Ascorbyl-6-palmitate

BP Ascorbyl palmitate PhEur Ascorbylis palmitas USPNF Ascorbyl palmitate 

L-Ascorbic acid 6-palmitate E304 3-oxo-L-gulofuranolactone 6-palmitate vitamin C palmitate. 

Ascorbyl palmitate is primarily used either alone or in combination with alpha tocopherol as a stabilizer for oils in oral pharmaceutical formulations and food products generally 0.05% w/v is used. It may also be used in oral and topical preparations as an antioxidant for drugs unstable to oxygen. The combination of ascorbyl palmitate with alpha tocopherol shows marked synergism, which increases the effect of the components and allows the amount used to be reduced. 

The solubility of ascorbyl palmitate in alcohol permits it to be used in nonaqueous and aqueous systems and emulsions. 

Ascorbyl palmitate is a practically odorless, white to yellowish powder. 

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L-Ascorbic acid biosynthesis in plants and animals as well as the chemical synthesis starts from D-glucose. The vitamin and its main derivatives, sodium ascorbate, calcium ascorbate, and ascorbyl palmitate, are officially recognized by regulatory agencies and included in compendia such as the United S fates Pharmacopeia/National Formula (USP/NF) and the Food Chemicals Codex (FCC). 

Specifications for ascorbic acid, sodium ascorbate, calcium ascorbate, and ascorbyl palmitate are found in the Umted States Pharmacopeia J National Formula ... 

To make ascorbic acid soluble in fats, it is reacted with fatty acids, such as palmitic acid, to form ascorbyl palmitate. This is used to prevent oxidation in fats and oils. 

Perricone NV (1993) The photoprotective and antiinflammatory effects of topical ascorbyl palmitate. J Ger Dermatol 1 5-10... 

Of these, only ascorbyl palmitate was effective. Butylated hydroxyanisole and a-tocopherol were not. 

It was found that when a-tocopherol was dispersed in the aqueous phase in absence of the oil, nitrite was readily destroyed. It was concluded that the reduced inhibition obtained with butylated hydroxyanisole and a-tocopherol was at least in part due to their isolation from the nitrite in water phase. On the other hand, the reducing portion of the ascorbyl palmitate molecule could be in the water phase at the oil/water interface. 

Evidence exists that the relative solubility of amines and inhibitors in heterogeneous oil-water systems could be decisive in formation of nitrosamines and blocking these reactions, Nitrosopyrrolidine formation in bacon predominates in the adipose tissue despite the fact that its precursor, proline, predominates in the lean tissue (5,6,7). Mottram and Patterson (8) partly attribute this phenomenon to the fact that the adipose tissue furnishes a medium in which nitrosation is favored, Massey, et al, (9) found that the presence of decane in a model heterogeneous system caused a 20-fold increase in rate of nitrosamine formation from lipophilic dihexylamine, but had no effect on nitrosation of hydrophilic pyrrolidine. Ascorbic acid in the presence of decane enhanced the synthesis of nitrosamines from lipophilic amines, but had no effect on nitrosation of pyrrolidine. The oil-soluble inhibitor ascorbyl palmitate had little influence on the formation of nitrosamines in the presence or absence of decane. 

Since a-tocopherol destroys nitrite in the system in absence of the oil phase, we may postulate that the ineffectiveness of these two oil soluble inhibitors resulted from their absence from the aqueous phase. Diethanolamine is miscible with water and presumably its nitrosation occurs in the aqueous phase. There is a significant difference in the solubility characteristics of ascorbyl palmitate. The reducing portion of the molecule is water soluble. Thus the ascorbate moiety may be in the aqueous phase while the fatty acid tails may lie within the oil globules. The a-tocopherol and the BHA may well be effective if they are dispersed in the aqueous phase after preparation of the emulsion. This will be investigated in future experiments. 

The selection of an appropriate antioxidant depends on factors such as stability, toxicity, efficiency, odor, taste, compatibility with other ingredients, and distribution phenomena between the two phases. Antioxidants that give protection primarily in the aqueous phase include sodium metabisulfite, ascorbic acid, thioglycerol, and cysteine hydrochloride. Oil-soluble antioxidants include lecithin, propyl gal-late, ascorbyl palmitate, and butylated hydroxytoluene. Vitamin E has also been used, but its virtue as a natural antioxidant has been the subject of some controversy. 

Tocopherols are not as effective as antioxidants as the synthetic antioxidants, e.g. BHA or BHT. The antioxidant effect of tocopherols is increased by mixing them with ascorbyl palmitate, ascorbic acid, lecithin or citric acid. Typical confectionery applications are the use of tocopherols with ascorbyl palmitate or lecithin or citric acid in the fat phase of toffees or caramels. Chewing gum base can be treated with a- and y-tocopherol to extend the shelf life. 

E 304 Fatty acid esters of ascorbic acid (i) Ascorbyl palmitate (ii) Ascorbyl stearate... 

E 304 esters of fatty acids with ascorbic acid (i) ascorbyl palmitate (ii) ascorbyl stearate quantum satis... 

E 304 L-ascorbyl palmitate foods including biscuits fat-containing cereals, 100 mg kg-1... 

For non-standardised products tocopherols, tocopherol acetate, ascorbic acid and its sodium and calcium salts, ascorbyl palmitate, ascorbyl stearate, eiythorbic acid and stannous chloride (max. 0.0015% calculated as tin) may be used according to good manufacturing practice. 

Ascorbic acid and its sodium salt Eiythorbic acid and its sodium salt Ascorbyl palmitate... 

Interest has been shown in using derivatives of ascorbic acid as antioxidants. One such compound is ascorbyl palmitate. In the structure of ascorbyl palmitate, the 2- and 3-positions are occupied by hydroxyl groups the 6-position contains the substituted fatty acid. Other derivatives, synthesized by Seib and associates were ascorbate-2 phosphate and ascorbate 2-triphosphate (27). Both of these compounds were reported to inhibit lipid oxidation in ground meat as measured by chemical means (2). Ascorbate-2-phosphate was also found to inhibit MFD in beef as measured by sensory means (2). The ascorbate-2-triphosphate was not tested as an inhibitor of MFD in this study, but... 

In view of the multiplicity of CYPs and the many possible botanical-drug interactions, highly efficient clinical study designs using CYP probe cocktails have been explored. Following successful application to St. John s wort, other botanicals that have been evaluated in this fashion include echinacea (42), saw palmetto (43), garlic (39), peppermint oil, and ascorbyl palmitate (44). The results are summarized in Table 1. Curbicin, a botanical... 

Dresser GK, Wacher V, Wong S, Wong HT, Bailey DG. Evaluation of peppermint oil and ascorbyl palmitate as inhibitors of cytochrome P4503A4 activity in vitro and in vivo. Clin Pharmacol Ther 2002 72 247-255. 

Sodium sulfite Ascorbyl palmitate Ethylenediamine tetraaceticacid (EDTA)... 

Sodium, potassium, and calcium salts of ascorbic acids are called ascorbates and are used as food preservatives. These salts are also used as vitamin supplements. Ascorbic acid is water-soluble and sensitive to light, heat, and air. It passes out of the body readily. To make ascorbic acid fat-soluble, it can be esterified. Esters of ascorbic acid and acids, such as palmitic acid to form ascorbyl palmitate and stearic acid to form ascorbic stearate, are used as antioxidants in food, pharmaceuticals, and cosmetics. 

Perennial and seasonal allergic rhinitis Promethazine hydrochloride Phenergan Ascorbyl palmitate, silicon dioxide, white wax, and cocoa butter... 

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