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Tuesday, 01 July 2014 16:05

Technical Report: Microbiological Quality of LoxaSperse™ Dispersion Evaluated by Mikrocount® Combi


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LoxaSperse is a powder excipient base used for nasal nebulization and irrigation. It is a blend of specially micronized xylitol with an optimized ratio of micronized poloxamers, designed to improve the dispersability and solubility of active pharmaceutical ingredients (APIs) (PCCA, 2013). The use of xylitol and poloxamers in nebulization and irrigation is thoroughly referenced in the literature and there is ample evidence of their safety and efficacy (Durairaj et al., 2006; Jagannath et al., 1995; Plataki et al., 2011; Zabner et al., 2000).

LoxaSperse formulations are dispensed as powders in capsules or sachets without preservatives. Due to an extremely low water activity of less than 0.5, microbiological growth cannot occur in this powder (PCCA, 2013).

At the time of use, the patient must add a predetermined amount of sterile normal saline or sterile water to an appropriate cup, empty the powder contents into the liquid and mix gently to form a dispersion that will be administered via irrigation or nasal nebulization. From the moment of adding water to the powder, the non-sterile LoxaSperse dispersion could possibly become a good environment to support microbial contamination and proliferation.

The aim of this study was to evaluate the capability of the LoxaSperse formulation to remain exempt of microorganisms for 24 h after the non-sterile preparation was mixed with water under realistic conditions for use by the patient, and to draw conclusions about its microbial risk for use in nasal therapy. Fluticasone propionate was chosen as the API in the LoxaSperse formulation tested due to its ample use as a corticosteroid with topical anti-inflammatory effects against asthma (Colice et al., 2013).

Mikrocount® Combi was the microbial monitoring system used in the microbiological assay. It is a simple tool applicable to determine the total number of microorganisms present in any pharmaceutical and cosmetic sample, which provides rapid and reliable microbial control. The simple sampling and evaluation of results through different agar medium for bacteria and fungi confers practicability to a wide scope.



LoxaSperse™ is a powder excipient base used for nasal nebulization and irrigation designed to improve dispersibility and solubility of Active Pharmaceutical Ingredients (APIs). PCCA evaluated the incidence of microbial contamination of a LoxaSperse formulation containing fluticasone propionate for a period of 24 h after the powder was mixed with sterile water under realistic conditions for use by the patient. The resultant LoxaSperse dispersion was subjected to total viable microbial count examination using a Mikrocount® Combi kit. Dip-slide tubes coated on both sides with specific media that allow distinguished bacterial and fungal growth were used in determined time intervals in order to assess the microbiological quality of the preparation. Neither microbial contamination nor physical characteristic changes were detected in the LoxaSperse dispersion containing fluticasone propionate throughout the 24 h study time period. The results showed that this non-sterile pharmaceutical preparation in sterile water avoided microbiological contamination in the absence of a preservative for at least 24 h after formulation reconstitution.


The LoxaSperse formulation containing Fluticasone Propionate 3 mg, as a non-sterile pharmaceutical preparation in sterile water used for nasal nebulization/irrigation, is able to prevent microbial contamination for up to 24 h, making it appropriate for immediate use in nasal nebulization/irrigation. The LoxaSperse dispersion, even without a preservative in its formulation, was free from microbial contamination during the first 24 h after reconstitution under realistic conditions for use by the patient.

Download the complete PDF detailing the results of this study.

Click to learn more about LoxaSperse.