Stability in solid dosage forms

Because of the good stability of povidone on its own, its stability in solid dosage forms is usually also good. 

As a general rule, anhydrous forms that do not convert to the hydrate below 75% RH (at equilibrium) are likely to exhibit adequate physical and chemical stability in oral solid dosage forms. Adequate manufacturing and packaging can be designed to protect most oral solid dosage forms from exposure to >75% RH. Conversely, hydrates that do not convert to the anhydrous form until the relative humidity drops below about 20% (at equilibrium) are also likely to exhibit adequate physical stability in solid dosage forms. 

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