Oral liquids preparation methods

In one study by Hood et al., 282 of 1153 identified proteins were identified by at least 2 unique tryptic peptides from FFPE prostate cancer (PCa) tissue.9 According to the gene ontology classification of the proteins identified, -65% of proteins were predicted to be intracellular proteins, while -50% of the total human proteome is predicted to be located in the intracellular compartment. Additionally, 20% of the proteins identified in the PCa tissue were classified as membrane proteins, which is significantly less than the predicted 40% for the human proteome. This relative disparity is not unexpected, considering the Liquid Tissue sample preparation kit lacks specific protocols for membrane protein extraction. The Liquid Tissue method has also been used for proteomics studies of a variety of FFPE tissue samples, including pancreatic tumors,28 squamous cell carcinoma,4 and oral human papillomavirus lesions.27... 

The preparation of oral liquids generally follows the basic operations such as dissolving, mixing and dispersing described in Chap. 29. The method depends on the characteristics of the formulation solution, suspension, emulsion. This section discusses as well the increasing non-availability of the active substance as a raw material. 

Tetracycline hydrochloride dissolves partially in water and then degrades quickly. Moreover, the pH of such a solution is very low (about 2) which is too low for an oral liquid. By adding sodium citrate the pH is increased to about 6. Tetracycline precipitates finely divided and the dissolved fraction is as small as possible. This method can be used as well to prepare a cream containing tetracycline. 

Like crystallization, US also successfully assists the formation of extremely finely divided and uniform particles, which can be termed sonoprecipitation. This effect, which has not yet been used in analytical chemistry and might facilitate sample preparation in nephelometric or turbidimetric methods, has been widely exploited by the pharmaceutical industry to prepare liquid dispersions of drugs for oral or subcutaneous administration where extremely small particle sizes ensure stable suspensions of the drug and faster assimilation into the body. On a laboratory scale, US-assisted precipitation of magnesium carbonate in a model system has been studied [65]. 

A rapid, simple, and specific TLC method has been developed for the estimation of panthenol and pantothenic acid in pharmaceutical preparations containing other vitamins, amino acids, symps, enzymes, etc. " The vitamin was extracted with ethanol (from tablets and capsules) or benzyl alcohol (from liquid oral preparations) and isolated from other ingredients by TLC on silica gel 60 plates with 2-propanol-water (85 15 vol/vol) as a solvent. p-Alanine (panthothenate) or p-alanol (panthenol) was liberated by heating for 20 min at 160°C. The liberated amines were visualized with the ninhydrin reaction and estimated by spectrodensitometry at 490 nm. Recoveries for panthenol and pantothenic acid were 99.8 2.25% and 100.2 1.7%, respectively. 

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