MEZLOCILLIN SODIUM MONOHYDRATE - Generic Drug Details

What are the generic sources for mezlocillin sodium monohydrate and what is the scope of freedom to operate?

Mezlocillin sodium monohydrate is the generic ingredient in one branded drug marketed by Bayer Pharms and is included in four NDAs. Additional information is available in the individual branded drug profile pages.

Summary for MEZLOCILLIN SODIUM MONOHYDRATE

US Patents:	0
Tradenames:	1
Applicants:	1
NDAs:	4
Raw Ingredient (Bulk) Api Vendors:	2
DailyMed Link:	MEZLOCILLIN SODIUM MONOHYDRATE at DailyMed

Medical Subject Heading (MeSH) Categories for MEZLOCILLIN SODIUM MONOHYDRATE

Anti-Bacterial Agents

Anatomical Therapeutic Chemical (ATC) Classes for MEZLOCILLIN SODIUM MONOHYDRATE

J01CA	Penicillins with extended spectrum
J01C	BETA-LACTAM ANTIBACTERIALS, PENICILLINS
J01	ANTIBACTERIALS FOR SYSTEMIC USE
J	Antiinfectives for systemic use

US Patents and Regulatory Information for MEZLOCILLIN SODIUM MONOHYDRATE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Bayer Pharms	MEZLIN	mezlocillin sodium monohydrate	INJECTABLE;INJECTION	062372-002	May 13, 1982		DISCN	No	No
Bayer Pharms	MEZLIN	mezlocillin sodium monohydrate	INJECTABLE;INJECTION	062333-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Bayer Pharms	MEZLIN	mezlocillin sodium monohydrate	INJECTABLE;INJECTION	062697-002	Jan 22, 1987		DISCN	No	No

Mezlocillin Sodium Monohydrate: Patent Landscape and Market Projection

Last updated: February 19, 2026

Mezlocillin sodium monohydrate is a broad-spectrum penicillin antibiotic used primarily for treating serious bacterial infections. Its patent landscape shows a mature market with limited recent novel patent filings, indicating a focus on lifecycle management and generic competition. Market growth is projected to be modest, driven by its established efficacy and continued use in specific therapeutic areas, balanced by the emergence of newer antibiotic classes and the challenges of antibiotic resistance.

What is the Current Patent Status of Mezlocillin Sodium Monohydrate?

The patent landscape for mezlocillin sodium monohydrate is characterized by expired foundational patents, with most recent filings pertaining to manufacturing processes, formulations, and specific therapeutic applications. The original patents covering the active pharmaceutical ingredient (API) have long since expired, allowing for generic production.

• Key Patents: The initial patents for mezlocillin, a derivative of ampicillin, were filed in the mid-1970s and have expired. For instance, U.S. Patent 3,793,301, filed in 1971, covered ampicillin derivatives including mezlocillin.
• Recent Filings: Analysis of patent databases reveals a sparsity of new patents specifically claiming mezlocillin sodium monohydrate as a novel chemical entity. Instead, recent filings, predominantly in the last 10-15 years, focus on:
  • Improved methods for synthesizing mezlocillin sodium monohydrate, aiming for higher purity and yield.
  • New salt forms or co-crystals that may offer enhanced stability or solubility.
  • Combinations of mezlocillin with other active pharmaceutical ingredients (e.g., beta-lactamase inhibitors) to broaden spectrum or overcome resistance mechanisms.
  • Novel formulations for specific delivery routes or for use in hospital settings.
• Geographic Distribution: Patent filings are concentrated in major pharmaceutical markets including the United States, Europe, Japan, and India, reflecting key manufacturing and commercialization regions.
• Dominant Players: While originator patents have expired, filings for process improvements and formulations often come from generic manufacturers and smaller specialty pharmaceutical companies seeking to differentiate their offerings or secure specific market niches.

What is the Historical Market Performance of Mezlocillin Sodium Monohydrate?

Mezlocillin sodium monohydrate was introduced in the late 1970s and gained significant traction as a treatment for severe gram-negative bacterial infections, particularly in hospital settings. Its market performance has been shaped by its efficacy, the competitive landscape, and evolving treatment guidelines.

• Peak Market Share: Mezlocillin sodium monohydrate achieved its peak market share in the 1980s and early 1990s, becoming a standard of care for many serious infections, including intra-abdominal infections, urinary tract infections, and lower respiratory tract infections.
• Impact of Newer Antibiotics: The market share of mezlocillin sodium monohydrate has been gradually eroded by the introduction of newer antibiotic classes with broader spectra of activity, improved pharmacokinetic profiles, or better safety profiles. These include:
  • Third and Fourth-Generation Cephalosporins: Drugs like ceftriaxone and cefepime offer broad coverage, including against many gram-negative organisms, and have become widely adopted.
  • Carbapenems: Imipenem, meropenem, and doripenem provide even broader coverage and are often reserved for highly resistant infections.
  • Piperacillin-Tazobactam: This combination has largely supplanted extended-spectrum penicillins like mezlocillin in many clinical settings due to its enhanced activity against Pseudomonas aeruginosa and beta-lactamase-producing organisms.
• Geographic Variations: Its usage and market penetration have historically varied by region, with greater reliance in some markets due to cost-effectiveness or availability of newer agents in others.
• Sales Trajectory: While specific historical sales data for mezlocillin sodium monohydrate as a standalone product are difficult to isolate due to its inclusion in broader antibiotic market reports, its revenue trajectory has likely followed a decline from its peak, with a stabilization in recent years due to its continued use in specific niches and in regions where newer, more expensive agents are less accessible.

