Minocycline hydrochloride
[CAS# 13614-98-7]

Identification

• Classification: API >> Antibiotics >> Tetracycline
• Name: Minocycline hydrochloride
• Synonyms: [4S-(4alpha,4aalpha,5aalpha,12aalpha)]-4,7-Bis(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxonaphthacene-2-carboxamide monohydrochloride
• Molecular Formula: C₂₃H₂₇N₃O₇.HCl
• Molecular Weight: 493.94
• CAS Registry Number: 13614-98-7
• EC Number: 237-099-7
• SMILES: CN(C)[C@H]1[C@@H]2C[C@@H]3CC4=C(C=CC(=C4C(=C3C(=O)[C@@]2(C(=C(C1=O)C(=O)N)O)O)O)O)N(C)C.Cl

Properties

• Solubility: 100 mM (DMSO), 25 mM (water) (Expl.)

Safety Data

• Hazard Symbols: GHS07;GHS08 Warning
• Risk Statements: H315-H319-H335-H351-H361
• Safety Statements: P261-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Reproductive toxicity	Lact.	-	H362
Reproductive toxicity	Repr.	2	H361
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Skin sensitization	Skin Sens.	1	H317
Specific target organ toxicity - single exposure	STOT SE	3	H336
Reproductive toxicity	Repr.	1B	H360
Reproductive toxicity	Repr.	1A	H360
Respiratory sensitization	Resp. Sens.	1	H334

Discovery and Applications

Minocycline hydrochloride is a broad-spectrum antibiotic belonging to the tetracycline class of drugs. It is derived from oxytetracycline and is characterized by its extended antimicrobial activity against both Gram-positive and Gram-negative bacteria. Minocycline was first introduced in the 1970s as an effective treatment for a variety of bacterial infections, including those caused by resistant organisms. Its discovery and development were part of ongoing efforts to combat bacterial resistance and improve upon the limitations of earlier tetracyclines, such as tetracycline itself, by enhancing its pharmacokinetics and reducing side effects.

Minocycline works by inhibiting bacterial protein synthesis, which it achieves through binding to the 30S ribosomal subunit, preventing the attachment of aminoacyl-tRNA to the ribosome. This mechanism of action effectively disrupts bacterial growth and replication, making it a valuable tool in treating infections caused by a wide array of pathogens. One of the key features of minocycline is its ability to penetrate tissues and the central nervous system, which makes it particularly useful in treating infections of the brain, such as meningitis.

The primary clinical use of minocycline hydrochloride is in the treatment of various bacterial infections, including respiratory tract infections, urinary tract infections, and skin infections. It has been particularly successful in treating acne vulgaris, often being prescribed as a second-line agent for moderate to severe cases due to its anti-inflammatory properties in addition to its antimicrobial action. Minocycline’s effectiveness against Mycobacterium leprae, the causative agent of leprosy, has also been well-documented, making it an essential component in the multidrug therapy for leprosy.

Beyond its use as an antibiotic, minocycline has been studied for its potential neuroprotective effects. Research has shown that it may have applications in treating neurological disorders, such as Parkinson's disease, Alzheimer's disease, and multiple sclerosis, owing to its anti-inflammatory and antioxidant properties. In addition, minocycline is being investigated for its role in modulating the immune response and reducing inflammation in conditions like rheumatoid arthritis and Crohn's disease.

Despite its broad range of applications, the use of minocycline hydrochloride is associated with several side effects. Common adverse reactions include gastrointestinal disturbances, dizziness, and skin discoloration. Serious side effects, such as liver toxicity and vestibular side effects, are less common but may occur, particularly with prolonged use. Therefore, the use of minocycline must be carefully monitored, especially in patients with pre-existing conditions.

In conclusion, minocycline hydrochloride remains a critical agent in the treatment of various bacterial infections and inflammatory conditions. Its discovery marked an important advancement in the field of antibiotics, and ongoing research continues to uncover its potential in managing neurological and autoimmune diseases.

References

1994. Mycobacterium marinum skin infections. Report of 31 cases and review of the literature. Archives of Internal Medicine, 154(12).
DOI: 10.1001/archinte.154.12.1359

2024. Nanoparticles to Abate Antibiotic Resistance During the Management of Dental Diseases. Nanotechnology Based Strategies for Combating Antimicrobial Resistance.
DOI: 10.1007/978-981-97-2023-1_17

1994. Locally Delivered Minocycline and Guided Tissue Regeneration to Treat Post-Juvenile Periodontitis. A Case Report. Journal of Periodontology, 65(9).
DOI: 10.1902/jop.1994.65.9.835