months furthermore the isomer hc21 b began to make its appearance at the three month interval and was found at the six month endpoint of the study in a concentration of 5 00 weight percent of the hc17 b content furthermore there were various other impurities found at the six month endpoint in a percentage of 0 56 weight percent in contrast the formulation which did not contain the safflower oil r6539 although starting out containing slightly more hc17 b it lost this component more rapidly and wound up with a considerably lower weight percentage of 0 86 at the six month endpoint of the study as would be expected the formulation without the safflower oil and its constituent linoleic acid contained an even larger percentage of the isomer hc21 b namely 6 36 furthermore other impurities were found in this formulation after six months in a much larger percentage as well namely 2 81 weight percent as compared to only 0 56 weight percent as can be seen from this data adding the omega 6 acid component in the form of the linoleic acid containing safflower oil considerably increased the stability of the valuable hydrocortisone 17 butyrate compound in fact the formulation which did not contain the safflower oil lost approximately 18 of its original hc17 b whereas the formulation containing the safflower oil lost only approximately 6 in other words the improvement in stability was practically threefold furthermore the level of the hc21 b isomer and the other impurities was about 60 less in the formulation containing the safflower oil than in the formulation where the safflower oil was absent thus adding an omega 6 acid component in the form of safflower oil has been shown to be an.