Oral Drug Delivery Systems: Introduction

Oral drug delivery is the most common route due to its convenience, cost-effectiveness, and high patient compliance. It enables precise formulation to ensure proper drug dosage and bioavailability. Patients prefer oral administration because it avoids injections and allows self-administration at home, improving adherence to medication regimens.

The choice of oral dosage form depends on drug solubility, stability, and the target absorption site in the digestive system. Drug properties guide whether tablets, capsules, liquids, or chewable formulations are most appropriate. Formulation scientists consider these factors to optimize therapeutic efficacy and ensure the drug reaches its intended site of action.

Coatings protect drugs from degradation and control where absorption occurs. Enteric-coated tablets prevent drug breakdown in the stomach, ensuring delivery to the intended absorption site in the small intestine. Some coatings enable modified release drug delivery systems, sustaining drug concentrations in the bloodstream and improving therapeutic outcomes while reducing dosing frequency.

Flavored liquids and dissolvable, dispersible, or chewable tablets are formulated to ease administration for children and elderly patients with swallowing difficulties. These formulations mask undesirable tastes and improve patient experience. Liquid and chewable forms provide flexible dosing options while maintaining accurate drug delivery for vulnerable populations.

Excipients are inactive ingredients that modify drug release profiles, enhance absorption, and protect drugs from degradation. Low-dose drugs like antihypertensives, anticonvulsants, and hormones are formulated into solid dosage forms using excipients for precise dosing and accurate administration. Excipients also mask taste and improve drug stability throughout the product's shelf life.

Nanoparticle-based formulations improve solubility and facilitate targeted delivery at absorption sites. Bioadhesive formulations use polymers that adhere to mucosal surfaces, prolong drug residence time, and enhance absorption. These innovations contribute to personalized medicine, allowing optimized drug regimens and improved patient outcomes across diverse populations.

Sustained-release formulations provide gradual drug release, reducing dosing frequency and improving patient adherence. They minimize plasma drug level fluctuations to reduce side effects while maintaining therapeutic efficacy. This approach enhances convenience and compliance, particularly for chronic conditions requiring long-term medication management.