Virtually all marketed pharmaceutical preparations contain excipients; no finished drug product consists solely of the active pharmaceutical ingredient (API).
Oral Solid Dosage Forms (The Most Common Category)
Conventional tablets and capsules: Almost all contain fillers (such as starch, lactose, or microcrystalline cellulose), binders, disintegrants, and lubricants to facilitate formulation and ensure rapid drug release.
Enteric-coated, sustained-release, and controlled-release tablets: These incorporate additional coating materials or matrix-forming agents to achieve site-specific release or prolong the duration of therapeutic effect.
Chewable tablets and effervescent tablets: These utilize significant amounts of flavoring agents and effervescent acid-base systems to improve taste and the overall user experience.
Injectable Preparations (Subject to the Strictest Excipient Grade Requirements)
Small-volume parenterals and infusion solutions: These require injection-grade solvents (water for injection), pH adjusters, and osmotic pressure regulators; some formulations also include antioxidants or solubilizers.
Fat emulsions and drug-loaded emulsions: These employ specialized excipients, such as injection-grade medium-chain triglycerides and emulsifiers, which serve as carriers for lipophilic drugs.
Sterile powders for injection and microspheres: These incorporate lyophilization (freeze-drying) excipients or sustained-release carrier materials to ensure proper physical form and long-acting therapeutic effects.
Mucosal and Topical Preparations
Ophthalmic solutions and ointments: These utilize ophthalmic-grade antimicrobial agents, thickening agents, and pH buffers to minimize irritation and extend the drug's residence time on the ocular surface.
Ointments, creams, and gels: These contain oleaginous bases, emulsifiers, and penetration enhancers to facilitate the transdermal absorption of the drug.
Aerosols, nasal sprays, and inhalation powders: These utilize propellants, solubilizers, and dispersing agents to ensure that the drug is delivered to the respiratory tract with the appropriate particle size.
