Stability-indicating RP-LC method for quantification of fusidic acid in cream

ABSTRACT Fusidic acid is an antibiotic steroid indicated for the treatment of infections caused by the genus Staphylococcus, including methicillin resistant Staphylococcus aureus strains, and other Gram-positive bacteria. In the present study, a stability-indicating reversed-phase liquid chromatography (RP-LC) method was developed and validated for the determination of fusidic acid in dermatological cream as an alternative to existing methods. Analyses were performed using a C18 column and guard column at room temperature, eluting with an isocratic mobile phase of acetonitrile and water (72:28, v/v), adjusted to pH 3.5 with acetic acid, pumped at a flow rate of 1.0 mL min-1, detection at 210 nm and 20 µL of injection volume. The forced degradation study was conducted under acidic, alkaline, neutral, photolytic, and oxidative stress conditions. The method was validated according to ICH and FDA guidelines; it was linear, precise, accurate, selective, and robust over concentrations of 5-95 µg mL-1, with detection and quantification limits of 0.43 and 1.31 μg mL-1, respectively. Therefore, we conclude that this method is suitable for quantifying fusidic acid in pharmaceutical dermatological creams and determining its stability, representing a more economical and practical alternative for routine analysis in quality control.

Rapid turbidimetric assay for quantification of fusidic acid in a dermatological cream.

Fusidic acid is an antibiotic steroid widely used for the treatment of serious infections caused by methicillin-resistant Staphylococcus aureus (MRSA) strains. Microbiological methods are indispensable to determine the mean percentage of antimicrobial in medicaments during manufacturing and quality control processes. The aim of this study was to develop and validate a microbiological method for the quantification of fusidic acid in dermatological cream by turbidimetry, using Staphylococcus epidermidis (ATCC 12228) and casoy broth as the culture medium. The validation parameters were in accordance with ICH specifications and demonstrated accuracy, precision, selectivity, and robustness, with linear ranges from 0.25 to 2.25µgmL(-1). This method is an alternative to the diffusion agar assay currently employed to quantify fusidic acid in dermatological cream, since it is sensitive, fast, and more economical.

A Critical Review of the Properties of Fusidic Acid and Analytical Methods for Its Determination.

Fusidic acid, an antibiotic produced from the Fusidium coccineum fungus, belongs to the class of steroids, but has no corticosteroid effects. It is indicated for the treatment of infections caused by methicillin-resistant Staphylococcus aureus strains. The aim of this study was to search for the properties of fusidic acid published so far in the literature, as well as the methods developed for its determination in biological samples and pharmaceutical formulations. From the findings, we can conclude that fusidic acid has been used for decades and is indicated for the treatment of serious infections caused by Gram-positive microorganisms to this day. Furthermore, it is a hypoallergenic agent, has low toxicity, shows low resistance, and has no cross-resistance with other clinically used antibiotics. The analytical method of high-performance liquid chromatography has been widely used for determining fusidic acid, since it can reduce the cost and time of analysis, making it more viable for routine quality control in the pharmaceutical industry.

Periapical Lesions Decrease Insulin Signaling in Rat Skeletal Muscle.

INTRODUCTION: Serum inflammatory cytokines derived from oral inflammation are associated with decreased insulin signaling (IS) and insulin resistance, which is a major risk factor for type 2 diabetes mellitus. This study aimed to investigate IS in the liver and skeletal muscle (SM) and disorders related to the serum lipid profile and glucose and insulin levels of nondiabetic rats with induced chronic periapical lesions (PLs). METHODS: Twenty-eight Wistar rats were divided into control and PL groups. PLs were induced by exposing the pulpal tissue to the oral environment. Experiments were conducted in both groups 30 days after pulp exposure. Maxillae were processed for histopathological analysis. IS was evaluated according to insulin receptor substrate (pp185-insulin receptor substrate 1 [IRS-1]/insulin receptor substrate 2 [IRS-2]) tyrosine phosphorylation status, IRS-1 serine phosphorylation status, and IRS-1 and IRS-2 content in the liver and SM by Western blotting. Serum total cholesterol, triglyceride, glucose, and insulin levels were measured enzymatically using a commercial kit. RESULTS: PL rats showed reduced pp185 P-Tyr and increased IRS-1 serine phosphorylation status in the SM but no change in the liver after insulin stimulation. No significant changes in IRS-1 and IRS-2 content, serum total cholesterol, triglyceride, glucose or insulin levels were noted. CONCLUSIONS: PLs are associated with decreased insulin signaling in the SM of rats. Because a decrease in insulin signaling is associated with insulin resistance, our results emphasize the importance of preventing local inflammatory diseases such as PLs to prevent alterations in IS in muscle.

Periapical lesions decrease insulin signal and cause insulin resistance.

INTRODUCTION: Inflammatory cytokines are associated with decreased insulin signal transduction. Moreover, local oral inflammation, such as that accompanying periodontal disease, is associated with insulin resistance and type 2 diabetes mellitus. The aim of this study was to evaluate the effect of periapical lesions (PLs) on insulin signaling and insulin sensitivity in rats. We hypothesized that PLs alter systemic insulin signaling and insulin sensitivity via elevated plasmatic tumor necrosis factor α (TNF-α). METHODS: Wistar rats were divided into control (CN) and PL groups. PLs were induced by exposing pulpal tissue to the oral environment. After 30 days, insulin sensitivity was measured using the insulin tolerance test. After euthanization, maxillae were processed for histopathology. Plasmatic concentrations of tumor necrosis factor α (TNF-α) were determined via the enzyme-linked immunosorbent assay. Insulin signal transduction was evaluated using insulin receptor substrate tyrosine phosphorylation status and serine phosphorylation status in periepididymal white adipose tissue via Western blotting. For insulin signaling and insulin tolerance tests, the analyses performed were analysis of variance followed by the Tukey post hoc test. For TNF-α analysis, the Student's t test was used. In all tests, P < .05 was considered significant. RESULTS: The rats with PLs showed higher plasmatic TNF-α, lower constant rate for glucose disappearance values, and reduced pp185 tyrosine phosphorylation status but no change in serine phosphorylation status in white adipose tissue after insulin stimulation. CONCLUSIONS: PLs can cause alterations to both insulin signaling and insulin sensitivity, probably because of elevation of plasmatic TNF-α. The results from this study emphasize the importance of the prevention of local inflammatory diseases, such as PLs, with regard to the prevention of insulin resistance.