Physicochemical characterization of rutaecarpine-loaded microemulsion system

To develop an o/w microemulsion system containing poorly water-soluble rutaecarpine, the solubility of rutaecarpine in water, ethanol, various oils, and surfactants were investigated. Among the surfactants and oils tested, Tween 20/PEG 400 and castor oil were chosen as the surfactant system and oil phase of the microemulsion, as rutaecarpine was most soluble in them, respectively. Pseudoternary phase diagrams were constructed to obtain the concentration range of oil, surfactant, and cosurfactant for microemulsion formation, and the stability test of rutaecarpine delivered by microemulsion formation was then evaluated. Pseudoternary phase diagrams show that the areas of microemulsion appeared at those with 0-20% Smix (PEG 400/Tween80 = 60/40), 64-81% water, and 10-20% oil. The rutaecarpine (300 µg/g)-loaded microemulsion composed of 10.8% PEG 400, 7.2% Tween 80, 20% caster oil, and 72% water was physically and chemically stable for at least 6 months. Thus, the microemulsion system composed of castor oil, PEG 400, Tween 80, and water could be a stable dosage form for rutaecarpine.     

Short communication: in vivo evaluation of microemulsion system for oral and parenteral delivery of rutaecarpine to rats

Rutaecarpine-loaded microemulsion composed of 10.8% polyethylene glycol 400, 7.2% Tween 80, 20% caster oil, and 62% water were previously reported to be physically and chemically stable for at least 6 months. For the development of a Rutaecarpine-loaded microemulsion, here we studied the pharmacokinetic profiles of rutaecarpine after oral and intravenous administration of rutaecarpine-loaded microemulsion compared to suspension. The AUC of rutaecarpine from microemulsion after oral and intravenous administration increased about three-fold compared with that from suspension. Furthermore, the rutaecarpine-loaded microemulsion gave significantly higher AUC and Cmax than did suspension, suggesting that the oral bioavailability of rutaecarpine in this microemulsion system could be enhanced due to the enhanced solubility of rutaecarpine by microemulsion. Thus, our results indicated that the microemulsion system composed of castor oil, polyethylene glycol 400, Tween 80, and water could be a more effective oral and parenteral dosage form for rutaecarpine.     

Effect of different polysorbates on development of self-microemulsifying drug delivery systems using medium chain lipids

The primary objective of this study was to develop lipid-based self-microemulsifying drug delivery systems (SMEDDS) without using any organic cosolvents that would spontaneously form microemulsions upon dilution with water. Cosolvents were avoided to prevent possible precipitation of drug upon dilution and other stability issues. Different polysorbates, namely, Tween 20, Tween 40, Tween 60, and Tween 80, were used as surfactants, and Captex 355 EP/NF (glycerol tricaprylate/caprate) or its 1:1 mixture with Capmul MCM NF (glycerol monocaprylocaprate) were used as lipids. Captex 355-Tween-water ternary phase diagrams showed that oil-in-water microemulsions were formed only when the surfactant content was high (80–90%) and the lipid content low (10–20%). Thus, mixtures of Tweens with Captex 355 alone were not suitable to prepare SMEDDS with substantial lipid contents. However, when Captex 355 was replaced with the 1:1 mixture of Captex 355 and Capmul MCM, clear isotropic microemulsion regions in phase diagrams with sizes in the increasing order of Tween 20?相似文献   

Development and characterization of self-microemulsifying drug delivery system of tacrolimus for intravenous administration

Tacrolimus (FK 506), a poorly soluble immunosuppressant is currently formulated in nonaqueous vehicle containing hydrogenated castor oil derivative for intravenous administration. Hydrogenated castor oil derivatives are associated with acute anaphylactic reactions. This proposes to overcome the problems of poor aqueous solubility of the drug and the toxicity associated with currently used excipients by the development of a new parenterally acceptable formulation using self-microemulsifying drug delivery system (SMEDDS). Solubility of FK 506 in various oils, surfactants, and cosurfactants was determined to identify SMEDDS components. Phase diagrams were constructed at different ratios of surfactants:cosurfactant (K(m)) to determine microemulsion existence area. Influence of oily phase content, K(m), aqueous phase composition, dilution, and incorporation of drug on mean globule size of microemulsions was studied. SMEDDSs were developed using ethyl oleate as oily phase and Solutol HS 15 as surfactant. Glycofurol was used successfully as a cosurfactant. Developed SMEDDS could solubilize 0.8% (wt/wt) FK 506 and on addition to aqueous phase could form spontaneous microemulsion with mean globule size < 30 nm. The resulting microemulsion was iso-osmotic, did not show any phase separation or drug precipitation even after 24 h, and exhibited negligible hemolytic potential to red blood cells.     

