Effects of Particle Size and Stabilizing Agents upon Dielectric Properties of Water-in-Oil Type Emulsions

スポンサーリンク

概要

• 論文の詳細を見る

• The dielectric relaxation due to the interfacial polarization of water-in-oil type emulsions (W/O emulsions) was investigated at frequencies ranging from 10 kHz to 3 MHz. In preparing W/O emulsions, differences of mixing or micronizing efficiency arise between bench-scale and production-scale apparatus owing to the difference of mixing or shear rate. Therefore, the size of dispersed particles can be regarded as an index of the mechanical effect arising from the mixing apparatus. Firstly, the relationship between the size of dispersed particles and the dielectric properties of W/O emulsions was investigated. It was found that 1 d after preparation, the degree of particle aggregation leveled off and became fairly steady, and the values, for W/O emulsions with coarse particles, of the limiting dielectric constant at low frequency, ε_l, and parameter α, indicating the distribution of relaxation frequencies, determined from complex plane plots, were greater than for those for emulsions with fine particles. The value of ε_l is thought to be related to the thickness of the surfactant layer between aggregated particles rather than to the size of particle clusters, but the relation becomes more ambiguous as the concentration of surfactant becomes higher. Relaxation frequency, f_0,decreases with increasing particle aggregation. Secondly, in order to obtain good emulsification in the W/O emulsion, the stabilizing effects of 23 stabilizing agents upon the state of dispersion of W/O emulsion were evaluated by dielectric measurement. Primary emulsifiers for micronizing dispersed particles, such as polyoxyethylene (POE) (6) sorbitan monooleate, secondary emulsifiers for protecting interface membranes, such as phytosterol, and lipojelling additives, such as aluminum stearate, decreased the value of ε_l of W/O emulsions. From the present study, it was concluded that dielectric evaluation can be applied to examine the mechanical effects on emulsification and to as an aid in the selection of optimum additives and vehicles for a W/O emulsion.

• 公益社団法人日本薬学会の論文
• 1985-12-25

著者

• 広田 貞雄

  Pharmaceutical Formulation Research Center Research Institute Daiichi Pharmaceutical Co. Ltd. :(pres

• 金子 英雄

  Pharmaceutical Formulation Research Center Research Institute Daiichi Seiyaku Co. Ltd.

関連論文

• Effect of Crystallinity on the Percutaneous Absorption of Corticosteroid. II. Chemical Activity and Biological Activity
• Effect of Crystallinity on the Percutaneous Absorption of Corticosteroid. I. Determination of the Degree of Crystallinity of Hydrocortisone Acetate in Ground Mixtures with Crystalline Cellulose
• Estimation of the Degree of Crystallinity and the Disorder Parameter in a Drug by an X-Ray Diffraction Method with a Single Sample
• A Spray-Drying Method for Mass Production of Liposomes
• Possibility of Heat Sterilization of Liposomes
• Texture Study on Optimum Formulation of Molded Poultices
• W/O型抗炎症エマルジョン製剤のコロイド化学的安定性に関する誘電的研究
• Effects of Particle Size and Stabilizing Agents upon Dielectric Properties of Water-in-Oil Type Emulsions
• Dielectric Studies of Emulsions of Polyol in Hydrophobic Colloidal Silica-Oil Gel
• Dielectric Studies on Emulsion of Aqueous Agarose Gel in Hydrophobic Colloidal Silica-Oil Gel
• Fused 1,3-Oxazine Derivatives. Synthesis of 2H-1,3-Oxazino [5,6-b]-quinoxaline-2,4 (3H)-diones (1-Oxaalloxazines), 2H-1,3-Oxazino-[6,5-b] quinoline-2,4 (3H)-diones (5-Deaza-1-oxaalloxazines), and 2H-Pyrido [3,2-e]-1,3-oxazine-2,4 (3H)-diones
• Dielectric Studies on Emulsion of Water in Hydrophobic Colloidal Silica-Oil Gel. II
• Dielectric Studies on Emulsion of Water in Hydrophobic Colloidal Silica-Oil Gel
• Stability of Ascorbic Acid in Fused System Containing Ascorbic Acid and Mannitol
• Estimation of the Shelf Life of a Drug in Its Solid State. II. A Proposition for a New Kinetical Equation of Gas-Solid Reactions for Pharmaceutical Solids
• Estimation of the Shelf Life of a Drug in Its Solid State. I. An Application of Lacey's Theory to a Kinetic Analysis of an Air Oxidation of Ascorbic Acid in Its Solid State

もっと見る 閉じる

スポンサーリンク