Interesting pills

In daily life, do you find that most pills are white? Why is this? What causes some pills to appear in other colors? Today I will give you a brief scientific explanation.

Prevent and warn against spoilage

Many tablets are coated with sugar, which contains edible pigments. The pigments have a more or less light-shielding effect, which can stabilize the drug ingredients, especially those that are sensitive to light. For example, many capsules often contain colorants and light-shielding agents to improve drug stability. The sugar coating can effectively isolate the air, preventing the drug from deliquescing or undergoing chemical changes that affect the efficacy. It can also make the surface of the tablet smooth, preventing powder loss and adhesion. We can judge whether the drug is expired based on the change in the color of the tablet, such as when the bright color fades or changes color. If this happens, we should stop using it in time and consult a doctor or pharmacist. If the tablet itself is white, such as vitamin C, and the color of the tablet changes from white to yellow, we should suspect that it has expired and should not be taken again [1].

Distinguish between identification and reminder

From the perspective of doctors and patients: it can reduce the chance of taking the wrong medicine and improve the safety of medication. For example, many patients with chronic diseases and the elderly may need to take multiple medicines at the same time. Different colors can help distinguish different pills to avoid missing or taking the wrong pills.

From the perspective of pharmaceutical production: it can improve the identifiability of products during the production process and prevent mixed batches, mixed samples, and residues. The color of pills is a special symbol of many brands. For example, Viagra has left a deep impression on consumers because of its unique diamond shape and light blue appearance, and is known as the "little blue pill" [2]. Esomeprazole magnesium tablets (Nexium) for the treatment of gastroesophageal reflux have always been promoted as "purple pills". The role of color in pills is not just for appearance, but is actually more subtle. Studies have found that as long as the brand and the efficacy of the drug are linked, the placebo effect will increase people's belief in the efficacy of the drug and make them have emotional appeals to the product, thereby increasing consumers' dependence on the product and the brand reputation of the product [3].

Patents involved

Some drug manufacturers patent the appearance of their products (including size, shape, color, etc.) as a property under trademark law, called "trade dress," which allows people to recognize the specific drug name based on the appearance of the pill. Generic drug manufacturers are not allowed to copy the shape, color, and size of these brand name pills.

Especially for new drugs, manufacturers will try different drug names, colors, and shapes to avoid duplication with other drugs. They will also ask pharmacists for their opinions, such as what name/color/shape their new drug should be, and then ask professional designers to design the color and shape of the drug to highlight its product characteristics.

Different colors and shapes of medicines will give patients different feelings when taking them

1. The variety of colors of tablets and capsules for children can help reduce children’s fear of taking medicine. For example, some preparations for children are light yellow, orange, or even have animal patterns, making them look more like candy. This will increase the appeal of the medicine to children and increase children’s compliance with medication[4]. Although colorful tablets are beautiful, they should be placed out of children’s reach to prevent them from mistaking them for candy and taking them by mistake.

2. Used to cover up the bad taste of drugs. Some drugs taste bitter and difficult for patients to swallow. Pharmaceutical companies often apply a layer of colored sugar coating on the outside of the drugs to dilute the original bitter taste of the drugs, so that patients are more willing to take them.

* Research has found that red, yellow, and orange drugs produce stronger stimulant effects, while blue and green pills produce stronger sedative effects. In addition, green pills can significantly improve patients' anxiety, while yellow pills are more helpful for patients with depression. When faced with drugs of different colors, patients tend to prejudge that red and black drugs are more potent, while white drugs are weaker[5]. When taking the same drug in different colors, 14% of people think that pink drugs are sweeter than red, while yellow drugs are saltier. 11% of people think that white or blue pills taste bitter, while 10% think that orange drugs taste sour.

In addition, there are some Chinese patent medicine tablets, such as white tablets, which are used to relieve cough, resolve phlegm, relieve asthma, strengthen the stomach, and aid digestion [6], such as compound Chuanbei tablets, Chuanding tablets, Monkey mushroom tablets, multi-enzyme tablets, etc.; red tablets symbolize human blood and heart, so many sugar-coated tablets used to replenish blood, calm the mind, regulate menstruation, etc. are red. Such as Shengxue tablets, Buxin pills, etc.; yellow tablets are mostly antibacterial, anti-inflammatory, heat-clearing and detoxifying drugs, such as tetracycline tablets, antipyretic cold tablets, etc.; crimson (deep red) or coffee-colored tablets, such as liver-protecting and tonic drugs, are mostly coated with crimson sugar, giving people a sense of maturity and fitness, so fitness and nutrition drugs are also mostly made of crimson sugar, such as multivitamin tablets, brain-strengthening and kidney-tonifying tablets, etc.; blue tablets are divided into dark blue and light blue. The former is often seen in liver-soothing and gallbladder-promoting products, such as anti-inflammatory and gallbladder-promoting tablets, Daqing leaf tablets, etc.; the latter mostly have analgesic, sedative, and blood pressure-lowering effects. Such as Anshen tablets, Kunming Shanhaitang tablets, etc. [7].

[1] Jiang Jun. On the determination of drug appearance color and the control of colored impurities [J]. Qilu Pharmaceutical Affairs, 2009, 28(09): 537-538.

[2] Sun Yezhong. Analysis of factors affecting the color selection of coating materials in film coating technology [J]. China Pharmaceutical Industry, 2013, 22(16): 53-55.

[3]Carl Mroz, Annabel Bordmann.Colorcon leads the way to a bright, lustrous finish for food supplement tablets [J].Innovations in Food Technology, 2012 (5):54

[4] Cao Xia. What is the significance of drug color[N]. China Medical News, 2002-10-20

[5] Zhang Zhiqiang. Are colored pills prettier or more dangerous? [J]. Medical World, 2008(Z1):42-43. [6] Wang Zhuoyu. A brief discussion on the color of coated tablets [J]. Chinese Pharmacy, 2000(02):55.

[7] What does the color of the tablet coating indicate? [J]. Labor World, 1996(03):27.