Polyethylene Glycol 600 (PEG-600) is a versatile excipient used in various pharmaceutical and cosmetic formulations. It acts as a solvent and co-solvent to dissolve active pharmaceutical ingredients (APIs) and excipients, aiding in the creation of solutions, suspensions, and emulsions. As a humectant, it helps retain moisture in formulations such as creams, ointments, and gels, ensuring stability and efficacy. PEG-600 also functions as a plasticizer, improving the flexibility and reducing the brittleness of films and coatings in tablets and capsules. It serves as an ointment base, compatible with a wide range of substances, facilitating the formation of semi-solid preparations. Additionally, PEG-600 is used as a lubricant in manufacturing processes and final dosage forms, reducing friction during tablet compression and capsule filling. Furthermore, it acts as a stabilizer, preventing the crystallization of components to maintain a homogeneous mixture essential for efficacy and safety.