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Micro vs. nano: PLGA particles loaded with trimethoprim for instillative treatment of urinary tract infections
Bernhard Brauner1, Patrik Schwarz1, Michael Wirth1
1Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Althanstraße 14, 1090 Vienna, Austria.
Abstract:
Recurring infections and increasing resistances continue to complicate treatment of urinary tract infections. To investigate alternative treatment options, trimethoprim loaded micro- (D[4;3] of 1-9 µm) and nanoparticles (Z-Avg of 200-400 nm) were prepared from two types of poly(d,l-lactic-co-glycolic acid) (PLGA) for instillative therapy. While PLGA 503H microparticles could not be loaded with more than 2.6% trimethoprim, PLGA 2300 entrapped 22%. When preparing nanoparticles, both types displayed an even higher drug load of up to 29% using PLGA 2300, while PLGA 503H drug load stagnated at 10%. After eight hours, drug release from microparticles amounted to 55% (503H) and 35% (2300) whereas total drug release occurred after 8 (503H) and 9 days (2300). In case of nanoparticles, trimethoprim was liberated much faster with 60% after 2 h and a complete release after 24 h from both polymers. PLGA 2300 seems to be the better choice for entrapment of trimethoprim in microparticles considering the drug load. Both polymers, however, seem to be viable options for nanoparticles. Due to the higher overall drug load, nanoparticles seem to be advantageous over microparticles for instillative therapy, especially when prepared with PLGA 2300.
Insights
This study developed trimethoprim-loaded micro- and nanoparticles using poly(lactic-co-glycolic acid) for urinary tract infection treatment. Nanoparticles, particularly with PLGA 2300, showed higher drug loading and faster release, indicating potential for effective instillative therapy.
Area of Science:
- Biomaterials Science
- Pharmaceutical Sciences
- Infectious Diseases
Background:
- Urinary tract infections (UTIs) pose significant challenges due to recurring infections and increasing antibiotic resistance.
- Novel therapeutic strategies are crucial for effective UTI management.
Purpose of the Study:
- To develop and evaluate trimethoprim-loaded poly(d,l-lactic-co-glycolic acid) (PLGA) micro- and nanoparticles for instillative therapy.
- To compare the drug loading capacity and release kinetics of different PLGA types and particle sizes.
Main Methods:
- Preparation of trimethoprim-loaded microparticles (1-9 µm) and nanoparticles (200-400 nm) using two PLGA types (503H and 2300).
- Quantification of trimethoprim drug loading efficiency.
- In vitro assessment of trimethoprim release profiles over time.
Main Results:
- PLGA 2300 demonstrated significantly higher trimethoprim loading (22%) in microparticles compared to PLGA 503H (2.6%).
- Nanoparticles exhibited enhanced drug loading (up to 29% with PLGA 2300) compared to microparticles.
- Nanoparticles showed rapid trimethoprim release (60% in 2h, complete in 24h), while microparticles released drugs over days.
Conclusions:
- PLGA 2300 is a preferred polymer for trimethoprim microparticle formulation due to superior drug entrapment.
- Both PLGA types are suitable for nanoparticle formulation, offering rapid drug delivery.
- Trimethoprim-loaded nanoparticles present a promising alternative for instillative UTI therapy, especially when formulated with PLGA 2300.
