13 September 2008

UV Filter CreamSunscreen should ideally encompases the following characteristic :
  • Absorb the harmful UV radiation in the region of 280 to 400 nm. Using a single sunscreen filter is possible to produce a broad spectrum protection. That’s why combination two or more sunscreen filter may be necessary.
  • The individual filter should possess high molar extinction coefficients at their maximum wavelength. Values exceeding 25,000 would be best. This would provide the maximum possible protection for the dose of sunscreen used in the formulations.
  • UV filter should have great photostability and be photochemically inert. For example, Avobenzone is known to be photounstable in most formulations. If isomerization such as cis-trans or keto-enol is possible in the molecule, then the degradation quantum yields should be low, indicating that isomerization is reversible. Inoraganic particulates are commercially produced with the least amount of photochemical reactivity possible. Therefore, the type of mineral, the specific coating, and the type of dispersant must be carefully selected.
  • UV FilterUV filters also should have good solubility in emollients selected. Solid sunscreen such as the benzophenones, avobenzone, and camphor derivates require special technique and excipients to solubilize in formulations and ensure that they do not crystallize out on the skin. UV filter must remain dissolve and uniform throughout the formulation for an acceptable shelf life and coverage on the skin to ensure the stability of the sunscreen formulation.Solvent and excipients should not affect the molar extinction and the maximum wavelength.
  • For water resistant formulations, the sunscreen should be for the most part insoluble in water. Water soluble sunscreen will have a role to play in the sunscreen formulations, such as in hair preparations or when boosting the SPF required.
  • It should not be irritating to skin, eyes, comedogenic, sensitizing, or phototoxicUV Filter Product
  • It should be compatible with cosmetic ingredients and vehicles, as well as with packaging material, and easy to formulate and manufacture and have patent protection in the various filter combinations.
  • UV filter constitute a significant portion of the cosmetic formulation, sometimes as much as 15% of the formula, and this may impart moisturizing advantages.
  • Filters should not discolor the skin or clothing or produce off odors when applied to the skin or hair.
  • The UV filter should be chemically stable during long term storage, and be chemically inert to other cosmetic ingredients.
  • The ideal sunscreen should cost effective to use due to the high doses that must be used to produce high efficacy.
  • The UV filter should be approved worldwide by the official regulatory agencies with the fewest restriction on levels used or combinations.

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