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The binding of phenylbutazone (I) and oxyphenbutazone (II) to human serum albumin over pH 6.9-9.3 was studied by difference spectrophotometry and equilibrium dialysis. At each pH tested, there was higher binding affinity of I to human serum albumin than II. Equilibrium dialysis showed that over the pH 7-8.2 range both agents had a single high-affinity site and several sites of lower affinity, with the highest binding constant and number of binding sites at pH 7.4 for both I and II. Both techniques showed that the affinity of both drugs to albumin was higher for the neutral form than for the basic form and this transition occurred in both cases around the neutral region (7-7.4). Both the ionized and unionized forms of I and II participated in the binding. In the neutral region, magnesium ion increased the affinity of both drugs to albumin while chloride ion decreased it slightly.

Anthralin and its decomposition products were separated by both column chromatographic and TLC techniques. Two decomposition products were characterized by TLC, melting-point data, and UV and IR spectroscopy. Pure anthralin and its decomposition products also were determined quantitatively.

The stability of aspirin in decaglycerol tetraoleate, decaglycerol octaoleate, and decaglycerol decaoleate was studied at 4, 26, and 45 degrees. Degradation of aspirin in these polyglycerol esters was temperature dependent. Aspirin demonstrated the greatest stability in decaglycerol octaoleate and the lowest stability in decaglycerol tetraoleate at all temperatures studied. The hydroxyl value and the viscosity of the polyglycerol ester appeared to influence the stability of aspirin.