A generic drug  (or generics in plural) is a drug defined as "a drug product that is comparable to a brand/reference listed drug product in dosage form, strength, quality and performance characteristics, and intended use." It has also been defined as a term referring to any drug marketed under its chemical name without advertising or to the chemical makeup of a drug rather than to the advertised brand name under which the drug is sold.

Mostly, reverse engineering (reverse or back engineering, is the processes of extracting knowledge or design information from anything man-made and re-producing it or reproducing anything based on the extracted information. The process often involves disassembling something - a mechanical device, electronic component, computer program, or biological, chemical, or organic matter- and analyzing its components and workings in detail) is used to develop bio-equivalent versions to existing drugs. Therefore, generic manufacturers do not incur the cost of drug discovery. They also do not bear the burden of proving the safety and efficacy of the drugs through clinical trials, since these trials have already been conducted by the brand name company.

Although they may not be associated with a particular company, generic drugs are subject to the regulations of the governments of countries where they are dispensed. Generic drugs are labeled with the name of the manufacturer and the adopted name (nonproprietary name) of the drug.

A generic drug must contain the same active ingredients as the original formulation.  Generic drugs must be identical or within an acceptable bio-equivalent (  two products are said to be bio-equivalent when they would be expected to be, for all intents and purposes, the same)  range to the brand-name counterpart. By extension, therefore, generics are considered identical in dose, strength, route of administration, safety, efficacy, and intended use. In most cases, generic products are available once the patent protections afforded to the original developer have expired.

Some say Generic drugs are in general less effective than the original formulation due to a weaker placebo effect and a stronger nocebo effect ( but these effects are just psychological according to some experts and are not real).  The opinions (not facts) differ from place to place and person to person. The entire medical fraternity – doctors, chemists, pharmaceutical reps, etc. - is polarized on this issue. Some of them say that they are as good as branded ones while others feel that they are of poorer quality. Doctors and chemists have the impression that they are less effective. In fact some doctors avoid prescribing generic drugs as far as possible and even go to the extent of handing out free samples of branded drugs to patients who can’t afford branded medicines. Doctors also aren’t aware about their availability due to lack of advertising and marketing here. On the other hand drug companies  who manufacture these medicines say that there is no difference in quality and a generic drug was as good as a branded one.

The truth is if a drug is manufactured using reverse engineering technique, following all the quality control procedures, there shouldn't be any difference between generic drugs and their branded counterparts.

When generic products become available, the market competition often leads to substantially lower prices for both the original brand name product and the generic forms. The time it takes a generic drug to appear on the market varies. In most countries of the world, patents give 20 years of protection. However, many countries/regions, e.g. the European Union and the USA may grant up to 5 years of additional protection for drugs ("patent term restoration") if manufactures meet specific goals such as conducting clinical studies for pediatric patients. Manufacturers, wholesalers, insurers, and drugstores can each increase prices at various stages of production and distribution.

Generic drugs are usually sold for significantly lower prices than their branded equivalents. One reason for the relatively low price of generic medicines is that competition increases among producers when drugs no longer are protected by patents. Companies incur fewer costs in creating generic drugs (only the cost to manufacture, rather than the entire cost of development and testing) and are therefore able to maintain profitability at a lower price. The prices are low enough for users in many less-prosperous countries to afford them.

India's the global  leader in the generic market with Indian drugs popular in Africa and other emerging markets. They are drugs which have the same chemical composition as branded drugs are and sold under their chemical name. For example Paracetamol , a painkiller, is the generic name for branded drugs like  Crocin and Calpol. The drug market situation is a little different in India than the USA or other developed nations.  In the USA, when a new drug is launched only the company that holds the FDA patent are legally allowed to sell the drug , thus giving them market monopoly.  In India, however, there were no patent laws till 2005 which meant that anyone could replicate any drug in India without legal ramifications. This led to the trend of branded generic drugs which has 99.5% of the country’s generic drug share. Generic drugs are sold everywhere in India including your local chemist. To buy them one simply has to ask for generic version of a branded drug though they don’t have them for all medicines.

And wouldn't  multinational drug companies complain when they have to sell their branded drugs for the same rates India is quoting because of the competition? And they come up with several silly reasons like, for example, generic drugs are not very potent. The people who run these companies also complain that they spend millions on drug research but Indian generic drug producers are just copying their formulas and selling them for lower rates reducing their profit margins.

