Stabilization and Release Behavior of W1/O/W2-Type Multiple Emulsions Using Various Block Copolymer Emulsifier and Stabilizer

다양한 Block Copolymer를 유화제 및 안정화제로 사용한 W1/O/W2-Type 다중에멀젼의 방출거동 및 안정성

  • Haw, Jung-Rim (Dept. of Ind. Chemistry, College of Engineering, Kon Kuk Univ.) ;
  • Kim, Cheol-Hun (Research and Development Center, Evas Cosmetics Co., Ltd.)
  • 허정림 (건국대학교 공과대학 공업화학과) ;
  • 김철훈 (에바스화장품 기술연구소)
  • Received : 1996.06.28
  • Accepted : 1997.07.26
  • Published : 1997.08.10

Abstract

A new approach to obtain stable $W_1/O/W_2$ multiple emulsions has been studied ; The basis of the interfacial interaction between a PCL-PEO-PCL triblock copolymer and a lipophilic emulsifier in the dispersed oil phase was examined. $W_1/O/W_2$ multiple emulsions were prepared by the two-step method. Arlacel P-l35 was used as a liphophilic emulsifier and Synperonic PE/F 127 as a hydrophilic one. Eutanol-G was used as an oil phase. NaCl was encapsulated within the multiple emulsion droplets as the internal marker and its release rate studies were carried out. The suability of the multiple emulsions have been assessed by measuring Separation Ratios(%) and microscopic observations. The release of NaCl was significantly reduced in $W_1/O/W_2$ multiple emulsions containing PCL-PEO-PCL triblock copolymer(2k-4k-2k or 6k-4k-6k) in the oil phase. It may be concluded that the copolymer and the emulsifier form effective interfacial complex to enhance stability and to control the release rate. The effective diffusion coefficients of the NaCl were estimated as $2.64{\times}10^{-15}s$and $3.23{\times}10^{-16}gcm^2/s$ for the $W_1/O/W_2$ multiple emulsion containing 1.2 wt % of PCL-PEO-PCL triblock copolymers with compositions of 2k-4k-2k and 6k-4k-2k, respectively. The rate of release decreased with the increase of the initial concentration of NaCl. The results were examined in view of Higuchi mechanism. A kinetic model which is similar to the model for release of dispersed drugs from a polymeric matrix was found to be suitable for the release of NaCl from $W_1/O/W_2$ multiple emulsions.

안정한 $W_1/O/W_2$ 다중에멀젼을 얻기 위한 새로운 시도가 연구 되었다; 오일상에 분산된 친유성 유화제와 PCL-PEO-PCL triblock copolymer 사이의 계면상호 작용이 연구되었다. $W_1/O/W_2$ 다중에멀젼은 2단계 방법으로 제조하였다. 친유성 유화제로서 Arlacel P-135와 친수성 유화제로서 Synperonic PE/F 127을 사용하였으며, Eutanol-G를 오일상으로 사용하였다. 다중에멀젼의 내부수상에 시약 방출물질로서 NaCl을 첨가하였으며, 이의 방출속도가 연구되었다. 다중에멀젼의 안정성은 분리도 측정과 광학현미경을 이용하여 평가하였다. 오일상에 PCL-PEO-PCL triblock copolymer를 용해하여 실험한 결과 2k-4k-2k와 6k-4k-6k의 조성 갖는 copolymer로 제조한 다중에멀젼에서 NaCl의 방출이 크게 감소하였다. 이것은 copolymer와 유화제가 안정성 증대와 방출 속도를 조절하는 효과적인 계면 복합체를 형성하기 때문이라고 사료된다. 2k-4k-2k의 조성 갖는 PCL-PEO-PCL triblock copolymer 1.2wt%의 함량으로 제조한 다중에멀젼에서 NaCl의 확산계수는 $2.64{\times}10^{-15}gcm^2/s$이고, 6k-4k-6k에서는 $3.23{\times}10^{-16}gcm^2/s$값을 얻었다. NaCl의 초기 농도의 증가에 따라 NaCl 방출이 감소하였고, Higuchi의 방출 모델식을 개정하여 적용한 결과, 고분자 matrix에 분산된 시약의 방출모델과 유사한 kinetic모델이 다중에멀젼에서 NaCl의 방출에 적당함이 발견되었다.

Keywords

Acknowledgement

Supported by : 건국대학교

References

  1. J. Colloid Interface sci. v.57 no.2 Sachio Matsumoto;Yoshiko Kita;Daizo Yonezawa
  2. J. Colloid Interface sci. v.62 no.1 Yoshiko Kita;Sachio Matsumoto;Daizo Yonezaya
  3. Acta Pharmaceutica Succia v.15 no.1 Arne F. Brodin;Dalia R. Kavaliunas;Sylvan G. Frank
  4. Chemistry and Industry v.3 Satnley S. Davis
  5. J. Pharm. Pharmacol. v.34 Natalie J. Morris;B. Warburton
  6. J. of Controlled Release v.3 T. K. Law;T. L. Whateley;A. F. Florence
  7. J. of Controlled Release v.33 Y. Sela;S. Magadassi;N. Garti
  8. Pharm. Aceta Helv. v.66 no.12 Shan Yang Lin;Wen Hsiuwu
  9. Polymeric Surfactants Irja Piirma
  10. Emulsions and Emulsion Technology Kenneth J. Lissant
  11. The Lancet v.771 Multiple Emulsions W. J. Herbert
  12. J. Microencaps ulation v.6 J. A. Omotosho;T. L. Whateley;A. T. Florence
  13. J. Pharm. Sci. v.52 T. Higuchi
  14. Encyclopedia of Emulsion Technology P. Becher