Excipients colouring agents

In theory the constitution or quality of a manufacturer s drug may prove to be somewhat different in various countries, and manufacturers objecting to the parallel importation of their products have sometimes made his point in practice, however, any differences which exist relate only to particular excipients or colouring agents or to the language of the packaging text, ft is now in any case common practice for parallel products to be examined and approved by the regulatory authorities to establish the fact that they are indeed identical to the version imported officially. 

The intrinsic properties of the active substance are difficult to change, but the pharmacist can choose the right excipients and preparation techniques to overcome or decrease the impact of limitations. Although excipients should be pharmacologically inactive, they may cause adverse effects. The European Paediatric Formulation Initiative (EuPFI) project is considering the suitability of excipients for paediatric formulations. The results have been published in the STEP database [13]. For example many colouring agents have been associated with hypersensitivity and other adverse reactions. 

Safety issues to be considered are the exact equivalence of the products (especially for biologicals this may pose a problem) and the risk of allergy or intolerance for a specific excipient (e.g. colouring agents). 

Active substances Quality Excipients Application Raw material Labelling Pharmacopoeia FRC Solvents Surfactants Viscosity enhancers Preservatives Colouring agents Herbal... 

Adjuvants (density adjustment for flavouring oils in beverages, diluent for colours and other food additives, encapsulating agent, excipient) Adsorbants (decolourizing agent)... 

This sample should be examined visually for colour and the presence of tablet residues or excipients (often maize starch). The odour should be noted as tiiis may indicate the presence of alcohols, aldehydes, ketones, phenols, cyanide, ethchlorvynol, nicotine, etc. The following tests, details of which are given on p. 5, should be performed Trinder s test for salicylates, cresol-ammonia test for paracetamol, FPN reagent for phenothiazines, Fujiwara test for trichloro-compounds, and the diphenyl- nine test for oxidising agents. In addition, tiie Reinsch Test for heavy metals (p. 57) should be carried out, and a diluted, filtered extract examined by direct ultraviolet spectrophotometry for drugs with highyl values. 

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