Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
  • B01J13/0052—Preparation of gels
  • B01J13/0065—Preparation of gels containing an organic phase

Definitions

• the present invention relates to novel large hydrogel particles suspended in an aqueous medium and to a continuous extrusion/mixing process for making these kind of hydrogel particles.
• the hydrogel particles comprise two different high molecular weight polymers. One is insoluble in the aqueous medium and is used for network formation and gel integrity. The other is soluble in the aqueous medium and helps control gel swelling and gel strength. Water insoluble materials are entrapped or encapsulated inside the network formed by these two polymers and are thus more efficiently delivered from the aqueous composition ⁇ e.g., liquid cleanser containing the hydrogel particles).
• Gel particles with controllable size and controllable gel strength are prepared simply by first adding (e.g.
• these domains are capable of trapping water insoluble agents, hereafter designated the "benefit agent", within the gel structure, i.e., inside a web or network formed by the network forming polymer (s) and the property modifying polymer(s).
• the hydrogel composition must have sufficient gel strength (generally provided by the first network forming polymer(s)) to retain the integrity of the discrete domains, and to trap and hold the insoluble benefit agent (s) during processing and storage of the aqueous composition.
• the hydrogel must also be soft enough and capable of disintegrating smoothly when the composition is applied to and rubbed onto the intended substrate, such as skin, without causing any undesirable feeling of foreign matter or grittiness, due to the breaking or due to the components of the hydrogel particles.
• the softness of the gel particles can be manipulated by the amount of property modifying polymer (s) and network forming polymer (s) incorporated into the gel composition.
• Polymer systems useful for forming hydrogels (component d) above) with desirable properties comprise in turn (a) a first polymer which is soluble in water but msolubilizes when placed in an aqueous solution composition (component (ui) above); and (b) a second property modifying polymer which ensures the final hydrogel composition is not so strong that it will not disintegrate smoothly when the hydrogel s applied to a substrate, e.g., skin, and but still has sufficient gel strength to retain the benefit agent during processing and storage.
• a substrate e.g., skin
• Thermal gel a tion Suitable polymers that exhibit this type of gelling behavior are those that are soluble in water at a temperature higher than about 40-50°C and which form a gel after the polymer solution is cooled to room temperature.
• examples of such polymers include: l) gel forming polysaccharides such as carrageenans or agars.
• Particularly preferred polymers of this type are the carrageenan polymers.
• Particularly suitable carrageenans are those manufactured by the FMC corporation and sold under the trade name Gelcar GP911, and Gelcarin 379; n) gel forming proteins.
• a second function of the property modifying polymer concerns its effect on gel strength.
• the hydrogel composition is sufficiently strong such that the dispersed hydrogel domains/particles remain discrete in order to effectively trap the benefit agent within their structure, yet that they be sufficiently soft (non-rigid) that the hydrogel domains/particles rub smoothly into the skin during product use. This balance can be achieved by optimizing the polymer composition of the hydrogel .
• the amounts of silicone and skin adhering to the tape were determined by means of X-ray fluorescence spectroscopy
• the tape strips were placed in an X-ray fluorescence spectrometer with the adhesive side facing the beam ot this machine.
• a mask is applied over the tape to define a standardized area in the middle of the tape which was exposed to the X-ray beam.
• the sample chamber of the machine was placed under vacuum before making measurements and the spectrometer was then used to measure the quantities of silicone and sulphur The sulphur was representative of the amount of skin which had transferred to the tape.
• Example 3 The extrusion process described in Example 3 was used to prepare 17 wt% dispersion (2.55 wt% Cholesterol based on the total composition) of the hydrogel. Same surfactant system as Example 3 (Table 3) was used for the preparation. Deposition of Cholesterol from this cleansing composition was determined in Example 13. A comparative example containing 2.5 wt%
• Control 1 is liquid cleanser contains 2.5 wt . % well dispersed cholesterol.
• the composition and preparation are given in Table 9.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Cosmetics (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Applications Claiming Priority (5)

Publications (1)

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• 1997
  • 1997-08-19 CZ CZ99672A patent/CZ67299A3/cs unknown
  • 1997-08-19 CN CN97199151A patent/CN1234751A/zh active Pending
  • 1997-08-19 BR BR9711968A patent/BR9711968A/pt not_active Application Discontinuation
  • 1997-08-19 CA CA002265465A patent/CA2265465C/en not_active Expired - Fee Related
  • 1997-08-19 AU AU43006/97A patent/AU714022B2/en not_active Ceased
  • 1997-08-19 KR KR1019997001543A patent/KR20000035850A/ko not_active Application Discontinuation
  • 1997-08-19 WO PCT/EP1997/004751 patent/WO1998008601A1/en not_active Application Discontinuation
  • 1997-08-19 EP EP97919017A patent/EP0920353A1/en not_active Ceased
  • 1997-08-19 PL PL97331836A patent/PL331836A1/xx unknown
  • 1997-08-19 JP JP51129998A patent/JP3892048B2/ja not_active Expired - Fee Related
  • 1997-08-26 AR ARP970103863A patent/AR009330A1/es unknown

Non-Patent Citations (1)

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