• Clean Technology
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• v.12 no.4
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• pp.205-210
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• 2006

In this study, polystyrene hollow microspheres were prepared via optimized purifying steps for the reuse of waste polystyrene. PS/PVA double layered hollow microspheres were prepared using the multiple emulsion ($W_1/O/W_2$) method with recycled polystyrene. The sonication treatment at the first stage of $W_1/O$ emulsion formation was very important factor of control of particle size and its distribution. When sonication was treated for 20 seconds, the average particle size and distribution were $1.35{\mu}m$ and $0.8{\mu}m{\sim}2.8{\mu}m$, respectively. The double layered hollow microspheres that have smaller and uniformed particle size distribution were manufactured when gelatin or Tween 80 was used as surfactants in the $W_2$ phase.

• Clean Technology
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• v.14 no.4
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• pp.256-264
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• 2008

In this study, using PBAST (poly(butylene adipate-co-succinate-co-terephthalate)) which was eco-friendly biodegradable aliphatic polyester, PBAST/PVA (poly(vinyl alcohol)) double-layered hollow microspheres were prepared with the water/oil/water multiple emulsion ($W_1/O/W_2$) method. The double-layered hollow microspheres were manufactured with the yield of 30.92% when the concentration of polymer PBAST in organic phase was 5 wt%, the concentration of PVA in inner aqueous phase was 5 wt%, the volume ratio of $W_1/O$ emulsion to outer aqueous phase was 1:4.5, and when co-surfactants that had large gap in HLB (hydrophile-lipophile balance) value were used. The bulk density of prepared hollow microsphere was 0.180 g/ml and particle size was $1.5{\sim}3\;{\mu}m$.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.511-520
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• 2000

Various bupivacaine-loaded microspheres were prepared from poly (d,l-lactide) (PLA) or poly (d,l-lactic-co-glycolide) (PLGA) by a solvent evaporation method for the sustained release of drug. PLA and PLGA microspheres were prepared by w/o/w and w/o/o multiple emulsion solvent evaporation, respectively. The effects of process conditions such as emulsification speed, emulsifier type, emulsifier concentration and internal/external phase ratio on the characteristics of microspheres were investigated. The prepared microspheres were characterized for their drug loading, size distribution, surface morphology and release kinetics. Drug loading efficiency was higher in the microspheres prepared by w/o/o multiple emulsion than that by w/o/w multiple emulsion method, because the solubility of bupivacaine HCI was decreased in oil phase compared with water phase. The prepared microspheres had an average diameter between 1 and $2\;{\mu}M$ in all conditions of two methods. In morphology studies the PLA microspheres showed an irregular shape and smooth surface, but PLGA microspheres had a spherical shape and smooth surface. The release pattern of the drug from microspheres was evaluated on the basis of the burst effect and the extent of the release after 24h. The in vitro release of bupivacaine HCl from microspheres showed a large initial burst release and $60{\sim}80%$ release within one day in all conditions of two methods. The extents of the burst release against PLA and PLGA microspheres were $30{\sim}50%$ and $50{\sim}80%$ within 20min, respectively. This burst release seems to be due to the smaller size of microspheres and the solubility of drug in water.

• Journal of Life Science
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• v.20 no.8
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• pp.1241-1248
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• 2010

The solvent extracts of Nelumbo nucifera G. were investigated for antioxidant activities, whitening and anti-wrinkle effects to apply as a functional ingredient in cosmetic products. For their industrial application, the cosmetic products were also prepared with advanced formulation techniques such as W/O/W multiple emulsion. Total phenolic and flavonoids contents increased in Nelumbo nucifera G.-Leaf (NN-L). The electron donating ability of Nelumbo nucifera G.-Flower (NN-F) or Nelumbo nucifera G.-Leaf (NN-L) extracts were above 85% at a concentration of 500 ppm. The superoxide dismutase (SOD)-like activity of Nelumbo nucifera G. (NN-L) extracts was about 60% at a concentration of 1,000 ppm. The xanthine oxidase inhibitory effect of NN-L extract was higher than that of NN-F and NN-S extracts. The tyrosinase inhibitory effect, which is related to skin-whitening, was 36% in NN-F at 1,000 ppm. For anti-wrinkle effect, the elastase inhibition activity of NN-L was about 30% at 1,000 ppm. The results of stability test showed that W/O/W multiple emulsion (ME) containing Nelumbo nucifera G. extracts. The electron donating ability of the ME containing NN-F and NN-L were about 60% at a concentration of 100 ppm. The superoxide dismutase (SOD)-like activity of the ME containing NN-L was 30% at 1,000 ppm. The tyrosinase inhibitory effect, which is related to skin-whitening, was 34% in the ME containing NN-F at 1,000 ppm. In anti-wrinkle effect, the elastase inhibition activity of the ME containing NN-L was about 55% at 1,000 ppm.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.4 s.59
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• pp.209-217
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• 2006

Emulsion is a dispersion system among liquids which are not miscible together. There are numerous cosmetic raw materials which have different physicochemical properties. Therefore, emulsion technology is very useful in cosmetics. With the development of emulsifier, several emulsification technologies have been developed. Since HLB method by Griffin in 1950's, PIT method, gel method, and D-phase methods, etc, have been developed. Recently, the application of natural emulsifier and polymeric emulsifier increases in cosmetics in order to achieve enhanced safety and biocompatibility. Besides nano-emulsion, multiple-emulsion, liquid crystal emulsion, and Pickering emulsion have been developed and applied as means of differentiating appearance and texture of products and achieving enhanced delivery of active ingredients. Meanwhile, the application studies of nano-dispersed structural system such as liposome or cubosome are on progress. Liposome is a bi- or multi-lamella layer dispersion system composed of amhiphilic molecules - phospholipids which are main components of plasma membrane. Cubosome also is a nano-sized dispersion system composed of a specific molecule like glyceryl monoloeate derived from natural products. And it has a cubic bicontinuous structure in water due to its unique molecular structure. Incorporating compounds (active materials) into such nano-particles can increase biocompatibility and delivery efficiency of target compounds. Manufacturing process and application of cosmetic emulsions and nano-particles are briefly introduced in this paper.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.385-390
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• 2000

