Patents Assigned to Hans Georg Weder
  • Patent number: 5152923
    Abstract: An aqueous phase, an oil of a triglyceride or fatty acid ester, and, per part by weight of oil 0.05 to 0.4 part by weight of an amphoteric emulsifier are mixed together and processed in a high-pressure homogenizer into a nanoemulsion of less than 200 nm sized oil particles. The emulsifier, exhibiting in the aqueous phase a lamellar liquid-crystalline structure, is preferably a glycerophosphatide of the formula: ##STR1## wherein, R.sub.1 and R.sub.2 mean acyloxy and/or alkyl or alkenyl ether. R.sub.3 is a tri-lower-alkyl ammonio or amino-substituted lower alkyl. The resultant nanoemulsion is stable for a period of several months and does not contain any toxic emulsifier materials. Therefore, it can be advantageously utilized as a vehicle for active agents, for example medicines and/or cosmetic ingredients.
    Type: Grant
    Filed: June 21, 1990
    Date of Patent: October 6, 1992
    Assignee: Hans Georg Weder
    Inventors: Hans G. Weder, Matthias Mutsch
  • Patent number: 4731210
    Abstract: Associates of at least one amphiphilic bilayer-forming substance and a solubilizing agent are formed in an aqueous phase. The bilayer-forming substance itself can be a pharmaceutical substance, or pharmaceutical substances and/or pharmaceutical auxiliaries may be added. The equilibrium conditions for the molar ratio of bilayer-forming substance to solubilizing agent in the associates are then changed in the aqueous phase containing the associates, in order to remove solubilizing agent from the associates, so that the associates combine to form liposomes. In particular, the solubilizing agent concentration in the aqueous phase is reduced, for example by dilution with additional aqueous phase. The change is effected at a rate which is sufficiently high for formation of liposomes having a predefined number of double layers. Furthermore, the rate of change in the aqueous phase is kept virtually constant with respect to location and time. The liposomes thereby achieve a predefined, virtually homogeneous size.
    Type: Grant
    Filed: January 7, 1982
    Date of Patent: March 15, 1988
    Assignee: Hans Georg Weder
    Inventors: Hans G. Weder, Otmar N. Zumbuhl, Reto A. Schwendener, Maximilian Asanger
  • Patent number: 4438052
    Abstract: A process for producing bilayer vesicles from a colloidal solution comprising mixed micelles of a bilayer-forming substance and a detergent, comprises removing the detergent from the micelle-containing colloidal solution by means of flow-through dialysis whereby the colloidal solution is dialyzed against a dialysis liquid in a chamber whose walls are at least partially formed by a semi-permeable membrane, wherein the dialysis liquid is moved along the outer side of the semi-permeable membrane at a velocity such that the detergent concentration in the dialysis liquid, on at least 90% of the active surface of the membrane, is at most 10% of the detergent concentration in the micelle solution in contact with the other side of the membrane, and wherein a homogeneous detergent concentration is maintained in the micelle solution by the movement of the latter.
    Type: Grant
    Filed: January 14, 1981
    Date of Patent: March 20, 1984
    Assignee: Hans Georg Weder
    Inventors: Hans G. Weder, Otmar Zumbuhl, Reto Schwendener, Manfred Milsmann