Oral liquids flavour

Solutions Suspensions Emulsions Solubilisates Oral liquids Syrup Flavour Acceptable daily intake Colour Taste Feeding mbe Preparation Formulation... 

The pH of an oral liquid is important for the flavour, solubility and stability of the active substance and for preservation. The preferred pH for an oral solution is between 5.5 and 7.5. A pH < 5.5 often tastes better, but may degrade the tooth enamel although the total amount of free acid plays a role as well [30]. A pH above 8 often gives an unpleasant taste. 

A flavouring agent includes the existing taste in a flavour that is experienced as less unpleasant. Apart fi-om a suitable flavour also a smell suiting the basic taste has to be added. For example, if an xmpleasant bitter or sour tasting oral liquid has a smell that suggests the bitter, respectively sour taste, the preparation will be experienced as less unpleasant. The colour may also play a part by arousing a particular taste. 

For children up to about 4 years sweet oral liquids with banana or raspberry essence are preferred [36]. A midazolam hydrochloride oral solution (Table 5.21) usually applied in the premedication of children before surgery or clinical diagnostics contains sucrose as sweetening agent and raspberry flavour, which is favoured by younger children. 

Syrups are a very commonly used form of sugars. They contain approximately 45-65 % of sugar, water and a preservative. Sometimes a flavouring is added. The preservative is most often methyl parahydroxybenzoate 0.1-0.15 %. Syrups can be very useful for improving the taste of oral liquid preparations and sometimes they can be used to stabilise a solubilisate of oil and polysorbate, e.g. in a vitamin A micellar solution (Table 23.12). 

Elixir are liquid, oral preparation of potent or nauseous medicaments, which are pleasantly flavoured and coloured with suitable agents. 

In France, it is the custom before a meal to partake of an aperitif, usually an aniseed-flavoured spirit called pastis. Pastis (e.g. Ricard , Pernod ) when it comes out of the bottle is a clear, light brown coloured solution of volatile oils from the seeds of the anise plant (Pimpinella anisum), which impart the characteristic aniseed flavour to the drink, dissolved in approximately 40% v/v ethanol. When a pastis is drunk, it is mixed with water and ice, whereupon the liquid becomes cloudy. This happens because the anise oils are hydrophobic, non-polar liquids and not very water-soluble. They are only held in solution by the high alcohol content of the drink. When the alcohol is diluted with water, the oils come out of solution and form an emulsion of oil droplets in the aqueous phase. This is what gives the drink its cloudy appearance. Oral solutions of anise oils have been used pharmaceutically for their carminative action and as an aid to digestion for many years, although it seems to this author preferable to consume anise oils in the form of a pastis, rather than in the form of a bottle of medicine. 

Oral powders are preparations consisting of solid, loose, dry particles of varying degrees of fineness. They contain one or more active substances, with or without excipients and, if necessary, colouring matter (...) and flavouring substances. They are generally administered in or with water or another suitable liquid. They are presented as single-dose or multidose preparations [6]. 

---