Process for making capsules

• US 3,341,466 A
• Filed: 10/31/1966
• Issued: 09/12/1967
• Est. Priority Date: 10/31/1966
• Status: Expired due to Term

• Current Assignee: Eurand America Incorporated
• Original Assignee: Carl Brynko, Joseph A. Bakan, Joseph A. Scarpelli, Robert E. Miller
• Inventors: CARL BRYNKO, Bakan, Joseph A., Miller, Robert E., Scarpelli, Joseph A.
• Application Number:
  US04/591,023
• Time in Patent Office: 316 Days
• US Class Current: 427/213.35
• CPC Class Codes: B01J 13/10 Complex coacervation, i.e. interaction of oppositely charged particles
• CPC Class Codes: Y10T 428/2984 Microcapsule with fluid core [includes liposome]
• CPC Class Codes: Y10T 428/2987 Addition polymer from unsaturated monomers only
• CPC Class Codes: Y10T 428/2989 Microcapsule with solid core [includes liposome]

Claims

1. A PROCESS FOR MAKING CAPSULES HAVING WALLS OF GELLED COMPLEX HYDROPHILIC FILM-FORMING POLYMERIC MATERIAL AND NUCLEI OF SUBSTANTIALLY WATER-IMMISCIBLE MATERIAL, INCLUDING THE STEPS OF PROVIDING AN AQUEOUS SOLUTION CONTAINING INTENDED NUCLEUS MATERIAL PARTICLES AND AT LEAST TWO KINDS OF HYDROPHILIC POLYMERIC FILM-FORMING MATERIAL HAVING MOLECULES OF OPPOSITE ELECTRIC CHARGE IN THE SOLUTION, AT LEAST ONE OF THE POLYMERIC MATERIALS BEING TEMPERATUREGELABLE AND THE SOLUTION BEING KEPT AT A TEMPERATURE ABOVE THE GELATION POINT OF THE GELABLE COMPONENT AT THE COMMENCEMENT OF THE PROCESS;

LOWERING THE PH OF THE SOLUTION TO A POINT WHERE COACERVATION COMMENCES AND THE HIGHER WEIGHT FRACTIONS OF COACERVATE DEPOSIT ON THE NUCLEUS PARTICLES;

WITH AGITATION LOWERING THE TEMPERATURE JUST INTO THE GELATION RANGE TO COMPLETE COACERVATION AND THE FORMATIO OF SMALL, MORE VISCOUS COARCERVATE ENTITIES WHICH, BECAUSE OF SUCH VISCOUS CONDITION, FORM THICK WALLS AROUND EACH NUCLEUS ENTITY WITHOUT FURTHER PH ADJUSTMENT;

AND THEN DROPPING THE TEMPERATURE, STILL WITH AGITATION, TO A POINT WHERE THE CDEPOSITED WALLS GEL REGARDLESS OF THE AGITATION.