Drug – bio-affecting and body treating compositions – Powders – granules or particles of specified mesh or particle...
Reexamination Certificate
1999-03-19
2001-05-08
Nutter, Nathan M. (Department: 1711)
Drug, bio-affecting and body treating compositions
Powders, granules or particles of specified mesh or particle...
C514S962000, C514S963000, C514S964000, C514S965000, C424S451000
Reexamination Certificate
active
06228894
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a softgel-compatible composition containing retinol, and to a softgel-compatible composition containing both retinol and ascorbic acid; and to dispensing containers containing such compositions.
Retinol, along with other retinoids, has enjoyed increasing popularity as an active ingredient in skin care compositions, especially for acne, photoaging, and sun damage. However, more so than other retinoids, retinol tends to decompose on exposure to light, heat, and oxygen. The problem of decomposition has been addressed to some extent by formulating retinol with antioxidants and chelating agents, and storing it in opaque or colored containers, and several patents and published applications, for example, PCT International Application Publication No. WO 93/00085 and European Patent Application Publication Nos. 0 440 398 and 0 586 106, all to Johnson & Johnson, describe water-in-oil emulsions containing retinol, which are asserted to be stable. European Patent Application Publication No. 0 781 551, to Advanced Polymer Systems, discloses an oil-in-water emulsion containing retinol, in which the retinol is entrapped within the pores of solid porous polymeric microparticles. The disclosures of these and other documents referred to in this application are incorporated herein by reference.
Softgel (soft gelatin capsule) formulations have recently become of greater interest in the formulation of products for topical application to the skin, because the softgels provide an attractive single use method for dispensing the product. Typically, these softgels contain 0.1 mL to 2 mL of a fill material, and have a “twist-off” or other removable feature at one end for dispensing the fill material. Such softgels can be prepared by methods well known for the preparation of softgels for oral dosage formulations, i.e. by encapsulating the fill material between two sheets of gelatin as it passes between a pair of die rolls having surface cavities shaped to form the desired shape of the resulting softgel.
However, it is well known in the art that unmodified softgels are incompatible with water, and that typical emulsions, whether water-in-oil or oil-in-water, will degrade the gelatin shell of a softgel.
U.S. Pat. No. 5,587,149 (Punto et al.) discloses a softgel formulation for water-soluble active ingredients, such as ascorbic acid (vitamin C), where the fill material comprises an emulsion of which a first phase includes polyethylene glycol (into which the water-soluble active ingredient is dissolved) and the second phase includes a silicone fluid.
It would be of value to have a softgel-compatible composition containing retinol, and a composition containing retinol and ascorbic acid, and dispensing containers containing such formulations.
BRIEF SUMMARY OF THE INVENTION
In a first aspect, this invention includes a softgel-compatible composition containing retinol and optionally containing ascorbic acid, comprising:
(a) an optionally thickened silicone oil,
(b) retinol-impregnated microparticles, and optionally
(c) ascorbic acid-impregnated microparticles.
In a second aspect, this invention includes a softgel-compatible composition containing retinol and optionally containing ascorbic acid, comprising:
(a) an emulsion comprising a polyethylene glycol and a silicone oil and optionally from
0.01% to 10% by weight of the emulsion of ascorbic acid, and
(b) retinol-impregnated microparticles, and optionally
(c) ascorbic acid-impregnated microparticles.
In a third aspect, this invention includes a dispensing container containing the softgel-compatible composition of the first aspect of this invention.
In a fourth aspect, this invention includes a dispensing container containing the softgel-compatible composition of the second aspect of this invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of this invention, there are obtained softgel-compatible compositions for retinol and for retinol and ascorbic acid, in which the retinol and the ascorbic acid, if present, are present in the composition impregnated into porous microparticles. According to the second aspect of this invention, there are obtained softgel-compatible compositions for retinol and for retinol and ascorbic acid, in which the retinol is present in the composition impregnated into porous microparticles and the ascorbic acid, if present, is present in the composition either in free form and/or impregnated into porous microparticles. Compositions according to this invention are stable and topically cosmetically acceptable, and are also stable in softgels, thereby providing attractive topical forms for retinol, and for retinol and ascorbic acid, in convenient single-use containers. According to the third and fourth aspects of this invention, there are obtained dispensing containers containing the compositions of the first and second aspects of the invention.
Number ranges given in the specification, such as size ranges and the like, should be considered approximate, unless specifically stated.
Ingredient names are taken from the
International Cosmetic Ingredient Handbook,
3rd edition, 1995.
The transitional term “comprising” is an open-ended term synonymous with “including”, and does not exclude additional unrecited elements.
Dispensing Containers
The term “dispensing container” refers to a container suitable for containing the compositions of the first and second aspects of this invention. Dispensing containers are well known in the packaging art; and suitable containers include tubes (of the kind widely used to hold topical formulations, cosmetics, and the like), airless pumps, sachets or pouches, and the like. Such containers are desirably “barrier containers”, which are dispensing containers constructed of materials such that, when filled with the composition and sealed, they effectively prevent contact of the composition with atmospheric oxygen and light, and thereby prevent or minimize oxidative or photocatalyzed degradation of the formulation. Desirably, any free space within the dispensing container after it is filled with the desired content of the composition is filled with an inert gas, such as nitrogen or the rare gases, e.g. argon. A preferred inert gas is nitrogen. Filling a dispensing container with inert gas and sealing it implies that the oxygen be so sufficiently removed and excluded from the container that oxidative degradation of the composition be minimized.
Barrier containers are well known in the packaging art; and are widely used for the storage of prepackaged materials subject to oxidative or photocatalyzed degradation. Such containers are typically prepared from polymeric co-extrusions in which one or more of the polymer layers is a “barrier polymer”, customarily defined as a polymer having an oxygen permeability of less than about 40 cm
3
·&mgr;m/(m
2
·d·kPa) at 23° C. Barrier polymers and their uses are described, for example, in the article entitled “Barrier Polymers” in
The Wiley Encyclopedia of Packaging Technology,
M. Baker, Ed., John Wiley and Sons, New York, 1986. Such containers are also typically prepared from foil laminates (polymeric laminates in which one or more of the layers is a metal foil, especially an aluminum foil, or a metallized polymeric layer); and may also contain other non-polymeric layers. Barrier containers may be made in many forms, but those forms particularly applicable to this invention are preformed or form-fill-and-seal sachets or pouches, tubes, airless pumps, and the like. They are fillable and sealable by methods well known to the packaging art; for example, already capped or sealed and capped tubes open at the bottom end are filled from the open end and sealed by any suitable means, typically by heat sealing (heating either by direct conduction, applicable to all materials, or by inductive heating, applicable if a metal foil or foil laminate is present in the area of the container to be sealed).
A particularly convenient dispensing container is a sachet or pouch formed from a foil laminate, as these containe
Rinaldi Marie A.
Saxena Subhash J.
Tutschek Paul C.
Enhanced Derm Technologies, Inc.
Heller Ehrman White & McAuliffe LLP
Nutter Nathan M.
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