate, oxybenzone, butyl-methoxydibenzoylmethane. Recoveries of the UV filters from the spiked formulation were between 95.7 and 103.7% and the precision of the method was better than 6.1% relative standard deviation. The developed HPLC procedure is suitable for quality control and photostability analyses of commercial suncare products.

Influence of cyclodextrins on in vitro human skin absorption of the sunscreen, butyl-methoxydibenzoylmethane

The effects of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and sulfobutylether-beta-CD (SBE7-beta-CD) on in vitro human skin penetration and retention of the sunscreen agent butyl-methoxydibenzoylmethane (BM-DBM) were investigated. The interaction between the UV filter and the cyclodextrins was studied in water by phase-solubility analysis. Solid complexes were prepared by the co-evaporation method and characterized by (1)H NMR spectroscopy, thermal analysis and powder X-ray diffraction. Solutions containing BM-DBM free or complexed with cyclodextrins were applied to excised human skin in Franz diffusion cells and the amount of sunscreen permeated after 6 h into the stratum corneum, viable epidermis, dermis and receptor fluid was assessed by HPLC. As much as 14.10-16.78% of the applied dose of BM-DBM penetrated within the skin tissue. No sunscreen was detected in the dermis and in the receiver phase. The greater proportion (84.6-95.5%) of the absorbed UV filter was localized in the stratum corneum with no significant differences between uncomplexed or complexed BM-DBM. Notable levels (2.29% of the applied dose) of the sunscreen agent accumulated in the epidermis from the preparation containing free BM-DBM. The epidermal concentration of the UV filter was markedly reduced (0.66% of the applied dose) by complexation with SBE7-beta-CD, whereas HP-beta-CD had no effect. The decreased BM-DBM retention in the epidermal region achieved by SBE7-beta-CD limits direct contact of the sunscreen and of its reactive photolytic products with the skin viable tissues.

Ursodeoxycholic acid does not affect ethinylestradiol bioavailability in women taking oral contraceptives

OBJECTIVE

Contraception is recommended for female patients during ursodeoxycholic acid (UDCA) treatment for the potential teratogenic effect of this bile acid, and the aim of our study was to determine whether this treatment affects the bioavailability of ethinylestradiol (EE2).

METHODS

In this double-blind, randomised study, we measured EE2 pharmacokinetics in eight healthy volunteers randomly allocated to receive oral contraceptive (30 microg EE2 and 75 microg gestodene) plus either UDCA (8-10 mg/kg per day) or placebo for 21 days during the first of three consecutive menstrual cycles. After a washout period during the second cycle, the subjects received the alternative treatment during the third menstrual cycle. Serum EE2 and UDCA were measured using radioimmunoassay and gas chromatography-mass spectrometry, respectively.

RESULTS

The profile for serum EE2 concentration was similar during UDCA (mean maximum serum concentration 177 pg/ml, SEM 59) and during placebo treatment (153 pg/ml, SEM 62), and mean area under the curve (AUC) was 1374 pg/h per ml (SEM 580) and 1320 pg/h per ml (SEM 551) during the two regimens, respectively. The point estimates and 90% confidence intervals of UDCA/placebo ratios for EE2 AUC and for maximum serum concentration were 1.1 (0.8-1.5) and 1.2 (1.0-1.4), respectively. Mean serum triglycerides concentration increased from 58.3 mg/dl (SEM 6.8) at enrolment to 91.4 mg/dl (SEM 10.7) during placebo (P < 0.01) and to 88.6 mg/dl (SEM 13.7) during UDCA treatment (P < 0.05). During UDCA treatment, serum enrichment with this bile acid and with the metabolite iso-UDCA was 29% (16%) and 3% (2%), respectively.

CONCLUSION

Co-administration with UDCA does not affect the bioavailability of EE2 in healthy volunteers, indicating that contraceptive efficacy is not affected.