The effect of component of microemulsion for transdermal delivery of nicardipine hydrochloride

Purpose: Nicardipine hydrochloride has been used widely for the treatment of angina pectoris and hypertension. Because of its extensive first pass metabolism after oral administration, the transdermal administration of nicardipine microemulsions was developed in this study. Methods: Microemulsions consisted of isopropyl myristate (IPM), surfactant mixture of Tween 80/Span 80 and/or Tween 80/Span 20, co-surfactant (ethanol) and aqueous phase. Pseudo-ternary phase diagrams were constructed using water titration method. The effect of component of microemulsion on the percutaneous absorption of drug was evaluated by in vitro permeation study. Results: The area of microemulsion isotropic region in the presence of ethanol was comparably larger in the absence of ethanol. The mean droplet size of nicardipine microemulsions ranged from 70 to 123 nm. With addition of ethanol, the droplet size became smaller. The permeation rate and extent of nicardipine microemulsion transport across rat skin was affected by the components of microemulsion. Nicardipine microemulsion had higher flux at surfactant mixture with lower hyrophile-lipophile balance (HLB) value and Tween content. Conclusions: The microemulsion consisted of 52% IPM, 35% surfactant mixture and 13% water had higher permeation rate through rat skin above 122.53±1.87 μg/cm2/h and was expected to develop a transdermal delivery system.     

Development and Characterization of Self-Microemulsifying Drug Delivery System of Tacrolimus for Intravenous Administration

Tacrolimus (FK 506), a poorly soluble immunosuppressant is currently formulated in nonaqueous vehicle containing hydrogenated castor oil derivative for intravenous administration. Hydrogenated castor oil derivatives are associated with acute anaphylactic reactions. This proposes to overcome the problems of poor aqueous solubility of the drug and the toxicity associated with currently used excipients by the development of a new parenterally acceptable formulation using self-microemulsifying drug delivery system (SMEDDS). Solubility of FK 506 in various oils, surfactants, and cosurfactants was determined to identify SMEDDS components. Phase diagrams were constructed at different ratios of surfactants: cosurfactant (K_m) to determine microemulsion existence area. Influence of oily phase content, K_m, aqueous phase composition, dilution, and incorporation of drug on mean globule size of microemulsions was studied. SMEDDSs were developed using ethyl oleate as oily phase and Solutol HS 15 as surfactant. Glycofurol was used successfully as a cosurfactant. Developed SMEDDS could solubilize 0.8% (wt/wt) FK 506 and on addition to aqueous phase could form spontaneous microemulsion with mean globule size < 30 nm. The resulting microemulsion was iso-osmotic, did not show any phase separation or drug precipitation even after 24 h, and exhibited negligible hemolytic potential to red blood cells.     

In-vitro and in-vivo comparison of T-OA microemulsions and solid dispersions based on EPDC

The goal of this study was to enhance the absorption of a new water-insoluble antitumor lead compound, T-OA (3β-hydroxyolea-12-en-28-oic acid-3, 5, 6-trimethylpyrazin-2-methyl ester). Early-stage preparation discovery concept (EPDC) was employed in this study. Based on this concept, a microemulsion system was chosen as the method of improving bioavailability. The solubility of T-OA was checked in different oils, surfactants and cosurfactants. Ternary phase diagrams were constructed to evaluate the microemulsion domain. Developed high-performance liquid chromatography method was used to determine drug content. The transparent o/w microemulsion formulation composed of oleic acid (oil), Tween 80 (surfactant), ethanol (co-surfactant) and water enhanced the solubility of T-OA up to 20?mg/mL. It was characterized in terms of appearance, content, viscosity, zeta potential, conductivity, morphology and particle size. The particle size distribution, viscosity, conductivity and zeta potential were found to be 70?nm, 15.57?MPa?s, 44.1?μS?cm^?1 and ?0.174, respectively. Oral bioavailability of T-OA microemulsion and oleic acid solution were checked by using rat model. Contrast to the solid dispersion and proto drug, the area-under-the-curve (AUC) of T-OA microemulsion and oleic acid solution were significantly enhanced. The relative bioavailability of T-OA microemulsion was found to be 5654.7%, which is 57-fold higher than the pure drug. Improved T-OA solubility in microemulsion was found sustained 48?h in dilution study. While the solid dispersion may precipitate under the gastrointestinal circumstance based on dilution results. The in-vivo and in-vitro results indicated that, compare to improve the solubility, it is more important to maintain and prolong the T-OA dissolved status, for improvement of the in-vivo absorption.     

