Drug delivery systems are methods or technologies used to administer a drug to achieve therapeutic effects. They include:

• Oral Delivery: Tablets, capsules, and oral suspensions.
• Topical Delivery: Creams, gels, and transdermal patches.
• Injectable Delivery: Solutions, suspensions, and implants.
• Inhalation Delivery: Aerosols and powders for inhalation.
• Biologic Delivery: Complex systems like monoclonal antibodies and gene therapies.