Enhanced SPF UV-sunscreen/tricontanyl PVP photoprotecting...

Drug – bio-affecting and body treating compositions – Topical sun or radiation screening – or tanning preparations

Reexamination Certificate

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C424S060000, C424S078020, C424S078080, C424S400000, C424S401000

Reexamination Certificate

active

06436376

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to novel cosmetic/dermatological compositions for topical application, most notably sprayable formulations, for the ultraviolet (UV)-photoprotection of the skin and/or the hair against the damaging effects of UV radiation, in particular solar radiation, and to the use of same for the cosmetic/dermatological applications indicated above.
This invention more especially relates to topically applicable, enhanced SPF UV-A and/or UV-B sunscreen/tricontanyl PVP photoprotecting compositions, particularly sprayable formulations, advantageously comprising the sunscreen avobenzone and also comprising a sunless or artificial tanning agent such as dihydroxyacetone (“DHA”).
2. Description of the Prior Art
It is well known to this art that light radiation of wavelengths of from 280 nm to 400 nm promotes tanning of the human epidermis, and that irradiation of wavelengths of from 280 to 320 nm, i.e., UV-B irradiation, causes erythema and burning of the skin which can impair the development of a natural tan; hence, such UV-B radiation must thus be screened from the skin.
It is also known to this art that UV-A radiation, of wavelengths from 320 to 400 nm, which tans the skin, also adversely affects it, in particular in the case of sensitive skin or a skin which is continually exposed to solar radiation.
UV-A rays cause, in particular, a loss in the elasticity of the skin and the appearance of wrinkles, promoting a premature aging thereof. Such irradiation promotes triggering of the erythematous reaction or enhances this reaction in certain individuals, and may even be the source of phototoxic or photoallergic reactions. Thus, it is desirable to also screen out UV-A radiation.
A wide variety of cosmetic compositions intended for the photoprotection (UV-A and/or UV-B) of human skin is known to this art.
These photoprotective/sunscreen compositions are quite often oil-in-water emulsions (namely, a cosmetically acceptable vehicle, carrier or diluent comprising an aqueous continuous dispersing phase and an oily discontinuous dispersed phase) which contains, in various concentrations, one or more standard lipophilic and/or hydrophilic organic sunscreen compounds capable of selectively absorbing harmful or deleterious UV radiation. These sunscreen compounds (and the amounts thereof) are selected as a function of the desired sun protection factor (the sun protection factor (SPF) being expressed mathematically by the ratio of the irradiation time required to attain the erythema-forming threshold with the UV screening agent to the time required to attain the erythema-forming threshold in the absence of UV screening agent).
Too, there exists an increasing demand for higher SPF suncare products, particularly high SPF sunscreen sprays. High SPFs can be attained by incorporating more sunscreens at elevated levels; however, this is not always feasible, as sunscreens add considerable cost to the formulation and high sunscreen levels can promote increased irritancy.
Corollary thereto, the dibenzoylmethane sunscreen avobenzone, for example, is a particularly attractive chemical UV-absorber/filter. But it is even more difficult to formulate high SPF sunscreen products when the formulation contains avobenzone, as it is incompatible with many other sunscreen filters (for example, formulations with octyl methoxy cinnamate are generally not photostable).
Much more difficult is the formulation of high SPF avobenzone sprayable compositions. Indeed, high SPF sunscreen sprays are commercially available, but these do not contain avobenzone. Typically, high SPF values are obtained by formulating high levels of UV-B absorbing sunscreens, such as octylmethoxy cinnamate. Nonetheless, these formulations provide no protection against longer wavelength UV-A irradiation.
Also representative of the state of the prior art are:
U.S. Pat. Nos. 5,518,712 and 5,916,541 to Stewart and his WO 97/42933, describing sunscreen protection and insect repellent combination compositions purportedly providing SPF factors of about 2 to about 50. These include a sunscreen agent, whatever its chemical/physical structure and variously oxybenzone or benzophenone-3, an insect repellent, an emulsifing agent and a film former, all in an aqueous solvent. These compositions are said to form a thin film on the skin, but are non-greasy to the touch and are easily removed by scrubbing with soap and water. The film former is also said to add waterproofing properties to be subject compositions and one, of many, examples of which is poly(vinyl pyrrolidone/1-triacontene (tricontanyl PVP)).
U.S. Pat. No. 6,074,630 to Devillez et al., relating to delivery systems for sunscreen products that apply a dry, waterproof sunscreen composition to the skin. The sunscreen composition is applied to an article such as paper, nonwoven cloth or porous plastic which is subsequently rubbed onto the skin. Or, the sunscreen may take the form of a wafer or a bar with or without a support article. Among the list of FDA-approved sunscreen agents suitable according to this particular invention is oxybenzone, and, in general, the patented sunscreen products may contain PVP/hexadecene copolymer or other waterproofing agent, e.g., tricontanyl PVP.
Tricontanyl PVP (Ganex WP-660) also appears in Table 1 of U.S. Pat. No. 5,885,557 to Lentini, relating to compositions useful in the phototherapeutic treatment of psoriasis and other proliferative skin diseases. Such compositions comprise dihydroxyacetone and a penetration attenuator, both in a cosmetically and/or pharmaceutically acceptable carrier. The subject compositions are said to be useful in the exploitation during phototherapeutic treatment of the hyper-desquamation characteristics of the psoriatic or otherwise affected skin.
WO 00/41672 also features a combined insect repellent and sunscreen composition, including one or more inorganic sunscreening agents, but which may also include one or more other UV sunscreening agents, generally organic compounds such as oxybenzone or Parsol MCX and, optionally, a film former, preferably tricontanyl PVP.
Cf. EP 0 819 428 A2, assigned to the assignee hereof, and Gupta and Zatz,
J. Cosmet. Sci.,
50, 79-90 (March/April 1999), “In Vitro Method for Modeling Water Resistance of Sunscreen Formulations,” describing formulating two of the most frequently used sunscreens, benzophenone-3 and octyl methoxycinnamate (OMC) into hydroalcoholic, diisopropyl adipate oil prototype compositions and o/w and w/o emulsions. An in vitro procedure was thus developed for measuring the water resistance of sunscreens and assessing their ability to resist washoff.
SUMMARY OF THE INVENTION
It has now unexpectedly and surprisingly been determined that statistically significant, markedly enhanced SPF values can be attained by formulating an effective UV-photoprotecting amount of at least one UV-A and/or UV-B sunscreen, in particular the sunscreen filter avobenzone, with the particular polymeric film former tricontanyl PVP.
It has even more unexpectedly and surprisingly been determined that high SPF sunscreen sprays are provided by formulating UV-A and/or UV-B sunscreen/tricontanyl PVP sprayable compositions; this because of the art-recognized difficulty of achieving high SPF values in sprayable formulations.
Enhanced SPF values have also now been obtained for artificial tanning, or sunless tanning sprays containing UV-A and/or UV-B sunscreens, for example artificial/sunless tanning sprays also containing the artificial tanning agent, dihydroxyacetone (“DHA”).
DETAILED DESCRIPTION OF BEST MODE AND SPECIFIC/PREFERRED EMBODIMENTS OF THE INVENTION
More particularly according to the present invention, the subject compositions contain (a) an effective UV-photoprotecting amount of at least one UV-A and/or UV-B sunscreen and (b) an amount of the copolymer tricontanyl PVP effective to statistically significantly enhance the SPF value of said at least one UV-A and/or UV-B sunscreen, formulated into (c) a topically applicable, cosmetically/derma

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