Preparation,characterization and in vitro evaluation of microemulsion of raloxifene hydrochloride

Raloxifene hydrochloride (RLX) is a selective estrogen receptor modulator which is orally used for treatment of osteoporosis and prevention of breast cancer. The drug has low aqueous solubility and bioavailability. The aim of the present study is to formulate and characterize oil-in-water microemulsion systems for oral delivery of RLX. To enhance the drug aqueous solubility, microemulsion based on sesame oil was prepared. Sesame oil and Tween 80 were selected as the drug solvent oil and surfactant, respectively. In the first and second formulations, Edible glycerin and Span 80 were applied as co-surfactant, respectively. Pseudo-ternary phase diagrams showed that the best surfactant/co-surfactant ratios in the first and second formulations were 4:1 and 9:1, respectively. The particle size of all free drug-loaded and drug loaded samples were in the range of 31.25?±?0.3?nm and 60.9?±?0.1?nm, respectively. Electrical conductivity coefficient and refractive index of all microemulsion samples confirmed the formation of oil-in-water type of microemulsion. In vitro drug release profile showed that after 24?hours, 46% and 63% of the drug released through the first formulation in 0.1% (w/v) Tween 80 in distilled water as a release medium and phosphate buffer solution (PBS) at pH?=?5.5, respectively. These values were changed to 57% and 98% for the second formulation. Results confirmed that the proposed microemulsion system containing RLX could improve and control the drug release profile in comparison to conventional dosage form.     

Preparation,Evaluation, and NMR Characterization of Vinpocetine Microemulsion for Transdermal Delivery

A novel microemulsion was prepared to increase the solubility and the in vitro transdermal delivery of poorly water‐soluble vinpocetine. The correlation between the transdermal permeation rate and structural characteristics of vinpocetine microemulsion was investigated by pulsed field gradient nuclear magnetic resonance (PFG‐NMR). For the microemulsions, oleic acid was chosen as oil phase, PEG‐8 glyceryl caprylate/caprate (Labrasol®) as surfactant (S), purified diethylene glycol monoethyl ether (Transcutol P®) as cosurfactant (CoS), and the double‐distilled water as water phase. Pseudo‐ternary phase diagrams were constructed to obtain the concentration range of each component for the microemulsion formation. The effects of various oils and different weight ratios of surfactant to cosurfactant (S/CoS) on the solubility and permeation rate of vinpocetine were investigated. Self‐diffusion coefficients were determined by PFG‐NMR in order to investigate the influence of microemulsion composition with the equal drug concentration on their transdermal delivery. Finally, the microemulsion containing 1% vinpocetine was optimized with 4% oleic acid, 20.5% Labrasol, 20.5% Transcutol P, and 55% double‐distilled water (w/w), in which drug solubility was about 3160‐fold higher compared to that in water and the apparent permeation rate across the excised rat skin was 36.4?±?2.1 µg/cm²/h. The physicochemical properties of the optimized microemulsion were examined for the pH, viscosity, refractive index, conductivity, and particle size distribution. The microemulsion was stable after storing more than 12 months at 25°C. The irritation study showed that the optimized microemulsion was a nonirritant transdermal delivery system.     

Effects of surfactant on release characteristics of clonidine hydrochloride from ethylcellulose film

The effects of Tween 80 (polysorbate 80) and Span 80 (sorbitan monooleate) surfactants on release characteristics of clonidine hydrochloride from ethylcellulose 10 and 20 cps matrix films containing castor oil as a plasticizer were investigated. The release rates of drug from these films in water at 37°C were found to increase with the addition of surfactant, which was highest for the film prepared from ethylcellulose 20 cps with Tween 80. The experimental values of the cumulative amount of drug released were found to conform to the solution matrix model. The calculated values of the cumulative amount of clonidine hydrochloride released using the experimentally determined diffusion coefficients were also found to be in good agreement with the observed values.     

