Validated HPLC method for quantifying permethrin in pharmaceutical formulations

Simultaneous Determination of Fipronil, Permethrin, and Their Key Related Substances in a Topical Drug Product by a Single Stability-Indicating High-Performance Liquid Chromatography Method

BACKGROUND

The topical veterinary drug product containing fipronil and permethrin provides an effective repellent protection and high insecticidal efficacy for dogs.

OBJECTIVE

The objective of this study was to develop a stability-indicating high-performance liquid chromatography (HPLC) method for simultaneous detection and quantification of fipronil, permethrin, their key degradation products, and butylated hydroxytoluene (BHT) in a topical drug product.

METHOD

The two active ingredients, their degradation products, and the antioxidant (BHT) were separated by a gradient elution on a Phenomenex Kinetex C18 column (150 × 3 mm, 2.6 µm particle size) maintained at 37°C with H2O acetonitrile isopropyl alcohol 85% H3PO4 (65.5 + 32.5 + 4/0.0053, v/v/v/v) as mobile phase A and acetonitrile (100%) as mobile phase B. The flow rate was 0.9 mL/min, and analytes were detected and quantified at 235 nm.

RESULTS

The specificity of the method was demonstrated by adequate separation of fipronil, permethrin, their degradation products, and BHT in the forced degraded finished product. The linearity of the method was demonstrated in the range of 0.2% to 150% of target analytical concentration of both active ingredients and 50% to 150% for BHT. Excellent recoveries of fipronil, permethrin, and BHT in placebo spiked active ingredient solutions in the linearity range showed sufficient accuracy of the method. The LOQ and LOD of the method were determined to be 0.2% and 0.07% of the analytical concentration. A robustness study did not identify any critical parameter that adversely affected the separation and quantification.

CONCLUSIONS

Here, we report the development and validation of a robust, stability-indicating HPLC method for identification and assay of fipronil, permethrin, and BHT, including estimation of fipronil's and permethrin's degradation products in a topical drug product for dogs.

HIGHLIGHTS

The new HPLC method permits the acquisition of data for all analytes of interest for a topical finished drug product containing fipronil, permethrin, and BHT.

Extraction of permethrin from impregnated fabrics for determination by ultra-high performance liquid chromatography with diode array detection

Permethrin is a synthetic pyrethroid insecticide that is largely used in the impregnation of fabrics employed for different purposes. This paper reports a detailed study on the conditions for its extraction from fabrics and for its determination by ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD). Several parameters that could affect the extraction efficiency of permethrin were evaluated, such as the extraction time, agitating mode (mechanical or ultrasound-assisted), solvent type (methanol or acetonitrile), concentration, and volume. Under optimized conditions, the extraction was performed for 10 min using a 2 × 2 cm piece of impregnated fabric and 5 mL of pure methanol. The flask containing the sample and the solvent was shaken mechanically using a horizontal roller mixer. The accuracy of the method was assessed by a recovery test, which presented satisfactory results ranging from 86.8% to 95.2%. The method was employed in the analysis of nine samples of commercial fabrics of different colors and grammages that were impregnated with permethrin. The concentration of permethrin found in these samples varied between 25.6 ± 4.2 and 934 ± 119 mg m^-2.

A cell-based potentiometric biosensor using the fungus Lentinus sajor-caju for permethrin determination in treated wood

The characteristics of a potentiometric biosensor for the determination of permethrin in treated wood based on immobilised cells of the fungus Lentinus sajor-caju on a potentiometric transducer are reported this paper. The potentiometric biosensor was prepared by immobilisation of the fungus in alginate gel deposited on a pH-sensitive transducer employing a photocurable acrylic matrix. The biosensor gave a good response in detecting permethrin over the range of 1.0-100.0 µM. The slope of the calibration curve was 56.10 mV/decade with detection limit of 1.00 µM. The relative standard deviation for the sensor reproducibility was 4.86%. The response time of the sensor was 5 min at optimum pH 8.0 with 1.00 mg/electrode of fungus L. sajor-caju. The permethrin biosensor performance was compared with the conventional method for permethrin analysis using high performance liquid chromatography (HPLC), and the analytical results agreed well with the HPLC method (at 95% confidence limit). There was no interference from commonly used organophosphorus pesticides such as diazinon, parathion, paraoxon, and methyl parathion.