The results of a 2014 academic study by a team of researchers from the University of Maryland, the University of Ottawa, and the American Enterprise Institute, a conservative Washington, D.C., think tank, paint a very bad picture of generic drugs. The researchers tested samples of antibiotic and tuberculosis drugs labeled “made in India” and sold in India, Africa, and other non-African middle-income countries. They found that 10.9 percent of the products were of poor quality — that is, they either contained none or less than the required dosage of active pharmaceutical ingredients. Of this 10.9 percent, 7 percent contained less than the required dosage of active ingredients, while 3.9 percent were duds without any of the necessary active ingredients. Drugs without or with less than the required pharmaceutical ingredients will be ineffective, and therefore potentially harmful since they won’t treat the condition they’re meant to address. What’s more, poor-quality drugs were more likely to show up in Africa than in India or other middle-income markets. While some of this difference could be due to counterfeit drugs and poor storage conditions, the authors of the study claim that a more plausible explanation is that Indian companies are directing lower-quality drugs to the African market.

Low-cost Indian generics also continue to draw the ire of advanced economies like Canada, whose socialized medical system is trying to cut costs by importing cheaper drugs from India. Currently, some 5 percent of generic prescriptions in Canada are filled by drugs made in India. Meanwhile, in the United States, a whopping 40 percent of over-the-counter and generic drugs consumed are made by India’s pharmaceutical companies.

In 2008 the US FDA opened an office in New Delhi to ensure the safety of food and medical exports from India to the United States, and partner with Indian regulators to beef up their capacity on things like clinical trials and production facility inspections. Clearly this shows American authorities don’t have a lot of confidence in their Indian counterparts.

But  Doctors Without Borders/Médecins Sans Frontières (MSF), WHO and other United Nations agencies,  all the major donors and leading international treatment providers, like the Global Fund, PEPFAR, UNITAID, and UNICEF, all rely on quality and  affordable generic drugs for the programs they support in several poor and developing countries. They say when funding for global health programs is shrinking, it’s more important than ever to keep the flow of these affordable drugs going.

Many of the AIDS drugs doctors use right now to treat people with HIV are patented in many countries. But international trade rules required India to start granting patents on pharmaceutical products only after 2005. Until that time, Indian companies were able to manufacture generic versions that competed in price not only with brand name companies but also amongst themselves to bring down the prices of AIDS drugs drastically. This is what allowed the price of treatment to drop from over US$10,000 ten years ago to less than US$80 today.

It has also been possible for the Indian generic drug companies to create fixed-dose combination pills of these generic antiretrovirals—essentially two or three pills in one—that have been hugely influential in simplifying AIDS treatment and making treatment more practical in developing countries where MSF works. Imagine, one can offer a patient one pill once a day rather than a handful to be taken at different times of day.  Some of these fixed-dose combinations don’t even exist in rich countries precisely because of the patent barriers that exist there. In 2005, India put in place a patent law—fortunately it’s a law that supports public health objectives, so the result has been that India's generic manufacturers have had some space to continue producing affordable and effective medicines. But the problem ahead of us is that many of the newer AIDS drugs are now patented in India and so cannot be produced by the generic manufacturers, so they will remain out of reach. A big problem, indeed.

And recently TOI reported this story that proves why generic drugs are potent enough to cure diseases at low and affordable costs:

Indian medicine, at 1/100th cost, saves Aussie's life

Less than four months ago, Greg Jeffery was on the verge of getting liver cirrhosis. The 61-year-old Australian, suffering from hepatitis C, desperately needed a drug called Sivoldi to reverse the life-threatening condition.
The problem was, each Sivoldi pill cost over 1,000 Australian dollars and the total treatment regime of 84 tablets would have set him back by around 100,000 dollars.
Jeffery, a historian and author, didn't have that kind of money. Desperate to source the drug at a cheaper rate, he landed in Chennai three months ago. There, he not only got the drug but bought it for less than one-tenth the price in Australia.
"The same treatment with the same drug in India is $900," Jeffery told Australian TV channel, ABC.

" Basically as soon as I got home I started taking it. Within 11 days all my liver functions had returned to normal and within four weeks there was no virus detectable in my blood — I was essentially cured," he told the channel.
Jeffery's story, now all over Australian media, has renewed the debate on whether life-saving drugs should be priced so high.
" If you haven't got the money, for a lot of people it's a death sentence — you die," Jeffery told ABC. " I was right on the edge of cirrhosis of the liver, once you get cirrhosis you then open up to tumours and cancer."
Jeffery is now helping other Australians in a similar situation to source the drug from India.
" I get about 40 to 50 emails every day, seven days a week and they are from people who have hep C, whose mother or father has hep C, wife or husband has hep C," he told the channel.

The story is also a vindication of sorts for India's patent regime that is often criticized in the West for not honouring intellectual property rights in medicine.

Need we say more?