AU2010100375A4 - Lanolin product - Google Patents

Description

1 AUSTRALIA I I I~~t FB RICE & CO Patent and Trade Mark Attorneys Patents Act 1990 LANOLIPS PTY LTD COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: Lanolin product The following statement is a full description of this invention including the best method of performing it known to us:- 2 Field of the Invention This invention relates to skin treatment compositions and methods for treating the skin, particularly for use on moist skin areas, such as the lips. 5 Background to the Invention The skin becomes dry due to excessive loss of water from the stratum corneum when it is exposed to low humidity and/or air movement as well as insufficient 10 hydration from the lower epidermal layers. Even under comfortable ambient conditions, there is a continuous loss of water from the skin as the water content and vapour pressure of the epidermis are higher then the surrounding air. The prevalent use of airconditioning is particularly drying as the airconditioning typically functions to lower the humidity. 15 One approach to treating dry skin is through the use of emollients which are hydrophobic in character. An emollient when applied as film to the skin acts as an occlusive material to prevent passage of water into and out of the skin. In this way, the emollient will act to allow the skin to rehydrate. It is generally recognised that one area of the skin that is prone to drying are the 20 lips. Such drying is exacerbated for example when sleeping in an air conditioned environment or at times when the humidity is otherwise low or there is additional air movement created by, for example, a ceiling fan. Another area of the skin that may be subject to excessive drying is the nipples of nursing mothers. Whilst it has been recognised that lanolin is an effective emollient, it is not per 25 se suitable for skin care or treatment products. This arises out of the fact that it has high viscosity, tackiness and is not easily spread on the skin owing to its unctuous nature. In general terms, most consumers would find the material aesthetically unacceptable for regular use. There are a very large number of other emollient materials that may be use. 30 However, as with lanolin, they are invariably formulated with a range of other material as creams, that is as emulsified water based systems. Whilst recognising that there are a variety of products in the market with purported effectiveness the treatment and prevention of dry skin, the present inventor has identified the need for a product that is not only effective in use on the skin but has 35 no or minimal allergic potential, is easy to use and functions to maintain the lips in a suitably moisturised state whilst sleeping overnight. 1006891 3 Summary of the Invention The present invention consists in an anhydrous skin ointment comprising 75 90% w/v of a non-sticky lanolin, 10-25% w/v lanolin oil, and optionally one or more 5 sunscreens, essential oils, dyes and oil soluble vitamins. In a further aspect, the present invention consists in a method of maintaining skin hydration for a period of at least 6 hours comprising applying to an area of skin an anhydrous skin ointment comprising 75-90% w/v a non-sticky lanolin, 10-25% w/v lanolin oil, and optionally one or more sunscreens, essential oils, dyes and oil soluble 10 vitamins, in an amount sufficient to form a film on the skin. In a still further aspect, the present invention consist in an anhydrous skin ointment consisting of 75-90% w/v of a non-sticky lanolin, 10-25% w/v lanolin oil. Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated 15 element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. Any description of prior art documents herein is not an admission that the documents form part of the common general knowledge in Australia. Description of the Invention 20 Lanolin is the unctuous secretion of the sebaceous glands of sheep which is deposited onto the wool fibres. It softens the fleece and serves to protect the fleece against the elements. It is a wax, not a fat. It is a complex mixture of esters, di-esters and hydroxy esters of high molecular weight lanolin alcohols (69 aliphatic alcohols 25 (C 12

-C

36 ) and 6 sterols have been identified in lanolin) and high molecular weight lanolin acids (approximately 138 acids (C 7