Reaction of 2,6-dichloroquinone-4-chloroimide (Gibbs reagent) with permethrin - an optical sensor for rapid detection of permethrin in treated wood

Background

A novel optical sensor for the rapid and direct determination of permethrin preservatives in treated wood was designed. The optical sensor was fabricated from the immobilisation of 2,6-dichloro-p-benzoquinone-4-chloroimide (Gibbs reagent) in nafion/sol–gel hybrid film and the mode of detection was based on absorption spectrophotometry. Physical entrapment was employed as a method of immobilisation.

Results

The sensor gave a linear response range of permethrin between 2.56–383.00 μM with detection limit of 2.5 μM and demonstrated good repeatability with relative standard deviation (RSD) for 10 μM at 5.3%, 100 μM at 2.7%, and 200 μM at 1.8%. The response time of the sensor was 40 s with an optimum response at pH 11.

Conclusions

The sensor was useful for rapid screening of wood or treated wood products before detailed analysis using tedious procedure is performed. The validation study of the optical sensor against standard method HPLC successfully showed that the permethrin sensor tended to overestimate the permethrin concentration determined.

An Ecofriendly and Stability-Indicating HPLC Method for Determination of Permethrin Isomers: Application to Pharmaceutical Analysis

A green, simple, and stability-indicating RP-HPLC method was developed for simultaneous determination of permethrin isomers in pharmaceutical preparations. The separation was based on a C18analytical column (150 × 4.6 mm, i.d., 5 μm). The mobile phase consisted of ethanol: phosphoric acid solution (pH = 3) (67 : 33, v/v). The elution was carried out at 30°C temperature with a flow rate of 1.0 mL/min. Quantitation was achieved with UV detection at 215 nm. In forced degradation studies, the drug was subjected to oxidation, hydrolysis, photolysis, and heat. The method was validated for specificity, linearity, precision, accuracy, and robustness. The applied procedure was found to be linear in permethrin concentration range of 0.5–50 μg/mL with correlation coefficients of 0.9996 for each isomer. Precision was evaluated by replicate analysis in which % relative standard deviation (RSD) values for areas were found below 2.0. The recoveries obtained (99.24%–100.72%) ensured the accuracy of the developed method. The peaks of permethrin isomers well resolved from various degradation products as well as the pharmaceutical excipients. Accordingly, the proposed validated and sustainable procedure was proved to be proper for routine analyzing and stability studies of permethrin in pharmaceutical preparations.

Development and validation of a 'universal' HPLC method for pyrethroid quantification in long-lasting insecticidal mosquito nets for malaria control and prevention

OBJECTIVES

To outline the development and validation of a universal method for quantifying deltamethrin, permethrin and alpha-cypermethrin levels in a variety of long-lasting insecticidal mosquito nets.

METHODS

Using the HPLC conditions found in the CIPAC method for deltamethrin quantification, the method is based on a simple extraction technique for sample preparation (heating in isooctane at approximately 100 °C for 15 min). The method was validated for linearity, specificity, accuracy, precision, insecticide stability to extraction conditions and required extraction time for insecticide removal.

RESULTS

The method was found valid for insecticide quantifications for various types of nets, namely for deltamethrin coated on polyester nets, deltamethrin incorporated into polyethylene nets, permethrin incorporated into polyethylene nets, alpha-cypermethrin coated on polyester nets and alpha-cypermethrin incorporated into polyethylene nets.

CONCLUSIONS

This method will provide a more simplified approach to testing a variety of nets (different types of fibre) containing deltamethrin, permethrin or alpha-cypermethrin.

Fast and universal HPLC method for determination of permethrin in formulations using 1.8-μm particle-packed column and performance comparison with other column types

An HPLC method has been developed for the fast separation and quantification of permethrin using C18 column packed with 1.8 µm particles. The method is specific with good resolution to degradation products and to other present components. It has acceptable validation results. The run time is 4.5 min (or may be within 1.6 min is rapid resolution mode) with an organic solvent consumption of 3.6 mL per run. The method has been applied to samples of formulations for various uses: mattress cleaner, shampoo, and veterinary powder. The performance of the applied column is compared with other common column types. The relationships between linear velocity of the mobile phase (u) and resolution factor (Rs), back-pressure (ΔP), and efficiency (H) are presented. The experimental data shows the advantages of 1.8-µm particle columns to be a significant reduction in solvent consumption (by factor of 4.4 and 1.5) and a reduction in run-time (by factor 4.7 and 1.5), and the weaknesses are a high back-pressure and lower efficiency. Finally, it has been shown that use of 1.8-µm particle packed columns with conventional HPLC systems is possible, but with limitations in mobile phase flow-rate.