To demonstrate the effect of formulation conditions on the controlled release of protein from poly(lactide-co-glycolide) (PLGA) microspheres for use as a parenteral drug carrier, ovalbumin (OVA) microspheres were prepared using the W/O/W multiple emulsion solvent evaporation and extraction method. Methylene chloride or ethyl acetate was applied as an organic phase and poly(vinyl alcohol) as a secondary emulsion stabilizer. Low loading efficiencies of less than 20％ were observed and the in vitro release of OVA showed a burst effect in all batches of different microspheres, followed by a gradual release over the next 6 weeks. Formulation processes affected the size and morphology, drug content, and the controlled release of OVA from PLGA microspheres.

• Journal of Pharmacopuncture
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• v.22 no.3
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• pp.147-153
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• 2019

Objectives: Many studies have been reported the efficacy of intravenous lipid emulsion (ILE) as an antidote on acute lipophilic drug toxicity. Clozapine, highly lipophilic dibenzodiazepine neuroleptics, is an important medication in the schizophrenia therapy regimen. Acute intoxication with antipsychotics is one of the main reasons for the referral of poisoned patients to the hospital. We expected that ILE could be used for the therapy of acute clozapine intoxicated patients. Methods: We used two groups of consisting of six male rats. Both groups received a toxic dose of clozapine (40 mg/kg) intravenously, via the tail vein. After 15 minutes, they were treated with intravenous infusion of 18.6 mg/kg normal saline (NS group), or 18.6 mg/kg ILE 20% (ILE group). We evaluated blood pressure (BP) and heart rate by power lab apparatus through the tail artery, ataxia by a rat rotary circle, seizure scores and death in multiple times after starting clozapine administration. For biochemical and pathological evaluations the samples of tissue and blood were taken. Results: Our results demonstrated that ILE 20% could return hypotension-induced clozapine better than normal saline. Furthermore, ataxia and seizure have rectified more rapidly and deaths reduced. Clozapine administration causes pancreatitis and lung injury but fat emulsion did not show an optimal effect on tissue damages caused by clozapine toxicity. Conclusion: In conclusion, ILE can remove toxic signs of clozapine same as other lipophilic medicines, however, clinical uses of ILE for this intention requires more appraisement to determine the precise implication and safety.

• Biomedical Science Letters
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• v.12 no.3
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• pp.177-183
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• 2006

To demonstrate the effect of formulation conditions and evaluations of structural integrity from ovalbumin containing poly lactide glycolide copolymer (PLGA) microspheres for Vaccine delivery, OVA microspheres were prepared by a W/O/W multiple emulsion solvent extraction technique. Dichloromethan (DCM) and Ethyl acetate (EA) were applied as an organic phase and poly vinyl alcohol (PVA) as a secondary emulsion stabilizer. Microspheres were characterized for particle size, morphology (optical microscopy and Scanning Electron Microscope (SEM)). Protein denaturation was evaluated by size exclusion chromatography (SEC), SDS-PAGE and isoelectric focusing (IEF). Residual organic solvent was estimated by gas chromatography (GC) and differential scanning calorimetry (DSC). Optical photomicrograph and SEM revealed that micro spheres were typically spherical but various morphologies were observed. Mean particle size $(d_{vs})$ of microspheres were in the range of $3{\sim}50{\mu}m$. Also, The protein stability was not affected by the fonnulation process and residual organic solvent was beyond the detection below 0.1ppm. These results demonstrated that micro spheres might be a good candidate for the parenteral vaccine delivery system.

• KSBB Journal
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• v.24 no.5
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• pp.477-482
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• 2009

Anthocyanin and origomeric proanthocyanidin (OPC) fractions showing antioxidizing activity are present in grape extracts. Grape extracts are widely used in cosmetic applications as functional ingredients. The aim of our study is to isolate the antioxidant fraction from waste of grape products. The extraction was done using soxhlet apparatus. Next, the extraction was subjected for identification of antioxidants by using HPLC. Antioxidant assay was performed by using 2,2-diphenyl-picryl-hydrazyl (DPPH) and superoxide dismutase (SOD) method. Antioxidizing activity was found to be higher in grape seed extract when compared to grape skin extract. Using the extract, a novel formula with multi lamella emulsion structure has been developed and its safety and stability were confirmed by standard protocols.

• Archives of Pharmacal Research
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• v.19 no.1
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• pp.30-35
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• 1996

Poly(l-lactic acid)(PLLA) microspheres loaded with ampicillin sodium (AMP-Na_, .betha.-lactam antibiotic, were prepared by a w/o/w multiple emulsion-solvent evaporation method. The amounts of each component in three phases (inner water phase, organic phase, and outer water phase) wre carefully examined in the preparation of PLLA microspheres. The stirring rate, another preparation parameter, was also investigated for study on the effect of mechanical stress on the drug loading and morphology of PLLA microspheres. Most of the preparation parameters had a great influence on the drug loading, surface morphology and size distribution of PLLA microspheres. PLLA microspheres with 15.89 w/w% drug loading were subjected to the in vitro release experimet. The release of ampicillin sodium was constant at a rate of 1.68 $mug/ml/day$ per 1 mg of microspheres for 18 days initial burst effect.