and the top coating membrane the tablets were cured at 60 u00b0 c for 1 hour and then allowed to cool the weight gains obtained for the seal coating membrane the functional coating membrane and the top coating membrane were 1 66 4 5 and 1 66 w w of the weight of the core respectively all of the weight gains were calculated based on the weight of the uncoated tablets the weight gain of the functional coating membrane was varied from 3 to 4 5 w w of the weight of the core the effect of varying the weight gain of the functional coating membrane on the release of the active ingredient from the pharmaceutical composition is shown in fig6 in this example a two hour controlled onset time delay and a sustained release of the active ingredient for about 10 to 22 hours post time delay was achieved the effect of varying the weight gain of the functional coating membrane on the release of glipizide from the pharmaceutical composition was determined using the sequentially ph change method in this method each tablet was exposed to 4 different phs beginning with ph 1 2 from 0 1 hr ph 4 0 from 1 2 hr ph 6 0 from 2 6 hr and ph 7 5 from 6 18 hr the tablets were characterized by usp dissolution apparatus 2 the vessels were filled with 900 ml of dissolution medium at a paddle speed of 100 rpm at 37 u00b0 c a non reactive wire was loosely coiled around each tablet to prevent from sticking to the glass and help it stay at the bottom of the vessel as can be concluded from fig6 in this example the greater the percentage weight.