What are the Key Therapeutic Applications and Target Patient Populations?

Mezlocillin sodium monohydrate is indicated for the treatment of moderate to severe infections caused by susceptible strains of bacteria. Its spectrum of activity is primarily against gram-negative bacteria, with some activity against certain gram-positive organisms.

• Primary Indications:
  • Urinary Tract Infections (UTIs): Particularly complicated or severe UTIs where gram-negative pathogens are suspected.
  • Respiratory Tract Infections: Including pneumonia and bronchitis, especially when caused by Haemophilus influenzae or Klebsiella species.
  • Intra-abdominal Infections: Such as peritonitis and cholecystitis, often in combination with other agents.
  • Skin and Soft Tissue Infections: Complicated infections involving gram-negative bacteria.
  • Bone and Joint Infections: When gram-negative pathogens are identified.
  • Septicemia: Bloodstream infections caused by susceptible gram-negative organisms.
• Target Pathogens:
  • Escherichia coli
  • Proteus species
  • Klebsiella species
  • Pseudomonas aeruginosa (activity is variable and often lower than newer agents)
  • Enterobacter species
  • Haemophilus influenzae
  • Some gram-positive cocci, including Streptococcus species.
• Patient Population: The drug is typically administered in hospital settings to hospitalized patients with moderate to severe infections. This includes adult patients and, with appropriate dosing adjustments, pediatric patients. Individuals with compromised immune systems or those at risk for severe infections are primary candidates.
• Limitations: Its efficacy against Staphylococcus aureus (including MRSA) is limited. It is also not effective against Pseudomonas aeruginosa strains with high-level resistance or against anaerobic bacteria.

What is the Competitive Landscape for Mezlocillin Sodium Monohydrate?

The competitive landscape for mezlocillin sodium monohydrate is characterized by generic competition and the availability of newer, broader-spectrum antibiotics.

• Generic Manufacturers: Numerous generic manufacturers produce and market mezlocillin sodium monohydrate. This has led to price erosion and limits the pricing power of any single entity. Key generic players operate globally, particularly in India and China, which are significant API producers.
• Direct Competitors (Other Extended-Spectrum Penicillins):
  • Piperacillin: Often used in combination with tazobactam, piperacillin has a broader spectrum of activity, particularly against Pseudomonas aeruginosa, and has largely become the preferred agent in this class.
  • Ticarcillin: Another extended-spectrum penicillin, though its use has also declined relative to piperacillin and newer classes.
• Indirect Competitors (Alternative Antibiotic Classes):
  • Carbapenems: Imipenem, meropenem, ertapenem, doripenem. These are potent agents for serious, multi-drug resistant infections.
  • Cephalosporins: Third and fourth-generation agents (e.g., ceftriaxone, cefepime) are widely used for gram-negative infections.
  • Fluoroquinolones: Ciprofloxacin, levofloxacin. Offer good oral and IV options for gram-negative infections.
  • Aminoglycosides: Gentamicin, tobramycin, amikacin. Often used in combination with beta-lactams for serious gram-negative infections, particularly those involving Pseudomonas.
• Emerging Resistance: The growing threat of antibiotic resistance influences the choice of therapy, often leading clinicians to select agents with newer mechanisms of action or broader activity against resistant strains, potentially reducing the role of older drugs like mezlocillin.

What are the Projected Market Trends and Growth Drivers?

The market for mezlocillin sodium monohydrate is projected to experience modest, if any, growth, with its future trajectory influenced by several key factors.

• Stable Demand in Specific Niches: Despite the emergence of newer agents, mezlocillin sodium monohydrate retains a place in specific treatment algorithms due to its established efficacy against certain susceptible pathogens, its historical track record, and its cost-effectiveness in some healthcare systems.
• Cost Sensitivity: In resource-limited settings or for hospitals focused on cost containment, mezlocillin sodium monohydrate, as a generic product, offers an affordable option for treating susceptible infections.
• Hospital Formulary Inclusion: Its continued inclusion on hospital formularies, particularly for specific indications, ensures a baseline level of demand.
• Antibiotic Stewardship Programs: While these programs aim to optimize antibiotic use, they can sometimes lead to the de-escalation to narrower-spectrum agents once susceptibility is confirmed. However, in empirical therapy for serious infections where a gram-negative organism is strongly suspected, mezlocillin might still be considered, especially if cost is a major factor.
• Factors Limiting Growth:
  • Availability of Broader-Spectrum Agents: The widespread availability and clinical preference for piperacillin-tazobactam, carbapenems, and newer cephalosporins will continue to limit mezlocillin's market expansion.
  • Antimicrobial Resistance: Increasing resistance patterns to penicillins can necessitate the use of alternative drug classes.
  • Lack of Novel Development: The absence of significant R&D investment in new mezlocillin-based therapies or formulations limits its potential for market revitalization.
• Market Size Estimation: Global annual sales are estimated to be in the low tens of millions of U.S. dollars. Growth is expected to be flat to slightly negative in developed markets, with potential for marginal growth in emerging markets where cost remains a significant driver.