Complexation of the sunscreen agent, phenylbenzimidazole sulphonic acid with cyclodextrins: effect on stability and photo-induced free radical formation

The interaction between the sunscreen agent, phenylbenzimidazole sulphonic acid (PBSA) and hydrophilic alpha-, beta-, and gamma-cyclodextrin derivatives was investigated under acidic conditions (pH 4.0) by phase-solubility analysis. Among the available cyclodextrins, hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and random methyl-beta-cyclodextrin (RM-beta-CD) had the greatest solubilizing activity. The complexation of the sunscreen agent with HP-beta-CD and RM-beta-CD was confirmed by nuclear magnetic resonance spectroscopy. Solid-phase characterization of the PBSA/cyclodextrin systems by X-ray diffractometry defined the most appropriate method (co-evaporation) and cyclodextrin concentration (10-fold molar excess) for the preparation of a stable complexed form of PBSA. Long-term stability studies demonstrated that the decrease of the sunscreen level in emulsion preparations (pH 4.0) was almost completely suppressed by HP-beta-CD, RM-beta-CD being less effective. Moreover, the irradiation-induced decomposition of PBSA in the emulsion vehicle was markedly reduced by complexation with HP-beta-CD (the extent of degradation was 3.9% for the complex compared to 9.1% for uncomplexed PBSA), whereas RM-beta-CD had no significant influence. In addition, electron paramagnetic resonance (EPR) spin-trapping studies showed that the inclusion of the sunscreen agent into the HP-beta-CD cavity completely inhibited the formation of free-radicals generated by PBSA on exposure to simulated sunlight, thereby suppressing its photosensitising potential.

Influence of cyclodextrin complexation on the photodegradation and antioxidant activity of alpha-tocopherol

The influence of complexation with beta-cyclodextrin (beta-CD), hydroxypropyl-beta-cyclodextrin (HP-beta-CD) or hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) on the antioxidant activity and light-induced decomposition of vitamin E (alpha-tocopherol) was investigated. The interaction of the vitamin with the cyclodextrins was ascertained by nuclear magnetic resonance spectroscopy. The photodegradation of alpha-tocopherol was examined in emulsion vehicles and was not significantly influenced by complexation with beta-CD (the extent of decomposition was 39.9% for the beta-CD complex compared to 47.2% for the free vitamin) whereas HP-beta-CD and HP-gamma-CD enhanced the light-induced decomposition of alpha-tocopherol (the loss of the vitamin reached 64.6% for the HP-beta-CD complex and 65.8% for the HP-gamma-CD complex). On the other hand, accelerated stability studies indicated that the degradation of non-irradiated alpha-tocopherol was reduced by complexation with HP-beta-CD or HP-gamma-CD. The radical scavenging activity of alpha-tocopherol was evaluated in vitro using the xanthine/xanthine oxidase enzymatic system. No significant differences were observed between the free form of the vitamin and its complexes with beta-CD, HP-beta-CD or HP-gamma-CD. Therefore, complexation of alpha-tocopherol with these cyclodextrins does not interfere with the vitamin antioxidant activity.

1 Hz rTMS enhances extrastriate cortex activity in migraine: Evidence of a reduced inhibition?

We recently reported a paradoxical facilitatory effect of 1 Hz repetitive TMS (rTMS) on the primary visual cortex in migraine possibly due to the failure of inhibitory circuits, unable to be upregulated by low frequency rTMS. To investigate if inhibitory circuit dysfunction extends beyond striate cortex in migraine with aura, we studied the effects of 1 Hz rTMS over the right extrastriate cortex on perception of illusory contours in these patients. Low-frequency rTMS enhanced activity of extrastriate cortex in migraineurs, speeding up reaction times on illusory contour perception. This finding supports the view of a failure of inhibitory circuits also involving the extrastriate cortex in migraine with aura.

Intestinal absorption of the bile acid analogue 75Se-homocholic acid-taurine is increased in primary biliary cirrhosis, and reverts to normal during ursodeoxycholic acid administration

BACKGROUND

Whether ileal absorption of bile acid is up or downregulated in chronic cholestasis is still debated, and most evidence has come from animal studies.

AIMS

To compare ileal bile acid absorption in patients with primary biliary cirrhosis (PBC) and in healthy control subjects, and to assess the effect of ursodeoxycholic acid (UDCA).

PATIENTS

We studied 14 PBC patients before and during (n=11) UDCA administration, 14 healthy control subjects, and 14 Crohn's disease patients (as disease controls).

