Hydroxyzine is an antihistamine medication used to treat anxiety, pruritus, and other conditions. During the manufacturing process, trace amounts of impurities may be produced, which can affect the purity and potency of the drug. These impurities should be carefully monitored and controlled to ensure the safety and efficacy of the medication. Regulatory authorities require that pharmaceutical manufacturers perform rigorous testing to identify and quantify any impurities present in their products, and to establish acceptable limits for their presence.