Which of the following is a method used to enhance the efficacy of Ketoconazole?

Applying ketoconazole to intact skin can enhance its efficacy because the skin is better able to absorb the medication in that state. Intact skin provides a barrier that, when disrupted, can lead to increased absorption and therefore more effective treatment of fungal infections.

In contrast, combining ketoconazole with steroids or antibiotics does not inherently enhance its antifungal properties. While there are scenarios where steroids may be used to reduce inflammation in certain conditions, they could potentially impair the antifungal effect by affecting the local immune response. Similarly, antibiotics do not directly influence the action of ketoconazole against fungi, as they target bacteria instead.

Thus, selecting the method that focuses on the application of ketoconazole to intact skin supports its intended antifungal action more effectively than the other methods mentioned.