-C

4 1 ) have been identified in lanolin). Lanolin is a by-product of the wool-scouring industry. Wool grease constitutes 10-15% of the weight of sheared wool, depending on the breed of sheep, anatomical area sheared, inner and outer fleece, and season. The 30 average composition of Australian fleeces is 11-16% grease, 6-8% suint (potassium salts of various organic and inorganic acids in the sweat), 10-12% water, 8-19% dirt and 49-61% wool fiber. One hundred kilograms of wool yield about 2 to 4 kilograms of lanolin. Lanolin is recovered by wool-scouring, followed by separation and purification which may include acid cracking or centrifugal washing, neutralization, 35 removal of soaps, filtration, bleaching and deodorization. 1006891 4 There are a variety of lanolin derivatives known which fall into two categories, namely physical derivatives and chemical derivatives. The physical derivatives are formed as a result of physical separation processes whilst the chemical derivatives arise out of chemical modifications of lanolin. One of the best known physical derivatives is 5 lanolin oil which is formed by fractional solvent crystallization. Lanolin oil is the liquid esters of lanolin. It should be noted that whilst lanolin oil is itself an emollient and does not suffer from the tackiness or unctuous character of lanolin, it is unsuitable as it is too fluid and is not substantive to the skin. 10 The present invention is predicated on the careful use of a blend of highly purified lanolin and lanolin oil in a specific ratio so as to obtain an emolliency benefit over a prolonged period of time when applied to skin, such as the lips. One of the characteristics of the lanolin is that is should not be "sticky" nor "oily" It is desirable to use lanolin in the anhydrous form in a grade which is generally 15 regarded as "ultrapure". That is, the material should comply with pharmacopeial standards, for example as set out in the British Pharmacopeia and the US Pharmacopeia (USP). In addition, the material should preferably be free of allergens, be colourless and odourless. A supplier of a suitable material is Croda. This company supplies anhydrous lanolin of a suitable grade under the trade name of Medilan Ultra. 20 Similarly in relation to lanolin oil, hypoallergenic, oil-soluble liquid fractions of anhydrous lanolin USP are suitable for use in the present invention. In addition, the material should preferably be free of allergens, be colourless and odourless. A supplier of a suitable material is Croda. This company supplies lanolin oil of a suitable grade under the trade name of Liquid Medilan Ultra. 25 The concentration of lanolin used in the compositions of the present invention will be in the range of 75-90% w/v, preferably 82-87% w/v, most preferably 83.25% w/v. The concentration of lanolin oil used in the compositions of the present invention will be in the range of 10-25% w/v, preferably 13-18% w/v, most preferably 16.75% w/v. 30 Although it is preferable that the compositions of the present invention consist of lanolin and lanolin oil only, it is possible in some circumstances to include ingredients to improve the organoleptic suitability of the compositions. Examples of such ingredients are dye stuffs, preferably pigment and essential oils such as sweet almond oil and coconut oil. 35 Other functional materials such as oil-soluble vitamins, an example being vitamin E may be included as appropriate. A composition of the present invention 1006891 5 formulated for use in wound healing would desirably include vitamin E. Another functional material is a sunscreen, which is particularly appropriate in a formulation for use on the lips when an individual is exposed to the sun. Examples of sunscreens include octyl methoxycinnimate and benzophenone-3. 5 The compositions of the invention are particularly suitable as lip balms. Typically when applied to the lips before going to bed, a lip balm will continue to provide a moisturising benefit for at least 6 hours, preferably 8 hours. On waking, it will be found that there is a film of the lip balm remaining on the skin. For guidance, about 40 mg is sufficient to apply to the lips. 10 However, it will be appreciated that the compositions may be used on a variety of skin surfaces which may or may not be affected by moisture. Some particular areas are the nipples of nursing mothers, wound areas and the cuticle of the nails. In all cases sufficient of the composition should be applied to create a film on the relevant area of the skin. For example, on the lips about 40 mg may be used. 15 In a preferred embodiment, the compositions of the invention should have the following characteristics when evaluated at a temperature of 20-22*C: soft enough to squeeze out of a plastic tube having a 4mm opening; soft enough to be spread on the skin without lumping so as to form a layer; and hard enough to create a good emulsion layer on the lips or other skin areas. 20 In general terms, the compositions of the invention may be prepared using the following procedure: Weigh a suitable amount of lanolin and lanolin oil and place in a vessel that is capable of being heated. Heat to about 70*C until melted. Allow to cool and whilst about 45*C, fill into heat-sealable plastic ointment tubes. 25 Example So as to better understand the nature of the invention, an example will now be described. 30 Example 1 An ointment was prepared by placing 83.25% w/v of Medilan Ultra lanolin and 16.75% w/v of Liquid Medilan Ultra into a vessel. The vessel was heated to 70*C until melted. After which, it was allowed to cool to 45*C and filled into heat-sealable plastic ointment tubes. 35 Samples of the ointment were subjected to two separate tests. In the first test (The Overnight Lip Test), a 3mm length of ointment was squeezed out of a 4mm 1006891 6 opening in the place ointment tube into which it had been filled. The ointment was applied to the lips, both top and bottom, of an individual so as to form a film without any attempt being made to rub the ointment into the lips. After 8 hours of sleep, the ointment was found to be intact and the lips were properly hydrated. 5 In the second test (The Cuticle Test), a 0.75 mm length of ointment was squeezed out of a 4mm opening in the place ointment tube into which it had been filled. This was applied to the cuticle of a fingernail by using a finger to spread the ointment around the cuticle skin and the nail plate. Sufficient is applied so that the ridge between the cuticle and nail plate is filled with a layer of ointment. It was found that 10 the amount continued to exhibit a moisturising affect on the cuticle until in general use, the ointment was rubbed away. It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the scope of the invention as broadly described. 15 The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 1006891

Claims (2)

1. An anhydrous skin ointment comprising 75-90% w/v of a non-sticky lanolin,

10-25% w/v lanolin oil, and optionally one or more sunscreens, essential oils, dyes and oil soluble vitamins. 5 2. The anhydrous skin ointment of claim 1 comprising 82-87 w/v of non-sticky lanolin and 13-18% w/v lanolin oil. 3. The anhydrous skin ointment of claim 2 comprising 83.25 w/v of non-sticky lanolin and 16.75 % w/v lanolin oil. 4. The anhydrous skin ointment of any one of claim I to 3 wherein the ointment 10 complies with the overnight lip test as hereinbefore described. 5. A method of maintaining skin hydration for a period of at least 6 hours comprising applying to an area of skin an anhydrous skin ointment comprising 75-90% w/v a non-sticky lanolin, 10-25% w/v lanolin oil, and optionally one or more sunscreens, essential oils, dyes and oil soluble vitamins, in an amount sufficient to form 15 a film on the skin. 1006891