Oral dosage is the most commonly used and preferred method of drug administration due to its several advantages, including non-invasiveness, patient adherence, and ease of use. However, oral bioavailability can be influenced by several factors, such as drug solubility and mucosal permeability in the gastrointestinal tract, sometimes leading to poor and/or inconsistent absorption. In particular, low aqueous solubility presents a significant challenge in achieving adequate oral bioavailability and therapeutic effectiveness for many pharmaceutical compounds. Attempts to overcome these limitations have focused on deeper understanding of the physicochemical, biochemical, and biological barriers that limit overall drug bioavailability. To ensure better and stable pharmacokinetic behavior of orally administered drugs, various formulation strategies have been developed to enhance solubility, dissolution rate, membrane permeability, and overall oral bioavailability. This review article explores recent advancements in formulation techniques aimed at improving the biopharmaceutical properties of orally administered drugs. The challenges and development aspects of oral dosage forms are also addressed.

Bioavailability  /  Drug delivery system  /  Emulsion  /  Microenvironmental pH-modifier  /  Nanoparticles  /  Oral absorption  /  Poorly soluble drugs  /  Solid dispersion