Effects of Surfactant on Release Characteristics of Clonidine Hydrochloride from Ethylcellulose Film

The effects of Tween 80 (polysorbate 80) and Span 80 (sorbitan monooleate) surfactants on release characteristics of clonidine hydrochloride from ethylcellulose 10 and 20 cps matrix films containing castor oil as a plasticizer were investigated. The release rates of drug from these films in water at 37°C were found to increase with the addition of surfactant, which was highest for the film prepared from ethylcellulose 20 cps with Tween 80. The experimental values of the cumulative amount of drug released were found to conform to the solution matrix model. The calculated values of the cumulative amount of clonidine hydrochloride released using the experimentally determined diffusion coefficients were also found to be in good agreement with the observed values.     

Preparation and in vitro evaluation of self-microemulsifying drug delivery systems containing idebenone

A new self-microemulsifying drug delivery system (SMEDDS) was developed to increase the dissolution rate, solubility, and, ultimately, bioavailability of a poorly water soluble drug, idebenone. Pseudoternary phase diagrams were used to evaluate the self-microemulsification existence area, and the release rate of idebenone was investigated. The mixtures consisting of Labrafac hydro or Labrafil 2609 (HLB values > 4) with the surfactant (Labrasol containing 80% Transcutol) and cosurfactant (Plurol oleique WL 1173) were found to be optimum formulations. Using the SMEDDS formulations of 5% to 20% of Labrafac hydro or Labrafil 2609 in combination with the surfactant/cosurfactant mixing ratio of 3, the microemulsion existence field was wider compared to the other SMEDDS formulations due to high affinity for the continuous phase. The in vitro dissolution rate of idebenone from SMEDDS was more than twofold faster compared with that of tablets. The developed SMEDDS formulation can be used as a possible alternative to traditional oral formulations of idebenone to improve its bioavailability.     

Oral bioavailability enhancement of raloxifene by developing microemulsion using D-optimal mixture design: optimization and in-vivo pharmacokinetic study

The objective of this work was to utilize a potential of microemulsion for the improvement in oral bioavailability of raloxifene hydrochloride, a BCS class-II drug with 2% bioavailability. Drug-loaded microemulsion was prepared by water titration method using Capmul MCM C8, Tween 20, and Polyethylene glycol 400 as oil, surfactant, and co-surfactant respectively. The pseudo-ternary phase diagram was constructed between oil and surfactants mixture to obtain appropriate components and their concentration ranges that result in large existence area of microemulsion. D-optimal mixture design was utilized as a statistical tool for optimization of microemulsion considering oil, S_mix, and water as independent variables with percentage transmittance and globule size as dependent variables. The optimized formulation showed 100?±?0.1% transmittance and 17.85?±?2.78?nm globule size which was identically equal with the predicted values of dependent variables given by the design expert software. The optimized microemulsion showed pronounced enhancement in release rate compared to plain drug suspension following diffusion controlled release mechanism by the Higuchi model. The formulation showed zeta potential of value ?5.88?±?1.14?mV that imparts good stability to drug loaded microemulsion dispersion. Surface morphology study with transmission electron microscope showed discrete spherical nano sized globules with smooth surface. In-vivo pharmacokinetic study of optimized microemulsion formulation in Wistar rats showed 4.29-fold enhancements in bioavailability. Stability study showed adequate results for various parameters checked up to six months. These results reveal the potential of microemulsion for significant improvement in oral bioavailability of poorly soluble raloxifene hydrochloride.     

Preparation, evaluation, and NMR characterization of vinpocetine microemulsion for transdermal delivery

