Definitions of a drug Different Types of Drugs

Definitions of a drug. What is a drug? Any chemical compound that may be used on or administered to humans to help diagnose, treat, cure, mitigate, or prevent disease or other abnormal conditions

Regulatory definition of drug
An article or substance that is recognized by the US Pharmacopoeia, National Formulary, or official Homeopathic Pharmacopoeia, or supplement to any of the above intended for use in the diagnosis, cure, mitigation, treatment or prevention of disease in man or animals intended to affect the structure or any function of the body of man or animals Substance abuse Any medication

Radioactive Drug: Any substance defined as a drug in 201(b)(1) of the Federal Food, Drug and Cosmetic Act that exhibits spontaneous disintegration of unstable nuclei with the emission of nuclear particles or photons [21 CFR 310.3(n)]. Included are any nonradioactive reagent kit or nuclide generator that is intended to be used in the preparation of a radioactive drug and “radioactive biological products,” as defined in 21 CFR 600.3(ee). Drugs such as carbon-containing compounds or potassium-containing salts containing trace quantities of naturally occurring radionuclides are not considered radioactive drugs.

Radiopharmaceuticals: Radioactive drugs that are labeled or tagged with a radioisotope. These materials are largely physiological or pharmacological in action, and, in many cases, function much like materials found in the body. The principal risk associated with these materials is the consequent radiation exposure to the body or to specific organ systems when they are introduced into the body.
Investigational New Drug or Device: A drug or device permitted by FDA to be tested in humans, but not yet determined to be safe and effective for a particular use in the general population, and not yet licensed for marketing.

Drug product:
Drug product means a finished dosage form, for example, tablet, capsule, or solution, that contains a drug substance, generally, but not necessarily, in association with one or more other ingredients (21 CFR 314.3 (b)).

Drug substance:
Drug substance means an active ingredient that is intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure or any function of the human body, but does not include intermediates used in the synthesis of such ingredient (21 CFR 314.3 (b)).

What is a Prodrug :
A prodrug is as such a pharmacologically inactive drug but when administered it get converted in vivo in to a pharmacologically active molecule. Prodrugs are intentionally designed to overcome degradation in gut and first pass metabolism , and make a drug available for action for longer time and also to increase its bioavailability, some naturally occurring drugs too are prodrugs which get converted in to pharmacologically active form.
Example of prodrugs :
Lisdexamfetamine it is a prodrug L-Lysin is coupled with dextroamphetamine molecule form Lisdexamfetamine it get metabolized in to an active form dextroamphetamine .

What is an orphan drug:
An orphan drugs is a drugs which are developed specifically for treating a rare diseases , a rare medical condition or disease symptoms such diseases are also termed as orphan disease.
Usually a disease that affects about one individual out 200000 peoples.

Development of orphan drugs are always encouraged as there is very less market requirement for such drugs and developmental costs too are high , hence some relaxation in fees and clinical trials is given by governments of USA and along with exclusive marketing rights to pharmaceutical companies taking initiatives for developing orphan drugs, many European countries too encourage pharmaceutical companies for developing orphan drugs by giving similar facilities to pharmaceutical companies.

What is a Investigational New Drug (IND):
A drug is said to be Investigational New Drug when a pharmaceutical manufacturer want to develop it for treating a disease or an indication , to undertake research and development such drug , the drug should be get approval from US FDA , for which pharmaceutical manufacturer is required to submit Investigational Drug Application ( IND ), after getting an approval for such drug it can be then transported and used in a clinical trials normally it is tested first in phase 1of a clinical trial.

What is Placebo ?
Placebo is a substance which do not contain any active ingredient, or any drug, rather it is designed to just look alike the actual drug dosage form, it is formulated by using sugar, or other inert pharmaceutical additives, it is widely used in research as control to find out the effect of an actual drug with respect to the treatment with placebo, some times placebo produce equal effect when used to treat a disease or a condition, which is merely because of the psychological effects and feeling of being treated with drug and doctor. Similarly a treatment and medical procedures are designed just to mimic the actual therapy are also called as placebo, some patients are given treatments which are not actually real ones but they just mimic the actual treatments are called as simulated medical intervention.

