Ascorbic acid incompatibilities

Bleomycin Bleomycin is incompatible and loses its potency if it is administered with solutions of benzylpenicillin sodium, carbenicillin, cephazolin or cephalothin sodium, hydrocortisone sodium succinate, mitomycin, methotrexate, nafcillin sodium, aminophylline, ascorbic acid, terbutaline, divalent and trivalent cations (especially copper), compounds containing sulfhydryl groups, and precipitation by hydrophobic anions, essential amino acids, riboflavine, dexamethasone, and frusemide. 

Ionic liquids based on salts of alkylimida-zoles and pyridines have been used for the synthesis of esters of ascorbic acid and other sugars on the laboratory scale and show particular advantage in their ability to dissolve otherwise incompatible substrates. One of the key features of these solvents is their extremely low vapor pressures and excellent ability to dissolve both polar and nonpolar materials. Reactions can be run under vacuum allowing the removal of volatile byproducts such as water and enable one to... 

Multi-layered tablets A multilayered tablet consists of several different granulations compressed on top of each other to form a single tablet. They may also be bi-layer when incompatible drug substances are used, e.g., phenylephedrine HCl in one layer and ascorbic acid and paracetamol in another. 

Some antioxidants possess antimicrobial properties, such as propyl gallate and butylated hydroxy anisole, which are somewhat effective against bacteria. Butylated hydroxy toluene has demonstrated some antiviral activity. Compatibility of antioxidants with the drug, packaging system and the body should be studied carefully. For example, tocopherols may be absorbed onto plastics ascorbic acid is incompatible with alkalis, heavy metals, and oxidizing materials such as phenylephrine, and sodium nitrite and propyl gallate forms complexes with metal ions such as sodium, potassium and iron. 

Incompatible with alkalis, heavy metal ions, especially copper and iron, oxidizing materials, methenamine, phenylephrine hydrochloride, pyrilamine maleate, salicylamide, sodium nitrite, sodium salicylate, theobromine salicylate, and picot-amide. Additionally, ascorbic acid has been found to interfere with certain colorimetric assays by reducing the intensity of the color produced. ... 

Incompatibilities poorly compatible with citric acid and saccharose solutions. Incompatible with ascorbic acid, gelatin, glucose, lactose, oxidizing agents, and saturated sodium bicarbonate solution. 

Sodium starch glycolate is incompatible with ascorbic acid/ ... 

The results shown in Fig. 44 demonstrate clearly that reports of incompatibility of povidone with ascorbic acid in a number of publications are based on misinterpretations or the use of inappropriate methods. 

Crystals from aq ethanol, mp 206°. Slightly sol in water, chloroform. Sol in acetone, methanol. DMF, aq solns above pH 8.0. Less sol in ethanol. Pharmaceut. Incompat Calcium gluconate, ascorbic acid, tetracyclines, urea, epinephrine. LDga orally in female, male rats 2600, 2820 mg/kg (Goldenthal). 

Hygroscopic, dark red crystals. When exposed to air, may absorb about 12% water. The hydrated crystals are stable to air. Darkens at 210-220 . Not melted at 300 . [a] — 59 9" (dil aq soln). Absorption max (water) 278, 361. 550 nm (A12, 115. 204, 64). Odorless and tasteless. One gram dissolves in about 80 ml water. Aq solns are neutral, maximum stability in the pH range 4.5-5. Solns in this pH range can be autoclaved for 20 min at 120 . Soluble in ale. Insol In acetone, CHCl3, ether. Aq solns decomp in the presence of acacia, aldehydes, ascorbic acid, ferrous gluconate, ferrous sulfate, vanillin are stabilized hy the addn of ammonium sulfate. Talc has a tenacious affinity for vitamin B1t although this is not an incompatibility, it precludes the use of talc as a filter aid or lubricant for tablets, particularly in view of possible assay difficulties. 

If the reaction is incompatible with a peroxo species, molecular oxygen in presence of a chemical reductant (such as ascorbic or dihydroxyfumaric acid) may be used as oxidant [1353, 1354]. 

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