Which statement best describes the fusion method in ointment preparation?

• A. Grinding solids into a fine powder at room temperature
• B. Using aqueous solvents to dissolve solids
• C. Heating ingredients to their melting points and mixing the molten masses
• D. Cold blending of waxes with oils

Answer: (C)

Fusion method relies on heating all solid components until they melt and then mixing the molten masses to form a uniform, homogeneous liquid that is allowed to cool into a smooth ointment. This approach ensures even distribution of lipophilic ingredients and waxes without using any solvent. Grinding at room temperature only reduces particle size; it doesn’t create a single molten mixture. Using aqueous solvents would introduce water and change the process entirely. Cold blending of waxes with oils combines parts at or near room temperature and doesn’t achieve the same thorough homogenization as melting and mixing the components. Thus, heating to melting points and blending the molten masses best describes the fusion method.