Many medications commonly taken by mouth come in the form of coated tablets. Understanding what “coated” means is helpful for proper use, as the coating serves several purposes. These outer layers play a significant role in how the medication works within the body.
What a Coated Tablet Is
A coated tablet is a solid medication covered with a thin, outer layer, typically made of a polymer or other specialized substance. This protective film is applied to the tablet’s core and enhances its physical characteristics, helping the active ingredients function as intended.
Why Tablets Are Coated
Pharmaceutical companies apply coatings to tablets to improve the medication’s effectiveness, stability, and patient experience. Coatings mask unpleasant tastes or odors, making tablets more palatable and easier to take. They also protect the active drug from environmental factors like moisture, light, and oxygen, which can degrade the medication.
Coatings improve the tablet’s appearance, often giving it a specific color or shape for brand identification and to prevent medication errors. A smooth coating can make a tablet easier to swallow by reducing friction. Coatings also control where and when the medication is released in the body, ensuring it reaches the intended site of action or is absorbed over a specific period.
Common Types of Coatings
Different types of coatings are employed depending on the specific needs of the medication and its intended action.
Film Coatings
Film coatings are thin, polymer-based layers, widely used for protection, taste masking, and ease of swallowing. They can also be designed to control drug release.
Sugar Coatings
Sugar coatings, a traditional method, involve applying multiple layers of sugar syrup to create a thick, sweet, and often glossy outer shell. Their main function is to mask bitter tastes and improve aesthetic appeal, especially for children’s medications. However, sugar coating is more time-consuming and can significantly increase the tablet’s size and weight.
Enteric Coatings
Enteric coatings are designed to resist the acidic environment of the stomach. These coatings do not dissolve in the stomach’s low pH but break down in the higher pH of the small intestine. This protects drugs that would otherwise be degraded by stomach acid or prevents irritation of the stomach lining, ensuring the drug is released where it can be properly absorbed.
Extended-Release or Controlled-Release Coatings
Extended-release or controlled-release coatings are formulated to release medication slowly over an extended period. This allows for a steady drug concentration in the bloodstream, reducing dosing frequency and potentially minimizing side effects. These coatings often utilize polymers that control the tablet’s dissolution rate, ensuring a prolonged therapeutic effect.
Patient Guidance for Coated Tablets
To ensure the effectiveness and safety of coated tablets, patients should follow specific administration guidance. Do not crush, break, or chew coated tablets unless explicitly instructed by a healthcare professional. Altering the tablet compromises the integrity of the coating, which is integral to its design.
For example, crushing an enteric-coated tablet can expose the medication to stomach acid, potentially causing it to degrade or irritate the stomach lining. Modifying an extended-release tablet can cause the entire dose to be released too quickly, leading to a sudden high concentration of the drug and increased risk of side effects. This rapid release can also mean the medication wears off sooner than intended. Always swallow coated tablets whole with water, as directed on the label or by a pharmacist. If swallowing a whole tablet is difficult, consult a doctor or pharmacist for alternative forms or instructions.