Additives provide protection to solid dosage forms from atmospheric conditions, moisture protection to hygroscopic drugs, targeted delivery in intestine/colon or taste masking for mouth-dissolving tablets and for bitter drugs. For instance, a sweet tasting tablet goes down well without really troubling our taste buds. Colourful tablets make pills more interesting for younger patients and help people differentiate between medications. It may also be that the API needs a binder or a stabilizer.

The quantity of additives may vary depending on the dosage form, while each additive serves a different function. For example, binders hold ingredients together and prevent them from dispersing so that the digestive track is not afflicted. Lubricants are necessary to remove tablets from machines, whereas printing inks and dyes are required for colour coding. Additives also have an enormous impact on bioavailability of medicines.

Additives collectively constitute almost 90 percent of the final dosage form by weight and volume. It is important, therefore, the standards for additives and their manufacturing practices are clearly regulated in consideration of the overall safety of pharmaceutical products.

Advantages

• Additives make a drug easy to handle and provide a specific 'look' to a pill. Among hundreds of other uses, additives are important to give an agreeable flavour to the medicine.

• 'Throat coating' is needed to improve the aesthetics of a tablet by making it easier to swallow.

• Enteric coating' improves bioavailability and allows sustained release of active ingredients.

• Additives provide protection to solid dosage forms from atmospheric conditions, moisture protection to hygroscopic drugs, targeted delivery in intestine/colon or taste masking for mouth dissolving tablets and for bitter drugs.

• Additives improve manufacture, quality or performance of the drug product. Depending on the requirements, additives can provide taste masking of bitter actives, tailor release the profile, provide protection of the drug from the stomach or vice versa.

Challenges

The first prerequisite while choosing an additive is that it should be biologically inert and non-reactive as some of these 'add-ons' adversely affect the patient. Problems arise when patients change brands or switch from branded to generic drugs; e.g. patients show pulmonary difficulty along with abnormal drug metabolite concentration ratio after switching from branded drug, cordarone, to its generic form, amiodarone.

Anti-asthma drugs contain sulphites that may show reactions like breathing difficulties, chest tightening etc. Sulphites are present in many anti-inflammatory drugs that are used to treat diseases like arthritis.

Similarly, while dyes are the most common ingredients of any medication, dyes like sunset yellow are associated with gastric problems.

Adequate research and quality control can help avoid these pitfalls. Research should be done to assess long-term adverse reactions of additives and replace any relatively unsafe ones with safe and inert substances. There should be no 'minuses'-excipients should be inert as far as possible-if at all pharmaceutically enhancing the actions of the main medicine.

Although the manufacture of APIs should follow Good Manufacturing Practices (GMPs) imposed by national regulatory authorities, the manufacture of additives is generally not so stringently regulated. There are certain guidelines published by the International Pharmaceutical Excipient Council for GMP manufacture of additives. Incidents of poisoning have shown repeatedly that it is necessary to develop mandatory GMPs to govern manufacture of additives. It is possible to tackle adverse effects of additives if required precautions are taken. Companies that deal with additives have already taken steps to minimize possible side effects of additives.

Almost every type of industry requires colours and the pharma industry is no different. Food and pharma together constitute about five percent of colourant use and therefore constitute an important user group. According to the Global Industry Classification Standard (GICS), specialty chemical companies are those that primarily produce high value added chemicals used in the manufacture of a wide variety of products, including, but not limited to, fine chemicals, additives, advanced polymers, adhesives, sealant and specialty paints, pigments and coatings.

Globalization of supply chain in pharmaceutical industry is going to be a tough challenge for ensuring quality of pharmaceuticals in the years to come. Indian formulation producers import a large number of APIs and additives from China just because they are cheaper. It was to ensure the quality of imported drug materials.

Indian government had made registration of all imports of drugs and pharmaceuticals into the country compulsory from 1 April, 2003. Absence of a registration system has been resulting in import of large quantities of substandard drug materials into the country for some years. There is no quality assurance of APIs being imported into the country today.

Companies with niche and fundamental research strengths will thrive. The specialty industry is knowledge based and in order to survive in the global environment, Indian companies have realized that they have to become knowledge-based.