A novel microemulsion was prepared to increase the solubility and the in vitro transdermal delivery of poorly water-soluble vinpocetine. The correlation between the transdermal permeation rate and structural characteristics of vinpocetine microemulsion was investigated by pulsed field gradient nuclear magnetic resonance (PFG-NMR). For the microemulsions, oleic acid was chosen as oil phase, PEG-8 glyceryl caprylate/caprate (Labrasol®) as surfactant (S), purified diethylene glycol monoethyl ether (Transcutol P®) as cosurfactant (CoS), and the double-distilled water as water phase. Pseudo-ternary phase diagrams were constructed to obtain the concentration range of each component for the microemulsion formation. The effects of various oils and different weight ratios of surfactant to cosurfactant (S/CoS) on the solubility and permeation rate of vinpocetine were investigated. Self-diffusion coefficients were determined by PFG-NMR in order to investigate the influence of microemulsion composition with the equal drug concentration on their transdermal delivery. Finally, the microemulsion containing 1% vinpocetine was optimized with 4% oleic acid, 20.5% Labrasol, 20.5% Transcutol P, and 55% double-distilled water (w/w), in which drug solubility was about 3160-fold higher compared to that in water and the apparent permeation rate across the excised rat skin was 36.4 ± 2.1 µg/cm²/h. The physicochemical properties of the optimized microemulsion were examined for the pH, viscosity, refractive index, conductivity, and particle size distribution. The microemulsion was stable after storing more than 12 months at 25°C. The irritation study showed that the optimized microemulsion was a nonirritant transdermal delivery system.     

Single non-ionic surfactant based self-nanoemulsifying drug delivery systems: formulation,characterization, cytotoxicity and permeability enhancement study

Single non-ionic surfactant based self-nanoemulsifying drug delivery system (SNEDDS) was formulated and characterised for poor water soluble drug, Atorvastatin calcium. Capmul MCM oil showing highest solubility for Atorvastatin calcium was selected as oil phase. Self-nanoemulsifying capacity of Cremophor RH 40, Cremophor EL, Tween 20, Tween 60, Tween 80 and Labrasol were tested for the selected oil. In vitro dissolution studies were performed and were characterized by t85% and dissolution efficiency (DE). Cytotoxicity of the formulations and permeation enhancement of the drug across caco-2 cell monolayer was assessed. Capmul MCM was found to be better nanoemulsified in decreasing order of Cremophor RH 40 > Cremophor EL > Tween 20 > Tween 60 > Tween 80. Values of droplet size (range 11–83 nm), polydispersity index (range 0.07–0.65); zeta potential (range ?3.97 to ?19.0) and cloud point (60–85°C) before and after drug loading proves the uniformity and stability of the formulations. SNEDDS formulated with Tween 20 surfactant showed enhanced dissolution with t85% and DE values at 10 min and 78.70, respectively. None of the formulation showed cytotoxicity at the concentration tested. Tween 20 based SNEDDS enhanced permeation of the drug as compared with pure drug across cell lines. It can be concluded that SNEDDS can be formulated by using single non-ionic surfactant system for enhance dissolution and absorption of poorly soluble drug, Atorvastatin calcium.     

Microemulsion for simultaneous transdermal delivery of benzocaine and indomethacin: in vitro and in vivo evaluation

This study investigated simultaneous transdermal delivery of indomethacin and benzocaine from microemulsion. Eucalyptus oil based microemulsion was used with Tween 80 and ethanol being employed as surfactant and cosurfactant, respectively. A microemulsion formulation comprising eucalyptus oil, polyoxyethylene sorbitan momooleate (Tween 80), ethanol and water (20:30:30:20) was selected. Indomethacin (1% w/w) and benzocaine (20% w/w) were incorporated separately or combined into this formulation before in vitro and in vivo evaluation. Application of indomethacin microemulsion enhanced the transdermal flux and reduced the lag time compared to saturated aqueous control. The same trend was evident for benzocaine microemulsion. Simultaneous application of the two drugs in microemulsion provided similar enhancement pattern. The in vivo evaluation employed the pinprick method and revealed rapid anesthesia after application of benzocaine microemulsion with the onset being 10?min and the action lasting for 50?min. For indomethacin microemulsion, the analgesic effect was recorded after 34.5?min and lasted for 70.5?min. Simultaneous application of benzocaine and indomethacin provided synergistic effect. The onset of action was achieved after 10?min and lasted for 95?min. The study highlighted the potential of microemulsion formulation in simultaneous transdermal delivery of two drugs.     

