Chemical stability and in vitro antimicrobial efficacy of diluted silver sulfadiazine powder and cream over a six-month period.

Autor: Lopresto CM; Pet Allergy & Dermatology Specialists, Allentown, Pennsylvania, USA., Palmeiro BS; Pet Allergy & Dermatology Specialists, Allentown, Pennsylvania, USA., Cole SD; Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA., Xu X; Pennsylvania Animal Diagnostic Laboratory System, Toxicology Laboratory, New Bolton Center, Kennett Square, Pennsylvania, USA., Dietrich J; Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA., Stefanovski D; Department of Clinical Studies, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, Kennett Square, Pennsylvania, USA.
Jazyk: angličtina
Zdroj: Veterinary dermatology [Vet Dermatol] 2024 Dec; Vol. 35 (6), pp. 704-715. Date of Electronic Publication: 2024 Aug 19.
DOI: 10.1111/vde.13289
Abstrakt: Background: Silver sulfadiazine (SSD) is commonly formulated into otic preparations to treat otitis externa, although evidence of stability and antimicrobial efficacy with long-term storage is lacking.
Objectives: To evaluate the effect of storage time on chemical stability and in vitro antimicrobial activity of SSD diluted in sterile water, including two 1% suspensions using SSD pharmaceutical-grade powder stored at room temperature (RT) in plastic or sterile glass bottles, and a 1:9 dilution using prescription SSD 1% cream stored at RT in a sterile glass bottle.
Materials and Methods: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assessed chemical stability. Trimethoprim/sulfamethoxazole-susceptible and trimethoprim/sulfamethoxazole-resistant strains of Staphylococcus pseudintermedius (SP), meticillin-resistant (MR) SP, S. schleiferi (SS), MRSS, Pseudomonas aeruginosa, Proteus mirabilis and Escherichia coli evaluated by 24 h time-kill analysis assessed in vitro antimicrobial efficacy. Each assessment was performed at zero, one, three and six months of storage.
Results: LC-MS/MS showed no significant change in concentration over time for any suspension. When adjusted for time and species/strain, all SSD suspensions showed significant reductions in colony forming units (cfu)/mL at 24 h (p < 0.001). Including all suspensions, a bactericidal effect (minimum 3-log cfu/mL reduction at 24 h) occurred against 94% of total isolates, with failure against 33 of 552 isolates (6%). Bactericidal failure was more likely with the cream-based suspension (p < 0.05) and at six months (p < 0.01).
Conclusions and Clinical Relevance: Powder-based and cream-based SSD/sterile water suspensions showed no significant change in concentration and demonstrated in vitro antimicrobial activity for six months. Bactericidal failure was more likely with the cream-based suspension and after six months of storage.
(© 2024 ESVD and ACVD.)
Databáze: MEDLINE
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