Soft gelatin capsules are a popular dosage form used to encapsulate various pharmaceutical and nutraceutical products. The capsules are made from a gelatin base that can be made elastic or plastic-like by adding certain excipients. Sorbitol is a polyol (sugar alcohol) that is commonly used as a plasticizer in the manufacturing of soft gelatin capsules. It helps to make the gelatin shell more flexible and elastic, improving its handling and durability. The addition of sorbitol helps in maintaining the integrity of the capsule, preventing it from becoming too brittle or too rigid, which can cause cracking or breaking.

**_ Povidone, also known as polyvinylpyrrolidone (PVP), is used as a binder in tablet formulations and as a solubilizing agent. It is not used as a plasticizer in the production of soft gelatin capsules. PEG is used as a plasticizer in various pharmaceutical formulations, but it is more commonly used in solid dosage forms and ointments rather than in soft gelatin capsules. It does not impart the same level of elasticity as sorbitol. HPMC is a cellulose derivative used as a film-former and thickening agent in pharmaceutical formulations. It is not typically used as a plasticizer for soft gelatin capsules but is more commonly used in controlled-release formulations and as a coating material. Among the given options, sorbitol is the correct plasticizer used to make the shells of soft gelatin capsules elastic or plastic-like. It ensures the capsules are flexible and durable, preventing issues such as cracking or breaking.