Here is an example of a Investigational New drug being approved for treating a rare disease condition.
Process of approval of a drug for marking in USA:
Drugs which has some hope for beneficial effects in treating any disease, conditions or symptoms are first tested in animals . As animal trials do not necessarily demonstrate complete physiological, pharmacological, or toxicological effects of a new drug under study.
Drugs are approved for marketing only after evaluation of their effectiveness , efficacy and safety in human beings. These evaluations are usually done through clinical trials, and after thorough evaluation of out come of clinical trial, if it is found that a drug is effective and safe and properly labeled [21 CFR 312 and 21 CFR 314] for use in conditions indicated , then only a drug is approved for marketing in USA. The Food and Drug Administration (FDA) is responsible for monitoring the testing of new drugs in humans, and all clinical trial are regulated by US FDA.

What is a Brand Name Drug :
When drug molecule is completely researched and developed in to a drug product for a particular disease or its symptom or for a  indication or when he applies new technology to an existing molecule so as to enhance the efficacy safety or new route of administration , such drug products then are investigated for their safety and efficacy , and after approval clinical studies , a manufacturer generally applies for a patent for the drugs developed by them so as to enjoy the monopoly of getting his product’s sale for which he invented the drug for a particular disease.

What is a Generic Drug:
Refer this link for generic drug we have provided all details about generic drug.

Why there are some drugs said to be unapproved and are there available in market.

Many of these unapproved drugs are older products introduced well before formation of FDA  in 1938 these drug products were approved on the basis of 1906 Pure Food and Drug Act, that required a drug for getting an approval only to comply with some standards of strength and purity and not for safety.

Also earlier in 1960’s drugs were given approval based on only aspects of safety and efficacy , but safety study like clinical trials for safety were not under control by FDA, until the heroic rejection of drug containing thalidomide in 1960 by Madam Dr Frances Oldham Kelsey an US FDA employee then. Her decision actually saved millions of American children’s from disabilities, which forced US legislation to pass an act to provide an additional authority to FDA to make it mandatory for a drug to be proved that it is a safe by conducting clinical trials which are completely assessed by US FDA to get an approval for marketing a drug in USA.

What is a Grand Fathered Drug , Which are the Grand Father Drug Clauses:

Under the 1938 grandfather clause a drug product that was on the market prior to passage of the 1938 Act and which contained in its labeling the same representations concerning the conditions of use as it did prior to passage of that Act was not considered a new drug and therefore was exempt from the requirement of having an approved new drug application.

Under the 1962 grandfather clause, the Act exempts a drug from the effectiveness requirements if its composition and labeling has not changed since 1962 and if, on the day before the 1962 Amendments became effective, it was (a) used or sold commercially in the United States, (b) not a new drug as defined by the Act at that time, and (c) not covered by an effective application.

The two grandfather clauses in the Act have been construed very narrowly. There are very few drugs on the market that are actually entitled to grandfather status because the drugs currently on the market likely differ from the previous versions in some respect, such as formulation, dosage or strength, dosage form, route of administration, indications, or intended patient population. If a firm claims that its product is grandfathered, it is that firms burden to prove that assertion.

There are three types of unapproved drugs
A.DESI Drugs
DESI means Drug Efficacy Study Implementation
Refers to a drug that is a subject of 1938-1962 NDAs (safety only) and drug which is identical, related, and similar to such drugs.
DESI drugs are not “grandfathered” or generally recognized as safe and effective (GRAS/E)

B.Prescription “Wrap-Up”
Refers to drugs that are on the market based on a claim of being a pre-’38 or pre-’62 product or identical, related, or similar to such a product

C.Post ’62 Drugs
Drugs initially marketed after 1962