6082
The solubility vs . pH profiles of five ionizable drugs of different nature ( a monoprotic acid , a monoprotic base , a diprotic base and two amphoteric compounds showing a zwitterionic species each one ) have been determined through two different methodologies : the classical shake - flask ( S - F ) and the potentiometric Cheqsol methods using in both instances the appropriate Henderson - Hasselbalch ( H - H ) or derived relationships .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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