Drug – bio-affecting and body treating compositions – In vivo diagnosis or in vivo testing – Ultrasound contrast agent
Patent
1993-12-23
1996-09-24
Raymond, Richard L.
Drug, bio-affecting and body treating compositions
In vivo diagnosis or in vivo testing
Ultrasound contrast agent
424 951, 424 95, A61K 4900
Patent
active
055588573
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/EP92/01327 filed Jun. 3, 1992.
This invention relates to novel contrast agents, more particularly to new microparticulate contrast agents of use in diagnostic ultrasonic imaging.
It is well known that ultrasonic imaging comprises a potentially valuable diagnostic tool, for example in studies of the vascular system, particularly in cardiography, and of tissue microvasculature. A variety of contrast agents has been proposed to enhance the acoustic images so obtained, including suspensions of solid particles, emulsified liquid droplets, gas microbubbles and encapsulated gases or liquids. It is generally accepted that low density contrast agents which are easily compressible are particularly efficient in terms of the acoustic backscatter they generate, and considerable interest has therefore been shown in the preparation of gas-containing and gas-generating systems.
Initial studies involving free gas microbubbles generated in vivo by intracardiac injection of physiologically acceptable substances have demonstrated the potential efficiency of such bubbles as contrast agents in echocardiography; such techniques are severely limited in practice, however, by the short lifetime of the free bubbles. Interest has accordingly been shown in methods of generating and/or stabilising gas microbubbles for echocardiography and other ultrasonic studies, for example using emulsifiers, oils, thickeners or sugars.
Techniques involving the use of sugars in ultrasound contrast agents are described in, for example, U.S. Pat. Nos. 4,681,119, 4,442,843 and 4,657,756, which disclose the use of particulate solids having a plurality of gas-filled voids and preferably also a plurality of nuclei for microbubble formation. EP-A-0322350, WO 88/03388, EP-A-0123235, EP-A-0122624 and DE-A-3834705 suggest ultrasound contrast agents consisting of fatty acid-coated, gas-containing microparticles which may include sugars such as cyclodextrins, monosaccharides, disaccharides or trisaccharides. U.S. Pat. No. 4,832,941 claims ultrasound contrast agents consisting of a mixture of three components:--(1) macromolecules such as polysaccharides, (2) vegetable oil and (3) soluble iron (III) salts. EP-A-0077752 suggests ultrasound contrast agents consisting of gas bubbles, surface active compounds (including fatty acid salts and derivatives) and viscosity increasing substances (including mono- or polysaccharides). EP-A-0327490 describes gas-containing amylose particles coated with polymers.
Schlief, R. in International Symposium on Contrast Media,Tokyo (1988), pp. 323-328 gives an overview of ultrasound contrast media with focus on SHU 454 (Echovist.RTM.), which is a saccharide-based product under development by Schering AG. The same author in Contrast Media from past to the Future, Symp. Berlin (1987), pp. 179-187 describes SHU 454 further. Loughery, E. J. et al. in Echocardiography (Elsevier) (1990), pp. 279-292 have published a review on study of circulation by myocardial contrast echocardiography with focus on SHU 454, SHU 508 (Levovist.RTM.) and the protein-based Albunex.RTM..
Schlief, R. in Radiology (1991) 178, pp. 213-215 has described clinical use of SHU 454 in hysterosalpingo-contrast sonography of the uterus and fallopian tubes. SHU 454 has also been described in the following publications: Rovai, D. et al., Circulation Supplement III (1990) 82, p. 26; Barzilai, B. et al., Circulation Supplement III (1990) 82, p. 96; Vorwerk, D. et al., Ultraschall in Med. (1990) 11, pp. 146-149; Von Bibra, H. et al., Eur. Heart J. (1990) 11, p. s 112; Wilkenshoff, U. et al., Eur. Heart J. (1990) 11, p. s 113; El Mouaaouy, A. et al., Surg. Endosc. (1990) 4, pp. 114-117; Smith M. D. et al., JACC (1984) 3, pp. 992-998; Lange, L. et al., Arzneim.-Forsch./Drug Res. (1986) 36(II), pp. 1037-1040; Fritzsch, Th. et al., Invest. Radiol. (1988) 23 (Suppl 1), pp. 302-305; Arisawa, J. et al., International Symposium on Contrast Media., Tokyo (1988), pp. 331-332; Rovai, D. et al., JACC (1987) 10, pp. 125-134; Heidelmeyer, C. F. et al., J. Car
REFERENCES:
patent: 4985233 (1991-01-01), Klaveness et al.
Wheatley et al.; "Contrast Agents For Diagnostic Ultrasound: Development And Evaluation Of Polymer-Coated Microbubbles"; Biomaterials, vol. 11, No. 9, Nov. 1990, pp. 713-717.
Klaveness Jo
Rongved P.ang.l
Strande Per
Cebulak Mary C.
Nycomed Imaging AS
Raymond Richard L.
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