The process of drugs in pharmaceuticals is actually a very long one. There are several different stages that a company undertakes in order to get their drug to the doctors, pharmacists and patients. We will look at this process over the next few minutes. Introduction:
As a Chemistry major I’m passionate to study on drugs and would like to involve in pharmaceuticals. I’m also inspired from my family where my brothers-in-law are pharmacist and besides I love chemistry since my high school. People all over the world are taking drugs for certain to millions of reasons which lead number of drugs to billions. Drugs are served as pills or syrup as well as injectors.
Most of the people in the world are taking drugs as a pill but they never feel it takes 15 to 20 years to reach their hands. In other words, it takes twenty years a drug from discoveries to come into the market. The answer for this many years to be safety for the people and during drugs are tested and designed and also modified for less harmful and more effective.
1. Main Point:
Drug Discovery is a very few first steps in its journey to the market. A. Drug discovery is a process in medicine and pharmacology where a drug is discovered and designed. In the past drug discovery was very different to the current form, previously active ingredients were used to tackle illnesses.
Nowadays more detailed research on diseases has been pursued, details such as what the genes are coding or what protein is involved, therefore are allowing the designing of drugs to target specific sites to act on the disease. Most of the drugs came from nature even now a day, lead compounds are found in nature, which later are sent for development.
Professor Silverman mentions in his book, ‘The Organic Chemistry of Drug Design and Drug Action’ that, ‘Greater than 60% of the anticancer and anti-effective agents that are on the market or in clinical trials are of natural product origin or derived from natural products.’
I. As most of the compounds are found in nature, scientists believe that most of the early drugs were discovered accidentally, which means the initial compound was prescribed for one purpose but in clinical test the drug were sometimes found for another treatment. As Professor Subash Jonnalagadda from Rowan University said in his interview, ‘
Lots of drugs are accidental such as Viagra, which was discovered in early 90’s to help man suffering chest pains from heart diseases but came up with an odd side effect-erections.’ His examples included the drug minoxidil, which was approved for high blood pressure but later it was also prescribed for hair restorer.
B. Now a day scientists know the specific target of the disease therefore they mark possible compounds including the natural one to get the correct one, and thus drug discovery is a very time consuming and expensive process. Estimate of the average time required to bring a drug to the market range from 12-15 years at an average. Professor Richard B.
Silverman reports in his book that, ‘the industry estimates that the average cost of developing a successful drug is about $ 800 million.’ Therefore it makes to the fact that, pharmaceuticals spend more money on lost opportunity and uncovered financial losses of the company rather they do on research and development.
The New York Times reported in 2000, ‘Pharmaceutical companies spend more than $20 billion annually on research and development.’ Besides the companies spend more on drug development than on research. In total, the cost gives the idea that, new drugs in the market are too costly because not of its manufacture but the profit are needed to pay for all the drugs that fail to make it to market after large sum of research funds have already been expanded.
2. Main Point:
Drug design is the pre-stage of clinical trials whereas trial includes the verification and development of drugs. A. When such a molecule is being identified as drug, based on the detailed information of the disease it is designed further. Once detailed information of the disease has been recorded and the target identified, there are couple more stages for target identification.
If the pharmaceutical is working on an existing disease then they will target either the same target as current drugs and if the disease target is new then they work on the pathophysiology of the disease, which means a new protein or enzyme receptor. Drug usually binds with enzyme inside the body and accomplish their activities based on the structure of it and how it compete with ligand that produces inside the body.
Professor Subash explained in his interview that, there are drugs classified agonists, antagonists, super-agonists, inverse-agonists based on the competition and binding ability to the receptor and carry out the reactions. He added, ‘cancer occurs for uncontrolled cell growth and the drug are designed to inhibit DNA synthesis. MTX or Methotrexate is widely known for the treatment of leukemia where it plays role to bind with receptors as agonist and blocks the synthesis.’
I. Usually the structure of the molecule is quite complex but, only a small portion of it binds with receptor which is called pharmacophore that increase efficacy, potency and determine the long-term effect of that drug. The small portion of that molecule either block to further reaction or compete with other endogenous ligand in the body to remove the disease.
The other portion determines some physical characteristics according to the receptor and easily remove themselves after the function meets successfully. Bioavailability of drugs is also important factor which includes solubility, the ability to cross biological barrier by either active or passive diffusion processes, plasma protein binding, susceptibility to enzymatic modification and excretion properties.
II. After years spend on molecular modification for the systematic improvement, pharmaceuticals move on to the dose stage. It really means to determine maximum safety of the drug, which is called ‘Therapeutic Index or Ratio.’ It is actually a measure of the safety of a drug as determined from the concentration of a drug that gives undesirable effects to that which gives desirable effects.
It is assumed or calculated for 50% of dose response in animals or humans compare to its concentration. Professor Silverman mentions, ‘Often it is taken as the dose –limiting toxicity versus the desirable pharmacological effect in an animal model (preferably human.).’ He also added, the ratio could be of the LD50 (the lethal dose for 50% of the test animals) to the therapeutic ED50 (the effective dose that produces the maximum therapeutic effect in 50% of the test animals.
