Examining Anti Inflammatory Pain Relief Drugs Biology Essay

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Pulverized PharmXS (0.7003) was dissolved in 5mL of dichloromethane in a 125 mL Erlenmeyer flask. Vacuum filtration was performed to give white power like sucrose (0.0977g). The dichloromethane filtrate was extracted twice with two separate 5 mL portions of 10% sodium carbonate solution, and about 8 drops of 6M hydrochloric chloride were added to the combined aqueous extracts to bring to PH to 2. The aqueous extracts were then vacuum filtered to give aspirin (0.0431g). About a gram of granular calcium chloride was added to the dichloromethane solution to remove the water, and the solid calcium chloride was removed by gravity filtration. The dichloromethane solution was then evaporated by a flash evaporator to give the unknown compound (0.2216g). Melting point of the retrieved aspirin and the unknown product was determined separately. The aspirin and the unknown product were dissolved in methanol solution for TLC spotting. On a separate plate, the following sample solution, acetanilide, phenacetin, acetaminophen, and aspirin, were spotted. The plates were developed using 100% acetonitrile as the developing solvent and were examined under the UV lamp.


Non-opioid analgesics such as acetaminophen, aspirin and the non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used of all therapeutic agents. Their chief use is in the treatment of mild to moderate pain, but the also have anti-pyretic and anti-inflammatory effects. They are therapeutic agents that can be used in the management of pain, pyrexia and inflammatory conditions.

Acetanilide, phenacetin, and acetaminophen are mild analgesics (pain relieving) and antipyretics (fever reducing) and are important, along with aspirin, in many nonprescription drugs. Medications generally considered for fever reduction include salicylates (aspirin), aminophenols (acetaminophen, phenacetin, and acetanilide), indomethacin, and phenyl pyrazoles (dipyrone). Phenacetin has all the general properties of acetaminophen and it has only moderate antipyretic and analgesic activity. The risks of phenacetin outweigh its benefits for treatment of fever because it can induce methemoglobinemia, hemolysis, and possibly nephritis. Acetanilid has similar adverse effects and thus is not routinely used for antipyresis or analgesia. Indomethacin has considerable antipyretic and analgesic activity. However, a relatively high incidence of central nervous system and hematologic side effects limits its routine use. Phenyl pyrazoles such as dipyrone have antipyretic action, but their clinical usage is limited because of their high incidence of aplastic anemia.

Aspirin is an effective treatment for pain associated with headache, musculokeletal disorders and dysmenorrheal. It also has an antipyretic action and some anti-inflammatory effects. Aspirin is an effective analgesic, but acetaminophen is preferred because it has similar efficacy and fewer side effects. Aspirin achieves its analgesic, anti-inflammatory and antipyretic actions by inhibiting the activity of the enzyme cyclooxygenase 2 (COX-2). This enzyme is generated in acutely inflamed tissues and converts a substance known as arachidonic acid to prostaglandins. Prostaglandins are major contributors to the production of pain, inflammation and increased body temperature. Aspirin inhibits the synthesis of prostaglandins and appears to reduce pain, limit inflammation and reset temperature control to normal levels. Aspirin also inhibits the cyclooxygenase enzyme COX-1. This can make the stomach more susceptible to injury in some patients.

Acetaminophen: The mechanism of action of acetaminophen, which has both analgesic and anti-pyretic properties, is poorly understood. It is thought the antipyretic action is caused by inhibition of prostaglandin synthesis in the brain and the analgesic effect is the result of the selective inhibition of the COX-3 enzyme in the brain and spinal cord. It has no significant effect on COX-1 and COX-2 enzymes, which explains its lack of anti-inflammatory action and lack of unwanted gastrointestinal side effects. It has a major advantage over aspirin and the non-selective NSAIDs in that it does not cause gastric irritation. As a result, it is preferred, and generally considered a safer alternative, to these drugs, particularly in older adults.

Treatment with the aspirin-acetominophen combination resulted in more sustained reduction in fever.When aspirin and acetaminophen have been combined, the combination has shown a statistically significant advantage at the times evaluated when compared to aspirin alone.

Nonsteroidal anti-inflammatory drugs (NSAIDs) including aspirin are the most widely used drugs in the world. Examples include ibuprofen, diclofenac, naproxen and fenoprofen. Non-steroidal anti-inflammatory drugs NSAIDs form a large group of drugs used to treat pain and inflammation. NSAIDs are used to treat tissue disorders such as muscle and ligament strains, and also dysmenorrhea, post-operative pain and migraine. NSAIDs are similar to aspirin in that they have same therapeutic effects and are used as potent drugs in the treatment of inflammation, high fever and moderate pan. The mechanism of action of these drugs is similar to the mechanism of Aspirin, which is based on the inhibition of cyclooxygenase enzyme (COX) pathway. It is known that at least two isoenzymes exist: COX-1, which protects the stomach lining and intestine, and COX-2, that is involved in the inflammation process. They act by inhibiting the COX-2 enzyme, and this action suppresses the formation of the prostaglandins produced in response to tissues damage, which results in reduced pain and inflammation.

Objective: the objective of this experiment is to determine if the pulverized sample Pharm XS that were given are genuine products or counterfeits by separate the drug into its components and then to confirm the identity of each component. PharmXS is a white tablet that contains three component, two analgesic-antipyretic compounds, acetanilide and phenacetin, and a binding agent. The counterfeits have antipyretic and analgesic properties as the genuine products do, but they have some unusual side effects not associated with aspirin or acetaminophen. It has been confirmed that either of the acetanilide or phenacetin was substituted for acetaminophen in the counterfeited samples. Acetanilide and phenacetin are analgesic-antipyretics, but they are no approved drugs because of the unfavorable side effects they carry.


Table1. Table of retrieved compound, their amount of composition, percentage composition, Rf value and melting point.

Compound Yield (%) Yield (g) Rf Melting point ()

Aspirin 0.0431 0.78 129-132

Unknown 0.2216 0.76 99-102

Sucrose 0.0977 178-183

Table 2 Table of literature melting points, physical properties and toxicity reports of compounds

Compound Melting point Physical properties Toxicity reports

Sucrose 185-186

Aspirin 135

Acetanilide 113-115

Phenacetin 134-135

acetaminophen 169-170.5

Table 3. Rf value of possible unknown compounds.

Compound Rf

Aspirin 0.85

Acetanilide 0.71

Phenacetin 0.71

Acetaminophen 0.56

Analysis of PharmXS indicated it to consist of sucrose (% by weight), aspirin (% by weight) and the unknown compound (% by weight).


How you used collected data to id each component

(Rf, melting point, and NMR)

Yield, errors and uncertainties found

state findings again finally with numbers to show objectives were met

references 2

relative percentage, address inconsistencies, it the sample was a counterfeit

comment on uncertainty

The unknown compound was identified to be acetanilide. The Rf value for the unknown is 0.76, and the Rf values for acetanilide and phenacetin are both 0.71. The melting point of the unknown is 129-132°C, which is closest to the melting point of acetanilide (113-115°C) among acetanilide, phenacetin (134-145°C) and acetaminophen (169-170.5 °C).

How you used collected data to id each component

(Rf, melting point, and NMR)

Yield, errors and uncertainties found

state findings again finally with numbers to show objectives were met