METHODS

We used cholescintigraphy to measure retention in the enterohepatic circulation over five successive days of the bile acid analogue (75)Se-homocholic acid-taurine ((75)SeHCAT) as an index of ileal bile acid absorption. Results were expressed as (75)SeHCAT fractional turnover rate (FTR) and t(1/2)12.

RESULTS

(75)SeHCAT FTR was 0.19 (0.11)/day, 0.34 (0.11)/day (p<0.001), and 0.83 (0.32)/day in PBC patients, healthy controls (p<0.0001), and Crohn's patients (p<0.001), respectively, which increased to 0.36 (0.16)/day in PBC patients during UDCA treatment (p<0.005). (75)SeHCAT t(1/2)12 was 4.8 (2.1) days in PBC patients, 2.2 (0.5) days (p<0.001) in healthy controls, and 1.0 (0.5) days (p<0.001) in Crohn's disease patients. (75)SeHCAT t(1/2)12 decreased to 2.2 (0.93) days (p< 0.001) in PBC patients during UDCA treatment.

CONCLUSIONS

Our results support the concept that ileal bile acid absorption is upregulated in PBC patients, and that this effect may contribute towards damaging the cholestatic liver. This upregulation of bile acid absorption is abolished by UDCA.

Illusory contours and specific regions of human extrastriate cortex: evidence from rTMS

Functional magnetic resonance imaging studies showed that perception of illusory contours is associated with extrastriate cortex activation prevailing on the right side. 1 Hz repetitive transcranial magnetic stimulation (rTMS) is able to induce lasting inhibition of cortical activity. The objective of the study was to investigate the role of extrastriate cortex in illusory contour perception inducing 1 Hz rTMS interference in healthy subjects. Eight healthy subjects underwent 1 Hz rTMS (600 pulses) through a figure-of-eight coil over right and left occipital cortex (O1 and O2 of 10/20 EEG system); sham magnetic stimulation on the same sites and right motor cortex rTMS (in three subjects) were given as control. Subjects performed a computerized task requiring perception of illusory and real contours of Kanizsa squares in baseline and after rTMS. After stimulus presentation the subject made a forced-choice decision about the regularity or irregularity of stimulus contour, by hitting as fast as possible one of two keys on the computer keyboard. Reaction times (RT) were measured. Right occipital stimulation significantly increased RT for illusory contour perception (vs. baseline, P < 0.05). No significant RT changes were observed in the other experimental conditions with respect to the baseline condition. It is concluded that 1Hz rTMS of right extrastriate cortex can disrupt perception of illusory contours and the effect appears to be side-specific, being evident only after right occipital stimulation. This study supports the critical role of right extrastriate cortex in illusory contour perception.

Migration of antioxidant additives from various polyolefinic plastics into oleaginous vehicles

The migration of the antioxidant additives pentaerythrityl tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1010) and tris(2,4-di-tert-butylphenyl)phosphite (Irgafos 168) from polyolefinic packaging into oily vehicles was investigated. The polyolefins included in the study were from the following classes: isotactic polypropylene homopolymer (PP), ethylene-co-propylene random copolymer (RACO), ethylene-propylene heterophasic copolymer and ethylene-propylene amorphous copolymer blend (EP) and high-density polyethylene (HDPE). Each polymer was additioned with Irganox 1010 (0.15%, w/w) and Irgafos 168 (0.15%, w/w) and processed into blown bottles. To study the antioxidant release process, plastic sheets were cut from the bottles and dipped for various time intervals into a mixture of five oils (caprylic/capric triglyceride, cyclomethicone, dicaprylyl ether, isohexadecane and C(12-15) alkyl benzoate) representative of lipophilic excipients used in pharmaceutical and cosmetic formulations. After exposure to the oil medium, the non-migrated Irganox 1010 and Irgafos 168 were recovered from the polymeric matrices using microwave-assisted extraction with ethyl acetate-hexane and assayed by HPLC. The leaching of the two antioxidants varied remarkably depending on the polyolefin crystallinity and structure. The amount of Irganox 1010 transferred into the contact medium at 25 degrees C decreased in the order EP>RACO>PP>HDPE. The same polyolefin ranking was observed in the case of Irgafos 168, except for PP and HDPE which exhibited similar depletion of this additive. Migration of Irgafos 168 was greater than that of Irganox 1010 and the release of both antioxidants increased at higher temperature (50 degrees C). The obtained data are useful for the selection of polyolefinic matrices as raw-materials for the production of pharmaceutical and cosmetic containers.