It indicates that, larger the Therapeutic Index means the greater the margin of safety of the compound. Professor Subash ended the answer in his interview, ‘you would like to have to administer gram quantities of the drug before any undesirable effect are observed, but administer only milligrams of the drug to attain the desirable effect.’ B. In a clinical trial (also called an interventional study), participants receive specific interventions according to the research plan or protocol created by the investigators.
The investigators try to determine the safety and efficacy of the drug by measuring certain outcomes in the participants. There are some phases that described in drug development. In primary stage exploratory studies involving very limited human exposure to the drug with no therapeutic or diagnosis goals (e.g. screening studies, microdose studies). In phase I, Studies that are conducted with healthy volunteers and that emphasize safety.
The goal is to find out what the drug’s most frequent and serious adverse events are and, often how the drug is metabolized and excreted. According to Professor Silverman the phase takes generally a year and half which includes the safety, tolerability, pharmacokinetics properties, and pharmacological effect in 20-100 volunteers. In phase II, Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition).
For example, participants receiving the drug may be compared with similar participants receiving a different treatment, usually an inactive substance (called a placebo) or a different drug. Safety continues to be evaluated, and short-term adverse events are studied. Phase III is longer than other two. Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.
Professor Silverman mentions, it takes several months to several years with thousands patients to establish the efficacy of the drug and monitors adverse reaction from long-term use. Phase IV studies occurring after FDA has approved a drug for marketing. These including postmarket requirement and commitment studies that are required of or agreed to by the sponsor. These studies gather additional information about a drug’s safety, efficacy, or optimal use.
I. Clinical trials are the most costly part of bringing a drug to the market.
This is because for clinical purpose thousands of compounds are selected but at the end only comes up with one compound but the company has to pay for others compound research.
The New York Times reports, ‘For every 5,000 to 10,000 compounds the industry screens as potential new medicines, 250 make it to the stage of testing in animals. Of these five enter testing in people, in clinical trials.’ Drug candidates which are also known as NCE (new chemical entities) that fail in this process result in huge, uncovered financial losses for the company. This is why, drugs prices are so high, as The New York Times reports, the costliest clinical trial is the phase III, which can cost $10,000-$20,000 a patient.
3. Main Point:
Drug patent is the sequence of making drugs and till it sales to the market for certain under protection. A. A patent is simply a contract between the owner and the government for a limited monopoly in exchange for full disclosure of an invention. It acts as a shield, permitting the patent owner to prevent others from making, selling or using it within that country.
The contract of ‘Letter Patent’ (as formerly named) only lasts in the U.S. for 20years from date of filing the application. Due to the length of time to obtain a patent, pharmas also have to go through the regulatory process. According to The New York Times, ‘Between 1992 and 1997, the industry paid the agency $327 million to hire 600 new reviewers.’ In this process, the drug approval time has dropped to 12months, from about 30months or more. As result, the price of new drugs in the market is so high until the patent expires and generic drugs come to the market.
I. Generic Drugs are chemically identical copies of drugs that may be marketed when patents or other exclusive marketing rights on brand name drugs expire. Once the patent expires generic copies of such drugs may be sold with the FDA’s permission. Therefore, others companies spend less efforts and time and make profits because of the availability.
As author J P Bae mentions in his article, ‘Drug Patent expirations and the speed of generic entry’ that, ‘the innovative pharmaceutical industry spends more than 16 percent of total revenue on research and development (Pharmaceutical Manufacturing Association 1993). In comparison, generic companies need only to replicating already invented chemical molecules for manufacturing.’ In fact, generic drugs expands their market so fast because of their low and reasonable price and its availability.
Companies are in competition to produce generic drugs as Professor Subash mentioned in his interview that, ‘Tylenol as well as Ibuprofen (Motrin) is generic of Acetaminophen which was discovered in 1950, which is popular now a day for pain with less price.’ An estimated 44 percent of all prescriptions in the United States are filled with generic drugs, he added.
II. Even though patent is required to protect such kind of discovery but many scientists believe that, the innovations should not be patented at all. The companies now a day are fighting for patent extensions to generate profit for research, but it spur innovation too few of them.
Selman Waksman, professor from Rutgers University invented a breakthrough antibiotic, streptomycin in the 1940’s and patented the drug. But, he gave away the rights as e result many companies sold streptomycin keeping prices and profits low, as The New York Times reports. Therefore, it becomes a debate whether a patent should be applied or it just goes away for human kind.
The drug activities include its origin, development, clinical research and patent before it comes to the market. The drug design and its development are most critical steps to declare a drug and patent is all business since it reaches to hands. Now a day, lots of diseases can be treated through drug design because scientists can identify the target and build up molecules those mostly suite.
However, drugs are more complex than it seems like a small pill to people, because it is a piece of bunch of research, lots of investment and efforts. In short, the process in pharmaceuticals gives an idea how people inside it devote themselves to come up with new drugs that save millions lives.