Vitamin C remains the most requested active in premium skincare, yet it is also the most fragile. Pure ascorbic acid breaks down in water based formulas, darkens on the shelf, and loses potency long before a customer finishes the bottle. For overseas brands building a brightening line, this instability is not a small detail. It decides returns, reviews, and the credibility of the entire range.
The industry answer has been oil soluble derivatives, and the strongest candidate is tetrahexyldecyl ascorbate, known as THD. It dissolves directly in carrier oils, tolerates light far better than ascorbic acid, and needs no water to perform. Sealed inside a single dose softgel, the stability story becomes a selling point your sales team can demonstrate right on the shelf.
At CapsulesBiotech we fill vitamin C capsules for facial serum, eye serum, body lotion, face cream and hair oil lines, in either a 100 percent plant based shell or food grade gelatin. Here is how the format works, and what to specify before you request a quotation.
Why THD Suits an Anhydrous Fill
Ascorbic acid needs water to dissolve, which is exactly where it degrades. THD is already oil soluble, so it sits comfortably in squalane, jojoba or ester carriers with no emulsifiers and no preservatives. A softgel removes the remaining enemies, oxygen and light, because each shell seals one fresh dose away from air until the moment of use. THD also carries a silky skin feel that spreads well, so texture stays elegant even at meaningful use levels.
Matching Fill Volume to Your Line
Single dose sizing follows the application, not the other way round. Our filling lines cover the full range brand owners ask for:
- 0.2 to 0.35 ml for eye serum doses
- 0.35 to 0.5 ml for daily facial serum
- 0.5 to 0.8 ml for neck and chest care
- 0.8 to 1 ml for body oil applications
Shell Choice and Shelf Expectations
A transparent shell shows the warm golden color of the fill, which merchandises well in unboxing content, yet we still recommend an opaque or tinted shell for vitamin C projects. Blocking light keeps the color stable for the full shelf life. During sampling we agree on a color drift reference with you, so expectations are written down before mass production begins.
Positioning Claims That Stay Safe
THD supports a brightening, antioxidant led positioning when phrased as cosmetic appearance. Say it brightens the look of skin, never whitening, curing or repair language. Keep the claim set on the carton aligned with the formula documentation we supply, and the line can move through EU, US and Southeast Asia market registration without rework later.
Competitors selling water based vitamin C serums fight discoloration with dark glass, airless pumps and heavy preservative systems, and they still lose the battle within months. A sealed capsule ends that fight by design, which is why the single dose format keeps winning shelf space in the brightening category worldwide.
When you are ready to develop a vitamin C capsule line, send us your target market and positioning. Our team will respond with a formula direction, a recommended fill volume, and a production schedule that matches your launch window.
- Target market and planned retail tier
- Preferred shell type, plant based or gelatin
- Desired dose size and pieces per pack
- Carrier oil or fragrance preferences
From first sample to mass production, CapsulesBiotech keeps every dose of vitamin C sealed, measured and light free, the way this demanding active deserves.