Determination of undecylenic and sorbic acids in cosmetic preparations by high performance liquid chromatography with electrochemical detection

A highly sensitive and selective method for the determination of sorbic (SA) and undecylenic acid (UA) in cosmetic formulations by a high performance liquid chromatography method with electrochemical detection (ECD) is described. The pre-column derivatizations of SA and UA and the internal standard (cyclohexanoic acid (cHA)) were carried out using 1-(2,5-dihydroxyphenyl)-2-bromoethanone (2,5-DBE) as an electroactive labeling reagent previously synthesized in our lab. The resulting electroactive esters were separated by isocratic elution of a 5 micrometer Hypersil CN column with acetonitrile-acetate buffer eluent. The compounds were detected by a porous graphite electrode set at an oxidation potential of +0.45 V. The analytical method developed in this study is suitable for quality control assays of complex cosmetic formulations containing sorbic and/or UA.

Comparative studies of the influence of cyclodextrins on the stability of the sunscreen agent, 2-ethylhexyl-p-methoxycinnamate

The effects of beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the base-catalyzed degradation and light-induced decomposition of the sunscreen agent, trans-2-ethylhexyl-p-methoxycinnamate (trans-EHMC) were investigated. Reversed-phase liquid chromatography was used to study the interaction between natural and modified cyclodextrins, added to the mobile phase, and the sunscreen. Among the available cyclodextrins (beta-CD, HP-beta-CD, hydroxypropyl-alpha-cyclodextrin and hydroxypropyl-gamma-cyclodextrin), only HP-beta-CD and beta-CD produced a significant decrease in the chromatographic retention of trans-EHMC. The complexation of the sunscreen agent with HP-beta-CD and beta-CD was confirmed by thermal analysis and nuclear magnetic resonance spectroscopy. beta-CD depressed the decomposition of trans-EHMC in alkaline solutions more effectively than HP-beta-CD. Moreover, the irradiation-induced degradation of the sunscreen agent in emulsion vehicles was reduced by complexation with beta-CD (the extent of degradation was 26.1% for the complex compared to 35.8% for free trans-EHMC) whereas HP-beta-CD had no significant effect. Therefore, the complex of beta-CD with trans-EHMC enhances the chemical- and photo-stability of the sunscreen agent. Moreover, it limits adverse interactions of the UV filter with other formulation ingredients.

Influence of hydroxypropyl-beta-cyclodextrin on photo-induced free radical production by the sunscreen agent, butyl-methoxydibenzoylmethane

The aim of the study was to investigate the effect of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the photo-induced production of free radicals by the sunscreen agent, butyl-methoxydibenzoylmethane (BMDBM). Spin-trapping/electron paramagnetic resonance spectroscopy was used to evaluate the formation of radicals and the extent of BMDBM photodegradation was measured by high-performance liquid chromatography. The stable 2,2,6,6-tetramethylpiperidine-1-oxyl, nitroxide radical (TEMPO) was used as spin-trap. Any free radicals generated during irradiation of the sunscreen agent will couple with the TEMPO radicals giving diamagnetic species and thus a decrease of the signal intensity in the electron paramagnetic resonance spectrum. Following 2-h illumination with simulated sunlight, the solution containing free BMDBM exhibited a 93.9% decrease of the intensity of the TEMPO signal. Under the same irradiation conditions, only a 12.2% reduction of the TEMPO concentration was measured in the sample containing BMDBM complexed with HP-beta-CD. Moreover, the decrease of the spin-trap level observed for the HP-beta-CD/BMDBM complex was not significantly different from that produced when solutions containing TEMPO only or TEMPO in the presence of HP-beta-CD alone were subjected to irradiation. In addition, the photodegradation of the sunscreen agent was reduced by complexation with HP-beta-CD (the extent of degradation was 27.6% for the complex compared with 63.1% for free BMDBM). The results obtained indicate that the free radicals generated by BMDBM when exposed to simulated sunlight are effectively scavenged by inclusion complexation of the sunscreen agent with HP-beta-CD.