新型非离子水性聚氨酯表面活性剂的制备及性能

采用甲苯-2,4-二异氰酸酯(TDI)、蓖麻油和聚乙二醇(PEG)等为主要原料,通过逐步聚合得到一种新型非离子水性聚氨酯表面活性剂,并利用红外光谱对其结构进行了表征。实验结果表明,当蓖麻油∶TDI∶PEG-4000=1∶9∶11时,采用依次加入蓖麻油、TDI、PEG的加料方式,能够合成得到综合性能较好的非离子水性聚氨酯表面活性剂。对该表面活性剂在水相中的表面活性进行了测试,结果表明,所制得的非离子水性聚氨酯表面活性剂的临界胶束浓度约为22 g/L,水溶液的最低表面张力可达53 mN/m。     

Oral bioavailability enhancement of acyclovir by self-microemulsifying drug delivery systems (SMEDDS)

Acyclovir is a potent anti-viral agent useful in the treatment of Herpes Simplex Virus (HSV) infections. Acyclovir exerts its antiviral activity by competitive inhibition of viral DNA through selective binding of acyclovir to HSV-thymidine kinase. The main purpose of this work was to develop self-microemulsifying drug delivery system (SMEDDS) for oral bioavailability enhancement of acyclovir. Solubility of acyclovir was determined in various vehicles. SMEDDS is mixture of oils, surfactants, and co-surfactants, which are emulsified in aqueous media under conditions of gentle agitation and digestive motility that would be encountered in the gastro-intestinal (GI) tract. Pseudoternary phase diagrams were constructed to identify the efficient self-emulsifying region dilution study was also performed for optimization of formulation. SMEDDS was evaluated for its percentage transmittance, Assay of SMEDDS, phase separation study, droplet size analysis, zeta potential, electrophoretic mobility, and viscosity. The developed SMEDDS formulation contained acyclovir (50 mg), Tween 60 (60%), glycerol (30%) and sunflower oil (9%) was compared with the pure drug solution by oral administrating to male albino rats. The absorption of acyclovir from SMEDDS form resulted about 3.5 fold increase in bioavailability compared with the pure drug solution. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds such as acyclovir by oral route.     

Mixed lipid phase SMEDDS as an innovative approach to enhance resveratrol solubility

Context: Despite its promising therapeutic activities, clinical use of resveratrol (RSV) is compromised with unfavorable biopharmaceutical properties, namely low water solubility.

Objective: This work deals with improving RSV solubility and release rate through its incorporation in innovative mixed lipid phase self-microemulsifying drug delivery systems (SMEDDS).

Methods: (Pseudo)ternary diagrams were constructed for different oils and surfactant mixtures. Selected systems were further evaluated for RSV solubility, self-emulsification ability, accelerated stability, dynamic viscosity, compatibility with hard gelatin capsules and in vitro dissolution of RSV.

Results: Lipid phase composed of diverse lipid species, castor oil (long-chained triglyceride) and Capmul MCM (mixture of medium chain mono and diglycerides) allowed formulation of mixed lipid SMEDDS with lower surfactants content (60% Cremophor EL/RH 40/RH?60). Mixed lipid phase SMEDDS showed best self-emulsifying ability with regard to self-emulsifying time as well as droplet size and monodispersity of microemulsions obtained upon SMEDDS dilution with aqueous phase. Overall, incorporation of RSV in SMEDDS resulted in improved solubility (over 23-fold) and dissolution rate compared to crystalline RSV. All SMEDDS formulations were adequately viscous for filling into hard gelatin capsules (>150?mPa?s for empty SMEDDS; >400?mPa?s for RSV-loaded SMEDDS) and no leaking was observed during three months of storage.

Conclusion: The presented work indicates the promising potential of mixed lipid SMEDDS formulations for future development of SMEDDS with lower surfactant content and no added cosolvents for incorporation of RSV and other poorly soluble drugs.     

Effect of surfactants on preparation of nanoscale α-Al2O3 powders by oil-in-water microemulsion

The nanoscale α-Al₂O₃ powders have been synthesized by the O/W microemulsion system using cyclohexane as the oil phase, ultrapure water as the water phase, OP-10 and alcohol as the surfactant and co-surfactant. It has been found that the nature of surfactants played an important role to regulate the size and morphologies of the α-Al₂O₃ nanoparticles. Three different nonionic surfactants (OP-10, Triton X-100 and Tween-80) have been used for the preparation of microemulsions. The microemulsions were characterized by Zeta Potential Analyzer. The results showed that the OP-10 system possesses wide and stable microemulsion phase regions. The synthesized α- Al₂O₃ powders have been comprehensively characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD). The powders calcined at 900–1150 °C showed the presence of alumina phase with crystal structure, The SEM images showed that the powders was an average diameter of 30–100 nm.