Thermal Studies of Acetaminophen Drug by DSC Cooling and Photovisual

摘要

The acetaminophen is an analgesic derivate of the fenacetine. It is an alternativerneffective like analgesic and antipyretic. An important factor in the formulation is therncrystalline or amorphous form of the drug. The drug substances in general present differentrnphysical-chemistries properties, besides melting point and solubility. According to MERCKrníNDEX, the melting point of the acetaminophen drug, is among 169-170 ℃. According tornUSP 23, among 168-171 ℃. According to BRITISH PHARMACOPOEIA, 168-172 ℃.rnThe melting point of acetaminophen crystalline form was characterized by DSC, DSCrncooling, DSC photovisual and by conventional technique . The DSC curves ofrnacetaminophen drug at a heating rate at 1, 3 and 5 ℃ min~(-1) showed endothermic peaksrncorresponding to melting point at 168,20; 168,90 and 169,68 ℃ respectively. The DSCrncooling data shows the drug submitted a one heating run followed by cooling and heatingrnrun again which showed two endothermic peaks at 170,13 , 170,62 ℃ respectively, and onerncrystallization peak at 154,46 ℃, a case of enantiotropy. Acetaminophen mixture for directrncompression of tablets presented only one endothermic peak at 169.8 ℃. The phaserntransitions corresponding to the crystallization and melting processes did not happened.rnThe enantiotropy form of acetaminophen was confirmed for the pictures obteined by DSCrnphotovisual. DSC Cooling and DSC Photovisual are powerful tool in the characterization ofrnacetaminhphen crystal and amorphous.