Why is CU preferred over WV uniformity in solid dosage forms?

The preference for CU over WV uniformity in solid dosage forms is due to CU's ability to provide actual measures of drug content per dosage unit. This approach is crucial for ensuring that each individual dosage unit contains the specified amount of the active pharmaceutical ingredient, allowing for a more accurate assessment of the drug's consistency and effectiveness across different dosages.

When solid dosage forms are evaluated using content uniformity (CU), the actual concentration of the drug in each unit is measured, which helps to affirm that the formulation is within specified limits for active ingredient content. This is especially important in maintaining the safety and efficacy of medications, as variances in drug content can lead to significant therapeutic failures or adverse effects.

In contrast, weight variation (WV) only assesses the weight of dosage forms without providing insights into the actual drug content. While WV can indicate uniformity, it does not ensure that the active ingredient is present in adequate amounts, which is critical for therapeutic outcomes. Thus, the comparative nature of WV testing does not offer the same level of assurance regarding individual dosage unit potency as CU does.

Given these considerations, CU stands out as the more reliable measure for quality assurance in manufacturing solid dosage forms.