What are the Manufacturing and Regulatory Considerations?

Manufacturing and regulatory compliance are critical for mezlocillin sodium monohydrate, given its status as a mature, generic drug.

• API Manufacturing: The synthesis of mezlocillin sodium monohydrate involves multi-step chemical processes. Key considerations for API manufacturers include:
  • Yield Optimization: Efficient synthesis pathways to maximize product output and minimize waste.
  • Purity Standards: Meeting stringent pharmacopoeial standards (e.g., USP, EP, JP) for impurities, residual solvents, and degradation products.
  • Supply Chain Reliability: Ensuring a stable and secure supply of raw materials.
  • Cost Control: Continuous process improvement to remain competitive in the generic market.
• Finished Dosage Form Manufacturing: Formulations typically involve sterile powder for injection, requiring aseptic processing and lyophilization.
  • Sterility Assurance: Maintaining sterile conditions throughout the manufacturing process is paramount.
  • Stability: Ensuring the drug product remains stable under recommended storage conditions.
  • Packaging: Appropriate vials and closures to maintain sterility and integrity.
• Regulatory Filings: Manufacturers must secure and maintain approvals from regulatory agencies such as the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and national health authorities.
  • Abbreviated New Drug Applications (ANDAs): For generic versions in the U.S., demonstrating bioequivalence to the reference listed drug.
  • Certificates of Suitability (CEPs): In Europe, for the quality of the API.
  • Good Manufacturing Practices (GMP): Strict adherence to GMP regulations is mandatory for all manufacturing sites.
• Pharmacovigilance: Post-market surveillance for adverse events is required by regulatory bodies.
• Drug Master Files (DMFs): For API manufacturers, filing DMFs with regulatory agencies provides confidential detailed information about manufacturing facilities, processes, and controls.

Key Takeaways

• Mezlocillin sodium monohydrate's patent landscape is characterized by expired foundational patents, with recent filings focused on process improvements and formulations rather than novel API claims.
• The drug experienced peak market share in the late 20th century, with subsequent erosion due to the introduction of newer, broader-spectrum antibiotics.
• Current therapeutic use is primarily for moderate to severe gram-negative bacterial infections in hospital settings, including UTIs, respiratory, and intra-abdominal infections.
• The competitive landscape is dominated by generic manufacturers, facing direct competition from other extended-spectrum penicillins like piperacillin and indirect competition from carbapenems, cephalosporins, and fluoroquinolones.
• Market growth is projected to be flat to slightly negative, driven by stable demand in cost-sensitive markets and specific therapeutic niches, but constrained by antibiotic resistance and the availability of advanced alternatives.
• Manufacturing requires adherence to stringent quality standards (USP, EP, JP) and Good Manufacturing Practices (GMP), with regulatory approvals essential for market access.

Frequently Asked Questions

1. What is the primary difference in spectrum of activity between mezlocillin and piperacillin? Piperacillin generally exhibits a broader spectrum of activity against gram-negative bacteria, particularly Pseudomonas aeruginosa, compared to mezlocillin.

2. Are there any new formulations of mezlocillin sodium monohydrate in development? While significant novel formulation development is not widely reported, existing research focuses on optimizing existing formulations for stability and ease of use in hospital settings.

3. What are the main safety concerns associated with mezlocillin sodium monohydrate? Common side effects include hypersensitivity reactions (rash, urticaria), gastrointestinal disturbances (nausea, diarrhea), and potential for electrolyte imbalances. More serious concerns include neurotoxicity and nephrotoxicity, particularly with high doses or in patients with renal impairment.

4. How does antibiotic resistance impact the use of mezlocillin sodium monohydrate? Increasing resistance of bacterial strains to penicillin-class antibiotics, including mezlocillin, necessitates susceptibility testing and often leads clinicians to choose alternative antibiotic classes with different mechanisms of action.

5. What is the typical route of administration for mezlocillin sodium monohydrate? Mezlocillin sodium monohydrate is administered intravenously (IV) for systemic infections.

Citations

[1] U.S. Patent 3,793,301 A. (1974). Ampicillin derivatives. Retrieved from [Patent Number Search on USPTO Website] (Note: Access to specific patent documents requires direct search on patent office databases). [2] European Medicines Agency. (n.d.). Drug database. Retrieved from ema.europa.eu. [3] U.S. Food and Drug Administration. (n.d.). Drug Search. Retrieved from fda.gov. [4] Lexicomp. (n.d.). Mezlocillin. Retrieved from uptodate.com. [5] Various generic drug manufacturer product inserts and regulatory filings. (Ongoing).