SPRAY-CONGEALED FORMULATIONS OF SULFAETHIDOLE (SETD) AND WAXES FOR PROLONGED-RELEASE MEDICATION - EFFECT OF MODIFIERS

An investigation was undertaken to examine the effects of the addition of certain substances—viz., low molecular weight polyethylene, ethylcellulose 20 cps., and glyceryl ester of hydrogenated rosin, to carnauba wax, hydrogenated castor oil, and synthetic wax‐like ester, on the in vitro dissolution patterns of spray‐congealed particles of sulfaethidole (SETD) and wax‐modifier combinations. The pneumatically atomized and congealed particles of the drug‐wax‐modifier suspensions were observed to possess log‐normal particle‐size distributions. These were characteristic for a particular wax. The addition of low molecular weight polyethylene was observed to increase the particle size significantly for all three wax formulations. The in vitro dissolution patterns appear to be second order, being functions of the effective surface area and the weight of drug available for dissolution. The dissolution patterns of SETD from the three wax formulations were observed to be characteristic for each wax and dissolution medium. The addition of low molecular weight polyethylene was observed to retard the dissolution rates of SETD from hydrogenated castor oil and synthetic wax‐like ester formulations. The addition of ethylcellulose tended to increase the dissolution rate from carnauba wax and synthetic wax‐like ester formulations. The addition of glyceryl ester of hydrogenated rosin tended to decrease the dissolution rate of the drug from carnauba wax and hydrogenated castor oil formulations. Copyright © 1968 Wiley‐Liss, Inc., A Wiley Company