(S)-Flurbiprofen
[CAS# 51543-39-6]

Identification

• Classification: API >> Antipyretic analgesics >> Non-steroidal anti-inflammatory drugs
• Name: (S)-Flurbiprofen
• Synonyms: (2S)-2-(3-fluoro-4-phenylphenyl)propanoic acid
• Molecular Formula: C₁₅H₁₃FO₂
• Molecular Weight: 244.26
• CAS Registry Number: 51543-39-6
• EC Number: 257-263-1
• SMILES: C[C@@H](C1=CC(=C(C=C1)C2=CC=CC=C2)F)C(=O)O

Properties

• Solubility: 17.7 mg/L (25 ºC water)
• Density: 1.2±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.568, Calc.^*
• Melting point: 133.91 ºC
• Boiling Point: 380.71 ºC, 376.2±30.0 ºC (760 mmHg), Calc.^*
• Flash Point: 181.3±24.6 ºC, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS06 Danger
• Hazard Statements: H301
• Precautionary Statements: P264-P270-P301+P310+P330-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301

Discovory and Applicatios

(S)-Flurbiprofen is a chiral derivative of flurbiprofen, a nonsteroidal anti-inflammatory drug (NSAID) that is primarily used for its analgesic, anti-inflammatory, and antipyretic properties. The compound is a part of the propionic acid class of NSAIDs and is known for its ability to reduce pain, inflammation, and fever. (S)-Flurbiprofen specifically refers to the enantiomer of flurbiprofen that has been found to exhibit superior pharmacological properties compared to its (R)-counterpart.

The discovery of (S)-flurbiprofen emerged from the need for more effective and selective NSAIDs. Flurbiprofen itself was developed in the 1970s, with the goal of providing an effective treatment for pain and inflammation while minimizing gastrointestinal side effects. The (S)-enantiomer of flurbiprofen was synthesized to exploit its enhanced potency and improved safety profile. The importance of chirality in drug design was becoming more apparent, and it was found that the (S)-isomer of flurbiprofen was more effective in inhibiting the cyclooxygenase (COX) enzyme, which is responsible for the production of prostaglandins—lipid compounds involved in inflammation and pain.

(S)-Flurbiprofen works by selectively inhibiting the COX-2 enzyme, which is the isoform primarily involved in inflammation. By blocking this enzyme, (S)-flurbiprofen reduces the synthesis of prostaglandins, leading to decreased pain and swelling. Unlike older NSAIDs that inhibit both COX-1 and COX-2 enzymes, which can lead to gastrointestinal issues, (S)-flurbiprofen tends to have a lower incidence of such side effects, making it a more favorable option for long-term use.

(S)-Flurbiprofen is applied in the treatment of a variety of inflammatory conditions, including osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. It is commonly used for pain relief following surgery or injury, especially in cases where inflammation is a significant contributor to discomfort. Due to its effectiveness in treating pain and inflammation, (S)-flurbiprofen is frequently prescribed for managing both acute and chronic pain conditions, including musculoskeletal pain, dental pain, and postoperative pain.

Additionally, (S)-flurbiprofen has been explored for its potential use in treating fever, although this application is less common compared to its use for pain and inflammation. In clinical studies, (S)-flurbiprofen has demonstrated superior efficacy compared to the racemic mixture of flurbiprofen, particularly in the context of anti-inflammatory and analgesic effects. Its enhanced selectivity for COX-2 makes it an important option in the management of conditions where inflammation plays a significant role.

One of the key advantages of (S)-flurbiprofen is its improved safety profile. By reducing COX-2 activity without significantly affecting COX-1, which is involved in maintaining the integrity of the gastrointestinal lining, (S)-flurbiprofen reduces the risk of gastrointestinal irritation, ulcers, and bleeding that are commonly associated with older NSAIDs. This makes (S)-flurbiprofen a preferred choice for patients who need long-term NSAID therapy.

(S)-Flurbiprofen is available in various forms, including oral tablets and topical formulations. It is typically well tolerated, but like other NSAIDs, it can cause side effects such as dizziness, headache, and gastrointestinal discomfort. More serious side effects, such as renal impairment and cardiovascular risks, can occur with prolonged use, especially in patients with pre-existing conditions like hypertension or heart disease.

In conclusion, (S)-flurbiprofen represents a significant advancement in the development of NSAIDs, offering enhanced efficacy and safety compared to its racemic counterpart. Its selective inhibition of COX-2 makes it an effective agent for managing pain and inflammation with fewer gastrointestinal side effects. (S)-Flurbiprofen continues to be a valuable tool in the treatment of various inflammatory conditions, providing both clinicians and patients with a reliable and safer option for pain relief.