Abstract
Films formed from an aqueous dispersion of ethylcellulose mixed with hydroxypropylmethylcellulose were deposited onto sodium bicarbonate, microcrystalline cellulose, and acetylsalicylic acid (ASA) tablets. Upon storage at elevated temperatures and relative humidity, no changes in disintegration times were observed with the sodium bicarbonate tablets or with tablets containing microcrystalline cellulose. Marked increases were observed in disintegration times with the ASA tablets, these increases being dependent on both temperature and relative humidity. Examination of films by scanning electron microscopy indicated that coalescence of particles within the films had occurred in those samples where increases in disintegration times were observed.