Soft Gelatin Capsules were developed in the 19th century to mask the unpleasant taste and odor of drug substances. After then, many improvements have been made with respect to the production of these soft capsules. In the pharmaceutical field, the soft gel dosage forms are increasingly being preferred. Technologically with soft gel, content uniformity of low-dose drugs has been achieved and also has consumer preference as is easy to swallow. Advances have recently been made in the area of developing liquid and semi-solid formulations in a soft gelatin capsule to address particular bio-performance issues.
The soft gel dosage form, therefore, offers several advantages over other oral dosage forms, such as delivering a liquid matrix designed to solubilize rapidly. This improves the oral bioavailability of poorly soluble compounds. Delivery of low and ultra-low doses of a compound using soft gel also ensures decreased plasma variability. However, due to the dynamic nature of the soft gel dosage form, its development and shelf-life stability optimization are challenging. This has led to the commercial pharmaceutical and nutraceutical industries opting for the development of alternative shell-forming materials instead of the traditional capsule shell material gelatin.
This review discusses the establishment and the ongoing development of the manufacturing technology for liquid fill capsules with a focus on soft gelatin capsules formulation in oral administration. Also considers the various pharmaceutical applications and recent patents on soft gelatin capsules