In topical formulations like creams, lotions and gels, stabilisers can be antioxidants and chelating agents. The stabilisers are added to the formulation to prevent or minimize degradation of sensitive API. In softgel capsules, stabilisers help prevent or minimize sticking, tacking, softening and premature dissolution of the capsule shell. They also minimise oxidation or degradation of the active ingredient fill or gelatin shell.

Antioxidants for softgel capsules

• Tocopherols (Vitamin E)
• 
  Butylated hydroxytoluene
• 
  Hydroquinone and tertbutyl hydroquinone
• 
  Dithiothreitol
• 
  Thiourea
• 
  Sodium thiosulphate
• 
  Thioglycolic acid
• 
  Acetyl cysteine

Chelating agent for softgel capsules

• Edetate Sodium
• 
  Edetate Disodium
• 
  Edetate Calcium Disodium
• 
  Sodium hexametaphosphate
• 
  8-hydroxyquinoline
• 
  Phytic acid