Formation of supramolecular permethrin/β-cyclodextrin nanorods

Molecular dynamics simulations along with scanning tunneling microscopy (STM) imaging demonstrate the formation of a novel type of nanorods, with a stable [permethrin(beta-CD)(2)](n) structure in which the host:guest ratio is 2:1 and n=21-27 giving a length of approximately 30.0-38.5 nm and an average diameter of approximately 1.5 nm, self-assembled from an inclusion complex composed of permethrin and biocompatible beta-cyclodextrin.

Bioactive Permethrin/β-Cyclodextrin Inclusion Complex

Permethrin is popularly used in a variety of therapeutic areas. However, the poor water solubility of permethrin seriously limits its wider clinical applications. The present study demonstrates that solubility of permethrin in aqueous solution can considerably increase in the presence of beta-cyclodextrin (beta-CD). Extensive experimental data along with computational modeling reveal the formation of stable permethrin/beta-CD inclusion complexes, including permethrin(beta-CD) and permethrin(beta-CD)2, through hydrophobic binding. Both permethrin(beta-CD) and permethrin(beta-CD)2 complexes coexisted in aqueous solution, and the ratio of the concentration of permethrin(beta-CD) complex to that of permethrin(beta-CD)2 complex was dependent on the concentration of beta-CD. The complexation of permethrin with beta-CD significantly improved the bioavailability of permethrin and, therefore, increased the bioactivity. The significant increase of the bioactivity of permethrin in the presence of beta-CD provides an effective approach to improve the practical use of permethrin in public health and agriculture.

Solid-phase microextraction (SPME) of permethrin residues from cucumber using a silica-bonded phase-coated stainless steel fibre

Solid-phase microextraction (SPME) is a rapid, economic and solvent-free sample preparation method for the isolation of an analyte from its matrix. The technique uses a few centimetres of some adsorptive materials such as activated charcoal, polydimethylsiloxane or octadecyl silane coated onto fused silica optical fibres or, more recently, stainless steel fibres mounted into a microsyringe. The proposed method allows the extraction of permethrin from cucumber matrix into the coating, avoiding sample handling and saving evaporation of solvents and concentration steps. Adsorbed permethrin was desorbed in the split/splitless injection port of the gas chromatograph. The time required for each run was about 1.5 h, which gave a preconcentration of several orders of magnitude. The method could separate and quantify cis- and trans-isomers of permethrin. The calibration curve showed linearity in the range 1-9 micrograms ml-1, with detection limits of 0.03 and 0.05 microgram ml-1 for the cis- and trans-isomers of permethrin, respectively. The method had a recovery rate of about 70% and a relative standard deviation of less than 13%. Results suggest that this procedure provides a rapid and sensitive alternative method to those currently available.

An overview of the recent trends in development of HPLC methods for determination of impurities in drugs

An extensive survey of the literature published in various analytical and pharmaceutical chemistry related journals has been conducted and the high-performance liquid chromatography (HPLC) methods which were developed and used for determination of process-related impurities in drugs have been reviewed. This review covers the time period from 1995 to 2001 during which around 450 analytical methods including all types of chromatographic and hyphenated techniques were reported. HPLC with UV detection was found to be the technique of choice for many workers and more than 200 methods were developed using LC-UV alone. A critical analysis of the reported data has been carried out and the present state-of-art of HPLC for determination of impurities of analgesic, antibiotic, anti-viral, anti-hypertensive, anti-depressant, gastro-intestinal and anti-neoplastic agents has been discussed.

Combined exposure to DEET (N,N-diethyl-m-toluamide) and permethrin: pharmacokinetics and toxicological effects

Permethrin and DEET are concurrently used for pests control inside homes, in public places, and in military shelters. Combined exposure to these compounds produced greater biochemical, behavioral, and metabolic alterations in animals compared to each individual compound. Concurrent application of DEET and permethrin induced urinary excretion of 3-nitrotyrosine and 8-hydroxy-2'-deoxyguanosine, markers of DNA damage and oxidative stress in rats, increased the release of rat brain mitochondrial cytochrome c, disrupted the blood-brain barrier (BBB) in rats, decreased m2 muscarinic acetylcholine receptor ligand binding density in rat brain, increased urinary excretion of 6 beta-hydroxycortisol, a marker CYP3A4 induction, altered sensorimotor and locomotor activities in rats, and changed in vivo and in vitro metabolism and pharmacokinetic profiles of the individual compound. These findings show that more research is needed to examine adverse effects of the combined use of DEET and permethrin on other biochemical/physiological system(s) and to predict mechanistic pathways for these effects, particularly mechanism of action at cellular and molecular levels and alterations of genes transcription.