Notes On Gaseous State This page provides you all details about the gaseous state of BSc standard. Concerned problems will be solved at the end of each concept. Continue till the end to find the easiest explanation of every concept you need in this regard . Postulates of Kinetic Theory of Gases: 1. All gas consist of a very large number of minute particles, called molecules. 2. The gas molecules are extremely small in size and are separated by large distance. The actual volume of the gas molecules is thus negligible as compared to the total volume occupied by the gas. 3. The pressure exerted by the gas is due to the bombardment of the molecules on the walls of the vessel. 4. The gas molecules collide with one another and also with the walls of the vessels. These collisions are perfectly elastic and there is no loss of energy during these collisions. 5. The distance between the gas molecules are very large. Thus, there is no effective force of attraction or r
Evolution and impact of Paracetamol from Its Discovery to Modern-Day Applications
Introduction:
In the realm of modern medicine, few substances have
revolutionized pain relief as significantly as paracetamol. Also known as APAP
(N-acetyl-para-aminophenol), acetaminophen (shortened form of APAP)
or para-hydroxyacetanilide, paracetamol is a widely used
analgesic (relieves pain) and antipyretic (balances elevated body temperature)
that has become a household name in treating common ailments. Its history is
intertwined with scientific advancements, medical breakthroughs, and the
persistent pursuit of finding effective pain management solutions. This post
aims to delve into the captivating history of paracetamol, uncovering its
origins, development, and its enduring impact on society.
Discovery and Early Development:
The roots of paracetamol (CAS or Chemical Abstract Service
Number: 103-90-2, Chemspider ID: 1906) can be traced back to the late 19th
century. In 1877, a American / German chemist named Harmon Northrop Morse first
synthesized a compound called p-aminophenol. However, it was not until 1887 that
German scientist, Josef von Mering, rediscovered its analgesic properties.
Initially, paracetamol's potential went largely unnoticed as it took several
decades for researchers to fully appreciate its therapeutic benefits.
Recognition and Medical Application: Paracetamol's recognition as a valuable pharmaceutical
compound gained traction in the mid-20th century. In 1955, a team of
researchers led by Morris K. Kline and Leon Greenberg at the pharmaceutical
company McNeil Laboratories discovered the compound's remarkable analgesic
effects. Shortly after, McNeil launched the first paracetamol-based product
under the brand name "Tylenol" in the United States in 1955. Other
brand name includes Panadol, Calpol etc.
How does paracetamol act in body: In simple terms, paracetamol works by blocking or reducing
certain chemicals in the body that cause pain and fever. When you're in pain or
have a fever, your body releases substances called prostaglandins, which are
responsible for transmitting pain signals and causing inflammation.
Paracetamol targets these prostaglandins and inhibits their
production. By doing so, it helps to alleviate pain and reduce fever. It acts
mainly on the central nervous system, which includes the brain and spinal cord,
where it blocks the transmission of pain signals.
Unlike some other pain relievers, paracetamol doesn't have
strong anti-inflammatory effects, meaning it doesn't reduce swelling or
inflammation as effectively. Its primary focus is on relieving pain and
reducing fever.
The fact is, pure paracetamol is not a potent application
but in combination such as acceclophenac, Ibuprofen, aspirin, caffeine it works
very well in mild to moderate pain relief.
Simplified overview of the main steps involved in its
synthesis:
Starting Compound: The
synthesis of paracetamol typically begins with a starting compound called
phenol, which is derived from petroleum or coal tar.
Nitration: The
phenol undergoes nitration, where it reacts with nitric acid (HNO3) and
sulfuric acid (H2SO4). This reaction introduces a nitro group (-NO2) onto the
phenol molecule, resulting in the formation of 4-nitrophenol.
Reduction: The
4-nitrophenol is then reduced to 4-aminophenol. This reduction is typically
achieved using a reducing agent such as sodium borohydride (NaBH4) or iron in
the presence of hydrochloric acid (HCl).
Acetylation: The
4-aminophenol is acetylated by reacting it with acetic anhydride (C4H6O3) or
acetyl chloride (CH3COCl) in the presence of a catalyst, usually pyridine or
sodium acetate. This reaction introduces an acetyl group (-COCH3) onto the
amino group of the 4-aminophenol, resulting in the formation of paracetamol.
Purification: The
crude paracetamol product is purified through various techniques such as
crystallization, filtration, and recrystallization. These processes help remove
impurities and obtain a pure form of paracetamol.
Safety and Regulatory Challenges: As paracetamol gained popularity, concerns regarding
its safety emerged. In the 1960s, reports of paracetamol-induced liver toxicity
began to surface, leading to a temporary decline in its usage. However, further
research and subsequent regulatory measures, including dose adjustments and
labeling requirements, helped mitigate these risks. Today, paracetamol remains
a safe and widely available over-the-counter medication when used responsibly
and according to the recommended dosage.
Expanding Applications and Clinical Advancements: Over the years, paracetamol's applications expanded beyond
pain relief. It gained recognition as an antipyretic, making it a go-to
medication for reducing fever in both adults and children. Its efficacy,
combined with its favorable safety profile, established paracetamol as a staple
in households and healthcare settings worldwide. Ongoing research continues to
explore its potential therapeutic uses, such as in the management of
osteoarthritis and postoperative pain.
Societal Impact and Global Accessibility: Paracetamol's impact on society extends far beyond its
medicinal properties. Its accessibility and affordability have made it a vital
component of healthcare systems globally, particularly in low-resource
settings. The World Health Organization (WHO) includes paracetamol on its List
of Essential Medicines, emphasizing its importance in public health and the need
for its availability worldwide.
Conclusion: The
journey of paracetamol, from its modest beginnings to its pervasive presence in
modern medicine, showcases the profound impact of scientific discovery and
relentless pursuit of effective pain relief. As an analgesic, antipyretic, and
widely used medication, paracetamol has transformed the lives of countless
individuals, providing relief from pain and fever while becoming an integral
part of healthcare systems worldwide. Its history serves as a reminder of the power
of innovation and highlights the potential of pharmaceutical advancements to
enhance human well-being.