although it is previously known that certain lipophilic drugs may benefit from administering the drug in connection with food intake , the strength of the effect of food intake upon the ospemifene bioavailability obtained in the present investigations was very surprising . particularly compared to the behaviour of other serms , the food effect on ospemifene is remarkable . it was found ( anttila m ., 1997 ) that the intake of food did not have any positive effect on the bioavailability of toremifene , which like ospemifene also has a low aqueous solubility . it was observed that food intake in fact retarded the absorption of toremifene . it has also been reported that the administration of raloxifene , another serm , together with a standardized high - fat meal increases the absorption of raloxifene slightly , but that it does not lead to clinically meaningful changes in systemic exposure . while food intake causes only a 20 % increase of raloxifene absorption , the effect on ospemifene absorption is a 2 - 3 fold increase . the term “ food ” shall be understood to cover any edible foodstuff having a nutritional value as an energy supplier . thus the food can be solid , semisolid or liquid substance comprising one or more of the basic ingredients carbohydrates , fats and proteins . surprisingly , a high percentage of fats or a high energy value in the food intake is not crucial for obtaining a high bioavailability for ospemifene . neither is the amount of food intake crucial for the beneficial effect . it is believed that the secretion of bile acids may play an important role in the improved bioavailability , and therefore any foodstuff being capable of causing secretion of bile acids is expected to work . the drug is considered to be administered in connection with the intake of food if the drug is administered at a time point shortly before the start of the food intake , during the food intake or in a relatively short time after the food intake is completed . a preferable time range is defined to begin 1 hour before starting the food intake and to end 2 hours after starting the food intake . more preferably , the drug is administered at a time point which is in the range defined to begin at a time point during the food intake and to end 1 hour after the food intake was started . most preferably , the drug is administered during the food intake or at a time point which is no later than 0 . 5 hour after starting the food intake . the method of enhancing the bioavailability of ospemifene and related compounds according to this invention is particularly useful when treating women during or after the menopause . however , the method according to this invention is not restricted to women in this age group . the term “ metabolite ” shall be understood to cover any ospemifene or ( deaminohydroxy ) toremifene metabolite already discovered or to be discovered . as examples of such metabolites can be mentioned the oxidation metabolites mentioned in kangas ( 1990 ) on page 9 ( tore vi , tore vii , tore xviii , tore viii , tore xiii ), especially tore vi and tore xviii , and other metabolites of the compound . the most important metabolite of ospemifene 4 - hydroxyospemifene , which has the formula the use of mixtures of isomers of compound ( i ) shall also be included in this invention . the method of enhancing bioavailability is useful in any application of ospemifene , especially when the compound is used for treatment or prevention of osteoporosis or for treatment or prevention of symptoms related to skin atrophy , or to epithelial or mucosal atrophy . a particular form of atrophy which can be inhibited by administering of ospemifene is urogenital atrophy . symptoms related to urogenital atrophy can be divided in two subgroups : urinary symptoms and vaginal symptoms . as examples of urinary symptoms can be mentioned micturation disorders , dysuria , hematuria , urinary frequency , sensation of urgency , urinary tract infections , urinary tract inflammation , nocturia , urinary incontinence , urge incontinence and involuntary urinary leakage . as examples of vaginal symptoms can be mentioned irritation , itching , burning , maladorous discharge , infection , leukorrhea , vulvar pruritus , feeling of pressure and postcoital bleeding . according to previous data , the optimal clinical dose of ospemifene is expected to be higher than 25 mg daily and lower than 100 mg daily . a particularly preferable daily dose has been suggested in the range 30 to 90 mg . at the higher doses ( 100 and 200 mg daily ), ospemifene shows properties more similar to those of tamoxifen and toremifene . due to the enhanced bioavailability according to the method of this invention , it can be predicted that the same therapeutical effect can be achieved with doses lower those recommended earlier . the invention will be disclosed more in detail in the following non - restrictive experimental section . two clinical studies were carried out in order to assess the bioavailability of ospemifene in healthy male subjects after intake of high caloric content ( 860 kcal ) and high - fat breakfast compared to bioavailability of ospemifene administered in fasted condition ( study a ). in a separate study ( study b ), the bioavailability of ospemifene after intake of low caloric content ( 300 kcal ), low - fat breakfast was assessed and the results were compared to those obtained in study a ( i . e . ospemifene bioavailability after intake of high caloric , high - fat breakfast or after ospemifene administering in fasted condition ). in study a , 24 healthy male volunteers ( mean age 23 . 