Liquid dosage forms excipients

If a liquid dosage form of a medication exists, it would seem rational to use this dosage form for administration through a feeding tube. Although such a decision may decrease the potential for tube clogging, it may in some instances decrease tolerability of the medication administration. Sorbitol is an excipient found in many liquid medications in amounts sufficient to cause diarrhea. If diarrhea secondary to sorbitol in a liquid medication is suspected in a patient on EN, contact with the manufacturer to ascertain sorbitol content may be necessary. 

It should again be emphasized that at the onset of a new drug program, there are only small amounts of drug substance at hand. One of the first tasks for the preformulation scientist is to establish the framework within which the first clinical batches can be formulated. To this end it is important to know with which common excipients the drug is compatible. Below, the distinction will be made between solid and liquid dosage forms. 

A variety of different artificial sweeteners have been approved for use in oral liquid dosage forms by the FDA. One general characteristic for artificial sweeteners is their very high sweetness compare to sucrose. This also results in a much lower concentration needed in the formulation, which can lower the cost and/or risk of incompatibility with the drug or other excipients. Additionally, a sugar-free formulation... 

It is essential to understand how and when the polymorphs of drug substance in oral liquid dosage forms and suspensions can be controlled. One approach to study this phenomenon is to seed the formulation with a small amount of a known polymorphic crystal (other than what is used for the product), which is a common practice to rapidly determine what effect this may have on long-term storage. From these types of studies, the appropriate excipients can be used to preserve the specific polymorphic form desired. However, even when the drug in its crystalline form is studied extensively, there are cases when a previously unknown polymorph may be formed in solution and lead to precipitation (14). 

Stewart and Tucker assert that hydrolysis is affected by pH, buffer salts, ionic strength, solvent, and other additives such as complexing agents, surfactants, and excipients, and each of these factors is discussed in some detail. Waterman et al. (31) provide a comprehensive treatment of hydrolysis as it relates to pharmaceuticals, with thorough discussions of mechanisms, formulation considerations, pH, ionic strength, buffers, solid-state considerations, hydrolysis of lyophiles, liquid dosage forms, packaging, etc. 

Solutions. For oral solutions, elixirs, syrups, tinctures, or other solubilized forms, in vivo BA and/or BE can be waived [21 CFR 320.22(b) (3) (i)]. Generally, in vivo BE studies are waived for solutions on the assumptions that release of the drug substance from the drug product is self-evident and that the solutions do not contain any excipient that significantly affects drug absorption [21 CFR 320.22(b)(3) (iii) ]. However, there are certain excipients, such as sorbitol or mannitol, that can reduce the BA of drugs with low intestinal permeability in amounts sometimes used in oral liquid dosage forms. 

Non-phenothiazines, such as haloperidol and loxitane, cause fewer urticarial reactions. As with any other class of drug, patients may be allergic to excipients in various tablet or capsule forms, or to preservatives, for example methylparabens in liquid dosage forms (522). 

During the development of a liquid dosage form of development compound C, it was observed that the solution changed color from slight yellow (initial color due to components in the formulation) to brown. What caused the change in color was the obvious question From one or more of the excipients which have slight yellow color or is it from the degradation product(s) of the... 

Purified drug substances are mixed with excipients into finished dosage forms sohds, liquids, parenterals, inhalants, and ointments and creams, then packaged and labeled and shipped for distribution. 

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