Oral liquids emulsions

Ghosh LK, Ghosh NC, Thakur RS, Pal M, Gupta BK. 1997. Design and evaluation of controlled-release W/O/W multiple-emulsion oral liquid delivery system of chlorpheniramine maleate. Drug Dev Ind Pharm 23 1131-1134. 

Part IC Specific requirements for manufacture of oral liquids (syrups, elixirs, emulsions, and suspensions)... 

Liquid medicines generally include oral liquids, suspensions, emulsions, inhalations, nasal solutions and suspensions, topical semisolids and topical liquids, ophthalmics, and parenterals. There are numerous excipients used for liquid... 

Oral liquid and semisolid formulations containing water as part of the vehicle may be prone to microbial spoilage in the absence of a preservative. In the case of pharmaceutical creams, these are usually oil-in-water emulsions stabilized using a surfactant. Phenolic preservatives, e.g., parabens esters, are inactivated in the presence of nonionic surfactants, and this detrimental interaction can have serious consequences for preservation of the product (20). 

Liquids and semisolids. Include oral liquids, injectable, aqueous, and oil-based liquids, emulsions, suspensions, dispersions, solutions, drops, lotions, creams, ointments, pastes, gels, liniments, aerosols and foams, suppositories, and pessaries. 

Oral liquid or liquid emulsion Docusate (generic, Colace, others)... 

The properties of the active substance dominate and often restrict the choice of the type of oral liquid. Oral liquids are classified according to their physical properties as solutions, suspensions, emulsions and solubilisates. Solutions and suspensions are treated in depth because they are most often dealt with in daily practice. 

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

Different oral liquid dosage forms offer the possibility to adjust the dosage form optimally to the requirements. The options are solutions, suspensions, emulsions or solubilisates. The flow scheme in Fig. 5.1 shows a route to the oral liquid form that is to be preferred due to the qualities of the active substance, particularly solubility, stability and taste. The required concentration influences the choice as well. 

The main choice will be between an oral solution and an oral suspension. For some active substances an emulsion or solubilisate is the appropriate form. However in some cases (e.g. because of an intermediate solubility of the active substance) the pharmacist will have no other option than to dispense an oral solid dosage form and instruct the patient how to manipulate it safely (see Sect. 37.6.2). Proper consideration of the options may prevent formulation mistakes with probably severe consequences. This especially applies to the unreflected use of suspending bases for rendering an oral solid into an oral liquid. 

Water supports the growth of micro-organisms, therefore oral aqueous solutions, suspensions, emulsions and solubilisates in multidose containers should be preserved. Preservatives may be used for that purpose as well as excipients with preservative properties, such as propylene glycol. See Sect. 23.8 for extensive information on preservatives. Table 5.18 summarises preservatives with properties especially relevant for oral liquids. 

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. 

For the small scale preparation of oral emulsions the liquid active substance is added to base gel. The base gel can be... 

Sorbic acid is mainly used in cutaneous preparations and in oral liquid preparations. Because of the favourable oil-water partition coefficient it is suitable for formulating hydrophilic creams, emulsions and micellar solutions for oral use. For this reason it is preferred to methyl parahydroxybenzoate in these preparations. 

Oral liquid preparations oral solutions, suspensions and emulsions, drops for oral use... 

Fluids that are portioned out in a pharmacy usually are solutions for external use and oral liquids. However, emulsions, suspensions and light viscous fluids are also being portioned out with dispensers or filling apparatus. Apportioning of suspensions and emulsions always should be executed under continuous stirring. 

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