8 years , mean bmi 22 . 8 kg / m 2 ) received single oral doses of 60 mg ospemifene , once under fed condition after consuming a standardised high - fat , high caloric breakfast , and once after an overnight fast . blood samples for pharmacokinetic assessments were drawn during 72 hours at each study period . a washout period between the two treatments was at least 2 weeks . the breakfast consisted of the following ingredients : two eggs fried in butter ( 50 g ), two strips of bacon ( 34 g ), two slices of toast with butter ( 50 g ), 60 g hash brown potatoes and 240 ml of whole milk ( pecentage of fat = 3 . 5 %). the meal provided approximately 150 , 170 and 540 kcal from protein , carbohydrate and fat , respectively . following an overnight fast of at least 10 hours at the study site , the subjects were given the test meal described above 30 minutes before ospemifene dosing ( 60 mg tablet ). the meal had to be consumed over the 30 minutes , immediately followed by administration of ospemifene . following an overnight fast of at least 10 hours at the study site , the subjects were given one ospemifene tablet ( 60 mg ) with 240 ml of water . no food was allowed for at least 4 hours after the ospemifene dose . a substantial effect of food intake was observed on the bioavailability of ospemifene and its main metabolite 4 - hydroxy - ospemifene . fig1 shows the mean serum concentration of ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition ( open circles ) and after a high caloric , high - fat meal ( filled circles ). the results of this study showed clearly that the ospemifene bioavailability was enhanced by concomitant ingestion of ospemifene and a meal . due to the surprising and promising results of this study it was decided to carry out a second study ( study b below ) to find out the effect of a low caloric , low - fat meal on the bioavailability of ospemifene . in study b , 12 healthy male volunteers ( mean age 23 . 8 years , mean bmi 22 . 3 kg / m 2 ) of the 24 subjects in study a were subjected to ospemifene administering in combination with the intake of a low caloric , low - fat meal . the results were compared to those obtained in study a for the same individuals . the composition of the light breakfast ( approximately 300 kcal ) was as follows : two slices of toast with margarine ( 5 g , fat content 60 %), 6 slices ( 30 g ) of cucumber , 240 ml skimmed ( non - fat ) milk and 100 ml orange juice . the test meal provided approximately 50 , 180 and 70 kcal from protein , carbohydrate and fat , respectively . following an overnight fast of at least 10 hours at the study site , the subjects were given the test meal described above 30 minutes before ospemifene dosing ( 60 mg tablet ). the meal had to be consumed over the 30 minutes , immediately followed by administration of ospemifene . fig2 shows the mean serum concentration of ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition ( open circles ; data obtained from study a ); after a high caloric , high - fat meal ( filled circles ; data obtained from study a ) and after a low caloric , low - fat meal ( stars ). fig3 shows the mean serum concentration of the ospemifene metabolite 4 - hydroxy - ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition ( open triangles ; data obtained from study a ); after a high caloric , high - fat meal ( filled triangles ; data obtained from study a ) and after a low caloric , low - fat meal ( crosses ). the results of this study showed clearly that the bioavailability of ospemifene was also enhanced by concomitant ingestion of ospemifene and a low caloric , low - fat meal . although the fat content of the low - fat meal was much lower than that of the high - fat meal , the bioavailabity of ospemifene was only slightly lower for the low - fat meal . therefore it can be concluded that the effect of food on the ospemifene bioavailability is not dependent on the fat content of the meal ingested . instead , stimulation of bile flow due to meal ingestion may enhance the solubilisation of ospemifene . it will be appreciated that the methods of the present invention can be incorporated in the form of a variety of embodiments , only a few of which are disclosed herein . it will be apparent for the expert skilled in the field that other embodiments exist and do not depart from the spirit of the invention . thus , the described embodiments are illustrative and should not be construed as restrictive . anttila m . effect of food on the pharmacokinetics of toremifene . eur j cancer , 1997 ; 33 , suppl 8 : 1144 , 1997 . kangas l . biochemical and pharmacological effects of toremifene metabolites . cancer chemother pharmacol 27 : 8 - 12 , 1990 . kauffman r f , bryant h u . selective estrogen receptor modulators . drug news perspect 8 : 531 - 539 , 1995 .
this invention relates to a method for enhancing the bioavailability of a therapeutically active compound of the formula or a geometric isomer , a stereoisomer , a pharmaceutically acceptable salt , an ester thereof or a metabolite thereof , wherein said compound is administered orally to the individual in connection with the intake of food .