Which of the following is NOT a route of administration for composite tablets?

• A. Ophthalmic
• B. Oral
• C. Sublingual
• D. Buccal

Answer: (A)

Ophthalmic administration is not used for composite tablets because these solid dosage forms are designed to release and absorb drugs through the oral cavity or gastrointestinal tract. Oral tablets are swallowed and rely on disintegration and dissolution in the GI tract, while sublingual and buccal tablets dissolve in the mouth to allow absorption through the oral mucosa. The eye, however, requires sterile, eye-specific dosage forms such as solutions, suspensions, gels, or ointments applied to the ocular surface. A tablet cannot be sterile for ocular use, would be hard to dose accurately for the eye, and its disintegration and absorption properties are not appropriate for ophthalmic delivery. Hence, the route not suitable for composite tablets is ophthalmic.