Injection special injectable product formulations

Gas chromatography is commonly used to analyse mixtures for quantification. A wide variety of special detectors with adequate linear response ranges are available for quantification of various classes of compounds (cf. Table 4.14). Quantification by direct injection may be used to determine additives, residual monomers and solvents in product formulations, coated films, and solid materials [109]. On the other hand, reliable quantification by means of solid-injection PTV-GC, HS-GC and PyGC techniques is not always trivial. 

Cefuroxime is only poorly absorbed from the gastrointestinal tract and so was originally only an injectable product, but a commercially successful new orally-administered cerufoxime ester product has been developed which has created a new surge in sales. This acetoxyethyl pro-drag form of cefuroxime is rapidly hydrolysed in the brash-border mucosal epithehal cells of the duodenum and small intestine, but requires special formulation so as to ensure efficient dissolution following investigation. 

In several cases the special nature of a formulation will preclude dilution by an aqueous infusion fluid. Injectable products containing phenytoin, digoxin and diazepam may come into this category if they are formulated in a nonaqueous but water-miscible solvent (such as an alcohol-water mixture) or as a solubilised (e.g. micellar) preparation. Addition of the formulation to water may result in precipitation of the dmg, depending on the final concentration of the dmg and solvent. It has been suggested that precipitation of the relatively insoluble diazepam may account for the high (3.5%) incidence of thrombophlebitis which occurs when diazepam is given intravenously. 

The resin system developed with BP for Lucas is a special one, which delivers a high surface gloss with mechanical strength. If the (confidential) formulation is varied, the properties suffer. The compound formulation --glass content etc. and its application to headlights by injection moulding are protected by patents, which places the product in a strong commercial position. 

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