Development and Validation of Stability Indicating RP-HPLC Method on Core Shell Column for Determination of Degradation and Process Related Impurities of Apixaban—An Anticoagulant Drug

A rapid, specific, sensitive, and precise reverse-phase HPLC method for the quantitative determination of process related and degradation impurities of Apixaban, an anticoagulant drug is described. The developed RP-HPLC method was successfully applied to the analysis of both Apixaban drug substance and drug product. The chromatographic separation was achieved on a Sigma-Aldrich’s Ascentis Express®C18 (4.6 mm × 100 mm, 2.7 μ) HPLC column with a runtime of 40 min. Mobile phase-A and mobile phase-B were phosphate buffer and acetonitrile respectively. The column oven temperature was set at 35°C and photodiode array detector was set at 225 nm. Nine process related impurities (Imp-1 to Imp-9) have been detected in test sample of Apixaban by using newly developed RP-HPLC method. Forced degradation study was carried out under acidic, alkaline, oxidative, photolytic and thermal conditions to demonstrate the stability-indicating nature of the developed RP-HPLC method. The developed method was validated as per ICH guideline and found to be specific, precise, sensitive and robust.

Development and Validation of Stability Indicating HPLC Method for Simultaneous Estimation of Amoxicillin and Clavulanic Acid in Injection

A simple, fast, precise, accurate and rugged stability indicating high performance liquid chromatography (HPLC) method has been developed for simultaneous estimation of Amoxicillin and Clavulanic acid from injectable dosage form. The stability indicating capability of the method was proven by subjecting the drugs to stress conditions as per ICH recommended test conditions such as alkaline and acid hydrolysis, oxidation, photolysis, thermal degradation and resolution of the degradation products formed therein. The separation was obtained using a mobile phase composition at a ratio of 95:5 (v/v) of pH 5.0 buffer and methanol on Inertsil C18 column (250 × 4.0 mm, 4 μm) with UV detection at 220 nm at a flow rate of 1 ml/minute. The photodiode array detector was used for stress studies. The order of elution of peaks was Clavulanic acid followed by Amoxicillin. The linear calibration range was found to be 79.51 to 315.32 μg/ml for Amoxicillin and 17.82 to 67.90 μg/ml for Clavulanic acid. The Amoxicillin and Clavulanic acid were found to be stable in solution up to 24 hours. The method validation data showed excellent results for precision, linearity, specificity, limit of detection, limit of quantification and robustness. The present method can be successfully used for routine quality control and stability studies.

The 144–140 Ma Mafic Dykes in North China and Northeast China Indicating Regional Extensional Tectonic Setting

Objective Previous studies indicate that the North China Craton（NCC）had undergone the loss of thickened lithosphere and fundamental change of physical and chemical property of lithospheric mantle（the destruction of NCC）during the Mesozoic.The peak period of the destruction of NCC is estimated to be 130 Ma,accompanied by widespread metamorphic core complex,rift basins,A-type granites and mafic dykes. However, it remains greatly controversial on the tectonic setting of NCC in the pre- 130Ma.

Development and Validation of Stability Indicating Rapid RP-LC Method for Determination of Process and Degradation Related Impurities of Apremilast, an Anti-Inflammatory Drug

A new, specific, rapid and stability indicating reversed phase liquid chro-matographic (RP-LC) method for the determination of process related and degradation related impurities of Apremilast has been developed and validated. The degradation study performed in acid, base, oxidative, photolytic, and thermal stressed conditions. Eight process related impurities (Imp-1 to Imp-8) in test sample of Apremilast have been detected by developed RP-LC method. The good chromatographic resolution between the peaks of process related impurities, degradation impurities and Apremilast has been achieved on a Synergi Max-RP 80 A (150 × 4.6 mm ID), 4 μ column. The process and degradation related impurities were characterized by mass spectrometry, 1H NMR and FT-IR spectral data. The method was validated as per ICH guideline and found to be specific, rapid, and stability indicating. The proposed RP-PLC method was successfully applied to the analysis of drug substance samples of Apremilast.

