Abstract: Soft gelatin encapsulation, a new concept in the presentation of drug and food ingredients offers many benefits including segment control, elimination of taint problems during manufacture, extended shelf-life of product, and convenience of use. Soft gelatin capsules (SGC) is the current buzzword in the Pharma industry in recent years. The purpose of this review was to compile the recent literature with special focus on the advances of soft gelatin capsule and recent developments of SGC. This review also summarizes the in vitro and in vivo studies to evaluate the performance and applications of these systems. Soft gelatin capsule formulations are becoming more popular in recent years. These formulations can mask odor and unpleasant taste, and are easy to swallow. They are suitable for encapsulation of lipid solutions, suspensions, or paste-like formulations, making them a useful option when formulating poorly water-soluble drugs. The commercial pharmaceutical and nutraceutical markets have driven the development of alternative shell forming materials for the traditional capsule shell material gelatin. The on-going establishment and further development of the manufacturing technology for liquid fill capsules have provided a base for certain new applications for oral drug delivery, especially for lipid-based systems. A review of the US patent activity over the past decades reveals an improved sign of patent activity distinctively related to the softgel technology.
Soft gelatin capsules1 (referred to as soft elastic gelatin capsules, liquid gels or softgels) are a unique drug delivery system that can provide distinct advantages over traditional dosage forms such as tablets, hard gelatin capsules and liquids. However due to economic, technical and patent constraints there are relatively a few manufacturers of softgels in the world. Softgel is a hermetically sealed, one-piece capsule with a liquid or semisolid fill. The softgel consists of two major components, the gelatin shell and the fill. In the finished product gelatin shell is primarily composed of gelatin, plasticizer and water. The fill material can include a wide variety of vehicles and can either be a solution or a suspension. Softgels may be coated with suitable exterior coating agents such as Cellulose acetate phthalate (CAP) to obtain enteric release of encapsulated material. The standard softgel shape of oral pharmaceutical products is oval, oblong and round, though softgels can be manufactured in many shapes.
Soft gelatin capsules generally contain the drug in a non aqueous solution or suspension. The vehicle may be water immiscible liquid, such as PEG, and non ionic surface active agent, such as Polysorbate 80. Hydrophobic drugs dissolved in a lipophilic solvent such as vegetable oil would generally demonstrate poor bioavailability compared to the same drug given as a powdered solid, suspension or hard gelatin capsules. However, a drug dissolved or dispersed in a water miscible solvent may have better bioavailability than a compressed tablet of the same drug.