Development and validation of a microbiological assay for determination of chlorhexidine digluconate in aqueous solution

Abstract

Chlorhexidine (CHX) is a broad-spectrum antiseptic that is used in many topical pharmaceutical formulations. Because there is no official microbiological assay reported in the literature that is used to quantify CHX, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method for the dosage of chlorhexidine digluconate (CHX-D) in an aqueous solution. The assay is based on the inhibitory effect of CHX-D upon the strain of Staphylococcus aureus ATCC 25923, which is used as the test microorganism. The design 3x3 parallel-line model was used. The results were treated statistically by analysis of variance (ANOVA), and they were excellent in terms of linearity (r = 0.9999), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 0.5 to 4.5%. The results obtained were precise, having relative standard deviations (RSD) for intra-day and inter-day precision of 2.03% and 2.94%, respectively. The accuracy was 99.03%. The method proved to be very useful and appropriate for the microbiological dosage of CHX-D in pharmaceutical formulations; it might also be used for routine drug analysis during quality control in pharmaceutical industries.Uniterms: Agar diffusion. Antiseptic. Chlorhexidine. Microbiological assay. Quality control. Validation.Clorexidina (CHX) é um antisséptico com amplo espectro de ação utilizada em muitos tipos de preparações farmacêuticas para uso tópico. Uma vez que não há na literatura ensaio microbiológico oficial para quantificar a clorexidina, este trabalho objetivou o desenvolvimento e validação de um ensaio microbiológico simples, sensível, exato e reprodutível, por difusão em ágar, para doseamento de digliconato de clorexidina (CHX-D) em solução aquosa. O ensaio é baseado no efeito da inibição de Staphylococcus aureus ATCC 25923, utilizado como microorganismo teste, pela CHX-D. Utilizouse o delineamento 3x3. Os resultados foram verificados estatisticamente pela análise de variância (ANOVA) e apresentaram excelente linearidade (r = 0,9999), demonstrando que o método segue o modelo linear com regressão significativa entre o diâmetro da zona de inibição e o lagaritmo da concentração no intervalo de 0,5 a 4,5%. Os resultados obtidos foram precisos apresentando desvio padrão relativo (DPR) para precisão intra-dia de 2,03% e DPR para precisão inter-dias de 2,94%. A exatidão foi 99,03%. O método provou ser muito útil e apropriado para doseamento microbiológico da CHX-D em formas farmacêuticas e pode ser empregado para análise desta substância no controle de qualidade em indústrias farmacêuticas.Unitermos: Difusão em ágar. Antisséptico. Clorexidina. Ensaio microbiológico. Controle de qualidade. Validação.

Development of a new microbial toxicity test based on inhibition of alpha-amylase production and its sensitivity against metal contaminants

“…The most important criterion to consider in the development of a new bioassay for monitoring toxicant in the environment is reliability (Fiorentino et al, 2013). For bioassay, both sensitivity in detecting the toxicity of contaminants as well as repeatability are required.…”

Rapid determination of nosiheptide in feed based on dispersive SPE coupled with HPLC

“…No significant difference was observed between the two methods. However, microbiological assays are highly variable, difficult to operate, and time consuming, with strict operating requirements . Due to the UV and FL spectroscopic properties of nosiheptide and the sensitivity, selectivity and reliability of HPLC techniques, nosiheptide can be effectively measured using HPLC methods when examining complex matrices such as feed and animal‐derived food.…”

Development and validation of a microbiological assay by turbidimetry to determine the potency of cefazolin sodium in the lyophilized powder form

“…Therefore, bioassays continue to play an essential role in manufacturing and quality control of antibiotic medicines, the association of microbiological assays such as agar diffusion methods or by turbidimetry corroborates better evaluation of the drug. [12][13][14][15][16][17][18][19] Few papers for microbiological analysis of cefazolin sodium are found in the literature. The agar diffusion method was used by Yeh and Chi in 2001 (ref.…”