Oral Solutions and Suspensions

The evaluation should include appearance (including formation of precipitate, clarity for solutions), color, odor, assay, degradation products, pH, preservative content, and microbial limits. 

In addition, for suspensions, redispersibility, rheological properties, and mean size and distribution of particles should be considered. After storage, samples of suspensions should be prepared for assay according to the recommended labeling (e.g., shake well before using ). 

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The different salts, esters, ethers, isomers, mixtures of isomers, complexes or derivatives of an active substance shall be considered to be the same active substance, unless they differ significantly in properties with regard to safety and/or efficacy, in which case additional safety and efficacy data are required. The same qualitative and quantitative composition only applies to the active ingredients. Differences in excipients will be accepted unless there is concern that they may substantially alter the safety or efficacy. The same pharmaceutical form must take into account both the form in which it is presented and the form in which it is administered. Various immediate-release oral forms, which would include tablets, capsules, oral solutions and suspensions, shall be considered the same pharmaceutical form for this purpose. 

Oral solutions and suspensions Appearance, precipitation, pH, color, odor, redispersibility (suspensions), and clarity (solutions)... 

Regulatory expectations for microbial bioburden for nonsterile pharmaceutical products are reviewed using the FDA guide to inspections of microbiological quality control laboratories [2], purified water systems [27], topical products [28], and oral solutions and suspensions [29]. 

In the guide to inspection of oral solutions and suspensions [29], it is stated that in some oral liquids microbiological contamination can present significant health hazard. For instance, microbiological contamination with gram-negative... 

U.S. Food and Drug Administration (FDA) (1994), Guide to inspection of oral solutions and suspensions, FDA, Rockville, MD. 

Oral Solutions and Suspensions Formation of precipitate, clarity for solutions, pH, viscosity, microbial bioburden, extractables, and polymorphic conversion when applicable. Additional tests for suspensions include redispersability, rheological properties, mean size, and distribution of particles. 

Powders for Oral Solutions and Suspensions Water content, reconstitution time, and reconstituted solutions and suspensions should be tested as above for oral solutions and suspensions. 

Low topical solutions and topical powders oral tablets and oral suspensions topical oral powders (hard and soft and lingual aerosols gelatin), capsules, oral solutions, and suspensions... 

Parabens are approved for use in oral solution and suspensions at a concentration of 0.015% to 0.2% w/v. Due to their low solubility, the sodium salts of parabens are often used in aqueous formulations. The parabens are most effective in the pH range of 2 to 6, and their antimicrobial activity decreases with increasing pH. Additionally, they are very unstable at pH 8 or above in solution. Methyl paraben has also demonstrated incompatibility with sorbitol and may show some discoloration in the presence of iron. The absorption of methylparaben by plastics has been reported with the amount absorbed being dependent upon the type of plastic and vehicle. However, no absorption has been reported for low density polyethylene (LDPE) or high density polyethylene (HDPE) containers. Certain coloring agents such as yellow iron oxide, ultramarine blue, and aluminum silicate can extensively absorb ethyl paraben in simple aqueous systems, thus reducing its preservative efficacy. 

Included in the FDA Inactive Ingredients Guide (oral solutions and suspensions rectal preparations). Included in the Canadian List of Acceptable Non-medicinal Ingredients. 

Tablets Capsules Emulsions Oral solutions and suspensions Metered dose inhalers Topical ophthalmic and otic preparations Parenterals...

Powders and granules for the preparation of oral solutions and suspensions generally conform to the definitions in the monographs on Oral powders or Granules as appropriate. They may contain excipients, in particular to facilitate dispersion or dissolution and to prevent caking. After dissolution or suspension, they comply with the requirements for oral solutions or oral suspensions, as appropriate. 

For the preparation of oral solutions and suspensions the following in-process controls may be appropriate ... 

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