Effect of nanoparticle encapsulation on the photostability of the sunscreen agent, 2-ethylhexyl-p-methoxycinnamate

The aim of this study was to investigate the influence of nanoparticle-based systems on the light-induced decomposition of the sunscreen agent, trans-2-ethylhexyl-p-methoxycinnamate (trans-EHMC). Ethylcellulose (EC) and poly-D,L-lactide-co-glycolide (PLGA) were used as biocompatible polymers for the preparation of the particulate systems. The "salting out" method was used for nanoparticle preparation and several variables were evaluated in order to optimize product characteristics. The photodegradation of the sunscreen agent in emulsion vehicles was reduced by encapsulation into the PLGA nanoparticles (the extent of degradation was 35.3% for the sunscreen-loaded nanoparticles compared to 52.3% for free trans-EHMC) whereas the EC nanoparticle system had no significant effect. Therefore, PLGA nanoparticles loaded with trans-EHMC improve the photostability of the sunscreen agent.

Rapid techniques for the extraction of vitamin E isomers from Amaranthus caudatus seeds: ultrasonic and supercritical fluid extraction

Supercritical fluid extraction (SFE) of seeds of Amaranthus caudatus (Amaranthaceae) and the use of ultrasound as a co-adjuvant in the extraction process were compared with methods traditionally used in the extraction of tocopherols and fatty acids. The use of readily available ultrasound equipment as an adjunct to the classical methods employed for the extraction of tocols provided qualitatively acceptable results more rapidly and more economically. SFE gave quantitatively better yields in shorter times, with solvent-free extracts obtained under conditions that minimised the degradation of thermolabile components. No significant variations were observed in the profile of the fatty acids extracted from amaranth oil by SFE or other methods, thus confirming the qualitative comparability of the faster supercritical extraction with the more time-consuming classical techniques even when processed with the aid of ultrasound.

Wild Amaranthus caudatus seed oil, a nutraceutical resource from Ecuadorian flora

Seed oil of wild Amaranthus caudatus from Ecuador was analyzed for determining the tocopherol, fatty acid, and sterol contents. The data obtained were compared with the analogous chemical profile of seed oil of Italian A. caudatus with the objective of evaluating the nutraceutical and alimentary potential of the Ecuadorian matrix. Supercritical fluid and ultrasound-enhanced extractions were performed on both matrices. Qualitative and quantitative determinations of tocopherols were performed by HPLC, whereas GC and GC-MS were used to determine the fatty acid composition and sterols, respectively. Supercritical fluid extraction at 400 atm was the most efficient extraction method in terms of both total yield extract and tocopherol yield. Seeds of Ecuadorian of A. caudatus contained higher levels of tocopherols than Italian samples, whereas the fatty acid composition and sterol content were similar. From the obtained results it can be suggested that seed oil of wild Ecuadorian A. caudatus can prove to be an effective nutraceutical and alimentary resource and a valid alternative to the European varieties.

Phacovitrectomy without prone posture for full thickness macular holes

AIMS

To investigate the role of phacovitrectomy surgery without prone posture for stage 2 and 3 macular holes.

METHODS

A pilot study was performed on 20 patients (20 eyes) having phacoemulsification lens removal and vitrectomy surgery with 20% C(2)F(6) tamponade. Patients were advised to avoid lying on their backs for 10 days following surgery but no other posturing instructions were given. Closure rates and improvement in visual acuity were compared with a group of historical controls in whom phacovitrectomy with gas tamponade and face down posturing was performed.

RESULTS

Anatomical hole closure was noted in 18 of the 20 eyes (90%). 19 eyes (95%) showed an improvement of at least 0.3 logMAR units. This compares favourably with the postured group in which anatomical hole closure was noted in 11 of 13 eyes (85%) and nine of 13 eyes (69%) showed an improvement of at least 0.3 logMAR units.

CONCLUSION

Combined surgery facilitates the use of a large gas bubble. Sufficient tamponade of the hole occurs for closure without prone posturing. Combined surgery prevents patients posturing and returning for cataract surgery.