ABSTRACT
The qualification and quantification of dapsone in suspension were developed and shown to be stability indicating by means of a reverse-phase high-performance liquid chromatographic method. The real solubility of dapsone in water was calculated to be 0.208mg/mL at 25 deg C. The enthalpy of solution and the entropy of solution were calculated to be -175.6 J/g and -43605.7 J/K/M, respectively. An extemporaneous suspension was formulated from commercially available dapsone rablets, and the chemical stability of dapsone in the suspension was determined by means of accelerated stability testing. The 91-day analytical stabilty testing study was conducted at 4, 30, 50, 60, and 70 deg C. The energy of activation for the suspension was determined to be -23288.35 J/K/M. The zero-order rate of degradation for dapsone (k0,25) in suspension at 25 deg C was found to be 0.040845 day -1. The first-order rate of degradation for dapsone in solution was found to be 0.196370 (mg/mL)(day-1). The shelf life for the suspension was calulated to be 31.67 days at 25 deg C and 230.76 days under refrigeration at 4 deg C.
