Lactic acid pharmaceutical grade

The fermentation-derived food-grade product is sold in 50, 80, and 88% concentrations the other grades are available in 50 and 88% concentrations. The food-grade product meets the Vood Chemicals Codex III and the pharmaceutical grade meets the FCC and the United States Pharmacopoeia XK specifications (7). Other lactic acid derivatives such as salts and esters are also available in weU-estabhshed product specifications. Standard analytical methods such as titration and Hquid chromatography can be used to determine lactic acid, and other gravimetric and specific tests are used to detect impurities for the product specifications. A standard titration method neutralizes the acid with sodium hydroxide and then back-titrates the acid. An older standard quantitative method for determination of lactic acid was based on oxidation by potassium permanganate to acetaldehyde, which is absorbed in sodium bisulfite and titrated iodometricaHy. 

Calcium lactate (CH3-CH(OH)-COO)2Ca 5H2O) is produced as an intermediate in the production of lactic acid by the reaction of slaked lime with raw lactic acid. It acts as a protein plasticiser (coagulant) and is used as an egg extender and foaming agent. It is also used in pharmaceuticals as a source of calcium [31.17], and as a buffer and source of calcium in bread. Its production requires food-grade slaked lime (e.g., [31.30] and Table 31.2). 

PURAC has been producing pharmaceutical-grade lactic acid based polymers for medical applications during the last 30 years. These medical applications (e.g., sutures, bone screws) are not the focus of this chapter, which covers only the large-scale industrial applications of PLA. In 2008, PURAC started a d-LA program and produced L-lactide and D-lactide for its PLA partners, such as Synbra. Synbra plans to introduce small volumes of expandable PLA (BioFoam ) to extend its range of expanded polystyrene (PS)-based foam products, before building a 50,000 ton per year expanded-PLA production facility (Schut 2008). 

The pharmaceutical grade of lactic acid is sold at US 1000—1500 per ton while the industrial grades can be 20% less expensive depending on the area of apphcation. Many of the new lactic acid production facilities in China have yet to prove their feasibility in the short term due to the maturity of the implementation of the high efficiency fermentation process as well as the local market demands of PLA. Nevertheless, the multi-applications of LA will maintain its market interest on a long term basis. 

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