sixty female subjects , ages 20 - 80 , who completed an informed consent procedure with ludwig type i - iii female pattern hair loss ( ludwig , et al ., br . j . dermatol ., 97 ( 3 ): 247 - 254 ( 1977 )) were enrolled in a 6 - month pilot study using a double blinded , placebo controlled design . subjects were assigned randomly to the placebo ( 20 , vehicle only ) or active groups ( 40 , vehicle containing 0 . 5 % octyl nicotinate and 5 . 0 % myristryl nicotinate ). dispensed products were packaged in identical containers . trisiloxane and dimethicone were major components of the formulation . since the actives are vitamin - derived substances , both the placebo and the active preparations studied are classified as cosmetics under the current fda guidelines . at baseline , subjects were dispensed a one month supply of assigned study product . the first dose was applied at the research center by a study nurse . subjects were instructed to apply the formula , at night , in 6 metered doses to the scalp in the following manner : one drop each to the right anterior scalp , left anterior scalp , right middle top of the head , left middle top of the head , right posterior scalp , and left posterior scalp . if the hair was washed , the study medication was applied following hair washing . all subjects were supplied with the same shampoo . the frequency of hair washing was self selected . subjects were asked to maintain the entry style , color , and curl of their hair throughout the study . subjects returned at monthly intervals for evaluation of increased hair fullness , scalp irritation , or other adverse events and product dispensing . they were asked to shampoo the morning of study visit and to avoid applying styling products . subjects were also asked to assess the appearance of their hair . standardized photography was used for the assessment of hair fullness since increases in hair fullness over the 6 - month study period are normally not detectable by either the investigator or the subjects . at baseline , month 3 , and month 6 , photos of the scalp vertex , with the hair combed away from the vertex like the spokes of the wheel , and the central partline , with the hair combed smoothly to both sides of the head . these images were taken in duplicate with one set provided to the subjects for personal comparison while the second set remained at the study center . standardized 35 mm photography was conducted at baseline , 2 , 4 , and 6 months as follows : vertex view with hair combed away from the crown , superior view with hair parted in midline , frontal view with headband to reveal the anterior hairline . the images were taken with the subject &# 39 ; s head in a 3 - point mount specially designed for hair loss photography . evaluation was completed on the 6 month photographs as this represents a minimal time to detect changes in hair fullness . of the total subjects enrolled in the study , 32 of 40 active and 12 of 20 placebo subjects completed the study . a relatively high withdrawal rate is typical for hair fullness / growth studies but it is interesting to note that proportionally twice as many subjects in the placebo group withdrew from the study . overall tolerability of the topical formulations was very good . there were no serious adverse events reported and the mild adverse events included 9 reports of scalp stinging , 2 of scalp burning , 12 of scalp itching , 4 reports of scalp redness , and 7 reports of eye irritation . these events occurred in both placebo and active groups indicating that the volatile vehicle and not the active ingredients was the source of the irritation . the study yielded investigator assessments , subject assessments , and photographic assessments . statistical polaroid photos and subject assessments revealed a positive trend , but did not reach significance at a p value of 0 . 05 , which was not unexpected for a 6 - month study . the key assessment was based on the standardized 35 mm photographs that were evaluated by a blinded investigator for assessment of improvement in hair fullness . each set of images was rated on a scale of minus 1 for decreased hair fullness , zero for no change , or plus 1 for increased hair fullness . these data are summarized in table 1 . the data comparing the placebo and active groups demonstrate an increased benefit for the active group with a p value of 0 . 04 as analyzed by the one tailed mann whitney test for nonparametric data . the placebo effect observed in this study is not uncommon for hair fullness studies . an example of the effect of nicotinic acid derivatives on thinning hair as documented by 35 mm photography at baseline and 6 months of application is shown in fig1 . this example describes how application of the nicotinic acid alkyl esters of the invention improved the energy status of hair follicles , by increasing nad content therein . hair samples were taken from subjects treated with the formulation of example 1 , and tested for nad content , as well as dna content , using art recognized methods . the results follow , in table 2 , and fig2 . these results show clearly that the nicotinic acid alkyl esters of the invention increase the amount of nad in hair follicles . expressed another way , the energy content of the follicles increased , and the increases , as can be seen , are quite dramatic . the foregoing disclosure sets forth various features of the invention , which relates to compositions useful in treating hair growth disorders , such as pattern baldness , and the use of these compositions . the compositions comprise a first nicotinic acid alkyl ester , wherein the alkyl chain of the ester , which may be branched or straight chain , contains from 11 to 22 ch 2 groups . especially preferred is the nicotinic acid alkyl ester where the alkyl group contains 14 ch 2 groups , i . e ., myristyl nicotinate . the second nicotinic acid alkyl ester is one where the alkyl group , which may also be branched or straight chained , contains from 1 to 10 ch2 groups , preferably 6 to 10 ch 2 groups . especially preferred is the straight chain nicotinic acid alkyl ester octyl nicotinate . the two nicotinic acid alkyl esters are combined in a formulation , optionally with a carrier , which may be water , a soap , a detergent , or any other standard carrier useful for application to the scalp . the formulations of the invention may be in any form that is suitable for administering materials to the scalp . exemplary , but by no means exclusive examples of such forms are topical solutions shampoos , rinses , aerosols , emulsions , crèmes , sprays , lotions , gels , and so forth . the compositions are used by applying them to the scalp , such as by washing , massaging , and so forth . it is preferred that the formulations be applied at least once a day , preferably at a dose of from about 0 . 01 % to about 10 %, w / v for each of the components , more preferably from about 0 . 1 % to about 5 % w / v for each component per day . different dosing regiments may also be used . a further feature of the invention is a method for treating a hair loss disorder via administering an amount of a nicotinic acid alkyl ester with a straight chain alkyl group consisting of from about 6 to about 22 , and preferably from about 8 to about 16 carbon atoms , in an amount sufficient to alleviate , reduce , or otherwise treat hair loss . as was shown , supra , these nicotinic acid alkyl esters cause an increase in intrafollicular nad + content , as manifested in an increased nad + / dna ratio , in the hair follicles . thus , in turn , results in an increase in intrafollicular energy content , which may be the reason for the alleviation of the hair loss . one or more nicotinic acid alkyl esters may be so used , with the c8 and c14 alkyl chains being especially preferred . also a part of the invention is a method for increasing thickness or fullness of pre - existing hair , via the use of the compositions of the invention . it has been observed , as these data show , that the use of these formulations , in addition to alleviating hair loss , results in an increase in hair fullness and / or thickness . other aspects of the invention will be clear to the skilled artisan , and need not be reiterated here . the terms and expression which have been employed are used as terms of description and not of limitation , and there is no intention in the use of such terms and expression of excluding any equivalents of the features shown and described or portions thereof , it being recognized that various modifications are possible with the scope of the invention .
the invention relates to formulations useful in treating hair disorders , improving the health of hair , increasing hair growth , and in increasing the niacin content of hair follicles . nicotinic acid alkyl esters having a straight chain alkyl group of from 1 to 22 methylene units , preferably from 6 to 16 methylene units , and most preferably from 8 to 14 methyl units , may be used , alone or in combinations for treating these conditions .