Fluorescence Spectroscopy Studies on Micellization of Poloxamer 407 Solution

  • Lee, Ka-Young (College of Pharmacy and Research Institute of Drug Development, Chonnam National University) ;
  • Shin, Sang-Chul (College of Pharmacy and Research Institute of Drug Development, Chonnam National University) ;
  • Oh, In-Joon (College of Pharmacy and Research Institute of Drug Development, Chonnam National University)
  • Published : 2003.08.01

Abstract

It has been reported that at low temperature region, poloxamers existed as a monomer. Upon warming, an equilibrium between unimers and micelles was established, and finally micelle aggregates were formed at higher temperature. In this study, the fluorescence spectroscopy was used to study the micelle formation of the poloxamer 407 in aqueous solution. The excitation and emission spectra of pyrene, a fluorescence probe, were measured as a function of the concentration of poloxamer 407 and temperature. A blue shift in the emission spectrum and a red shift in the excitation spectrum were observed as pyrene transferred from an aqueous to a hydrophobic micellar environment. From the $I_1/I_3 and I_{339}/I_{333}$ results, critical micelle concentration (cmc) and critical micelle temperature (cmt) were determined. Also, from the fluorescence spectra of the probe molecules such as 8-anilino-1-naphthalene sulfonic acid and 1-pyrenecarboxaldehyde, the blue shift of the $\lambda_{max}$ was observed. These results suggest a decrease in the polarity of the microenvironment around probe because of micelle formation. The poloxamer 407 above cmc strongly complexed with hydrophobic fluorescent probes and the binding constant of complex increased with increasing the hydrophobicity of the probe.

Keywords

References

  1. Alexandridis, P. and Hatton, T. A., Poly(ethylene oxide)-poly (propylene oxide)-poly(ethylene oxide) block copolymer surfactants in aqueous solutions and at interfaces. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 96, 1-46 (1995) https://doi.org/10.1016/0927-7757(94)03028-X
  2. Bohorquez, M., Koch, C., Trygstad, T., and Pandit, N., A study of the temperature-dependent micellization of pluronic F127. J. Colloid Interface Sci., 216, 34-40 (1999) https://doi.org/10.1006/jcis.1999.6273
  3. Cho, C. W., Shin, S. C., and Oh, I. J., Thermorheologic properties of aqueous solutions and gels of poloxamer 407. Drug Dev. Ind. Pharmacy, 23, 1227-1232 (1997) https://doi.org/10.3109/03639049709146162
  4. Gaisford, S., Beezer, A., Mitchell, H. C., Bell, P. C., Fakaorede, F., Finnie, J. K., and Williams, S. J., Temperature induced aggregation in aqueous solution of a series of PEO-PPO-PEO copolymers. Int. J. Pharm., 174, 39-46 (1998) https://doi.org/10.1016/S0378-5173(98)00223-3
  5. Kalyanasundaram, K. and Thomas, J. K., Environmental effects on vibronic band intensities in pyrene monomer fluorescence and their application in studies of micellar systems. J. Am. Chem. Soc., 99, 2039-2044 (1977) https://doi.org/10.1021/ja00449a004
  6. Mortensen, K. and Pedersen, J. S., Structural study on the micelle formation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer in aqueous solution. Macromolecules, 26, 805-812 (1993) https://doi.org/10.1021/ma00056a035
  7. Pandit, N., Trygstad, T., Croy, S., Bohorquez, M. and Koch, C., Effect of salts on the micellization, clouding, and solubilization behavior of pluronic F127 solutions, J. Colloid Interface Sci., 222, 213-220 (2000) https://doi.org/10.1006/jcis.1999.6628
  8. Schild, H. G. and Tirell, D. A., Microheterogeneous solutions of amphophilic copolymers of N-isopropylacrylamide. Langmuir, 7, 1319-1324 (1991) https://doi.org/10.1021/la00055a005
  9. Schillen, K., Glatter, O., and Brown, W., Characterization of a PEO-PPO-PEO block copolymer system. Prog. Colloid Polym. Sci., 93, 66-71 (1993) https://doi.org/10.1007/BFb0118476
  10. Shin, S. C., Cho., C. W. and Oh, I. J., Enhanced efficacy by percutaneous absorption of piroxicam from the poloxamer gel in rats. Int. J. Pharm., 193, 213-218 (2000) https://doi.org/10.1016/S0378-5173(99)00339-7
  11. Vasilescu, M., Caragheorgheopol, A. and Caldarar, H., Aggregation numbers and microstructure characterization of selfassembled/ aggregates of poly ethylene oxide surfactants and related block-copolymers, studied by spectroscopic method. Advances in Colloid and Interface Science, 89, 169-194 (2001) https://doi.org/10.1016/S0001-8686(00)00062-2
  12. Wilhelm, M., Zhao, C., Wang, Y., Xu, R., Winnik, M, Mura, J., Riess, G., and Croucher, M., Poly(styrene-ethylene oxide) block copolymer micelle formation in water. Macromolecules, 24, 1033-1040 (1991) https://doi.org/10.1021/ma00005a010
  13. Yong, C. H., Choi, Y. K., Kim, Y. I., Park, B. J., Quan, Q. Z., Rhee, J. D., Kim, C. K., and Choi, H. G., Physicochemical characterization and in vivo evaluation of thermosensitive diclofenac liquid suppository. Arch. Pharm. Res., 26, 162-167 (2003) https://doi.org/10.1007/BF02976664
  14. Yu, G., Deng, Y., Dalton, S., Wang, Q., Attwood, D., Price, C., and Booth, C., Micellization and gelation of triblock copoly (oxyethylene/oxypropylene/oxyethylene), F127. J. Chem. Soc. Faraday Trans., 88, 2537-2544 (1992) https://doi.org/10.1039/ft9928802537
  15. Zana, R. and Lang, J., Recent developments in fluorescence probing of micellar solutions and microemulsions. Colloids Surf., 48, 153-171 (1990) https://doi.org/10.1016/0166-6622(90)80225-S
  16. Zhou, Z. and Chu, B., Light scattering study on the association behavior of triblock polymers of ethylene oxide and propylene oxide in aqueous solution. J. Colloid Interface Sci., 126, 171-180 (1988) https://doi.org/10.1016/0021-9797(88)90111-7