New Stability Indicating Method for Quantification of Impurities in Amlodipine and Benazepril Capsules by Validated HPLC

A stability indicating LC method was developed for the simultaneous determination of Amlodipine and Benazepril capsules in pharmaceutical dosage form. Efficient chromatographic separation was achieved on Symmetry C18 stationary phase with simple combination of amobile phase containing 750 mL of DI Water, 250 mL of Acetonitrile and 2 mL of Octylamine into suitable container with adjusted pH to 2.50 ± 0.05 with the aid of Ortho phosphoric acid delivered in an isocratic mode and quantification was carried out using UV detection at 240 nm at a flow rate of 1.0 mL·min-1 with an injection volume of 20 μl and ambient column temperature. This method is capable to detect both the drug components of Amlodipine and Benazepril in presence of their degradation products (Amlodipine Imp-A and Benazepril Impurity-C) with a detection level of 0.05%. Amlodipine/Benazepril in their combination drug product were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions, and the samples were analysed. Peak homogeneity data of Amlodipine and Benazeprilis were obtained using PDA detector, in the stressed sample chromatograms, demonstrating the specificity. The method shows excellent linearity over a range of 0.05%-2.0% for Amlodipine, Amlodipine Impurity-A and 0.05%-5.0% for Benazepril and Benazepril Impurity-C. The correlation coefficient for Amlodipine and Benazepril is 1. The relative standard deviation was always less than 2%. The proposed method was found to be suitable and accurate for quantitative determination and the stability study of Amlodipine and Benazepril in pharmaceutical preparations. The developed HPLC method was validated with respect to linearity & range, accuracy, precision and robustness.

Quantitative Application to a Polypill by the Development of Stability Indicating LC Method for the Simultaneous Estimation of Aspirin, Atorvastatin, Atenolol and Losartan Potassium

Polypill is a fixed-dose combination (FDC) containing three or more drugs in a single pill with the intention of reducing the number of tablets or capsules that need to be taken. Developing a single analytical method for the estimation of individual drugs in a Polypill is very challenging, due to the formation of drug-drug and drug-excipients interaction impurities. Here an attempt was made to develop a new, sensitive, single stability-indicating HPLC method for the simultaneous quantitative determination of Aspirin (ASP) Atorvastatin (ATV), Atenolol (ATL) and Losartan potassium (LST) in a polypill form in the presence of degradation products. Efficient chromatographic separation was achieved on a C18 stationary phase with simple mobile phase combination of buffer and Acetonitrile. Buffer consists of 0.1% Orthophosphoric acid (pH 2.9), delivered in a gradient mode and quantitation was carried out using ultraviolet detection at 230 nm with a flow rate of 1.0 mL/min. The retention times of Atenolol, Aspirin, Losartan potassium, and Atorvastatin were 3.3, 7.6, 10.7 and 12.9 min respectively. The combination drug product are exposed to thermal, acid/base hydrolytic, humidity and oxidative stress conditions, and the stressed samples were analyzed by proposed method. The method was validated with respect to linearity;the method was linear in the range of 37.5 to 150.0 μg/mL for ASP, 5.0 to 20.0 μg/mL for ATV and 25.0 to 100.0 μg/mL for ATL and LST. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. The validated method was successfully applied to the analysis of Starpill tablets constituting all the four drugs;the percentage recoveries obtained were 99.60% for ASP, 99.30% for ATV, 99.41% for ATL and 99.62% for LST.

A Stability Indicating U-HPLC Method for Milnacipran in Bulk Drugs and Pharmaceutical Dosage Forms

The objective of the current study was to develop a validated, specific and stability-indicating reverse phase UHPLC method for the quantitative determination of Milnacipran and its related substances. The determination was done for active pharmaceutical ingredient and its pharmaceutical dosage forms in the presence of degradation products, and its process-related impurities. The drug was subjected to stress conditions of hydrolysis (acid and base), oxidation, pho- tolysis and thermal degradation per International Conference on Harmonization (ICH) prescribed stress conditions to show the stability-indicating power of the method. Significant degradation was observed during acid, base, oxidative and neutral stress hydrolysis. The chromatographic conditions were optimized using an impurity-spiked solution and the samples generated from forced degradation studies. In the developed UHPLC method, the resolution between Milnacipran and its process-related impurities was found to be greater than 2.0. Regression analysis shows an r value (correlation coefficient) of greater than 0.999 for Milnacipran and it’s all the five impurities. The chromatographic separation was achieved on a C18 stationary phase. The method employed a linear gradient elution and the detection wavelength was set at 220 nm. The mobile phase consists of buffer and acetonitrile delivered at a flow rate of 0.2 mL?min–1. Buffer consists a mixture of 10 mM Sodium dihydrogen phosphate monohydrate and 10 mM hexane sulfonate sodium salt, pH adjusted to 2.5 using ortho phosphoric acid. The mobile phase A consists of buffer and acetonitrile (950:50, v/v) and mobile phase B consists of acetonitrile. The stress samples were assayed against a qualified reference standard and the mass balance was found to be close to 99.5%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness.

Potentiometric Determination of Chloride and Cyanide Ions in Nanoliter Samples with Capillary Indicating Electrodes

The samples of 25 nL of chloride and cyanide were determined with a kind of glass capillary indicating electrodes by potentiometry. Silver was deposited by the silvermirror reaction on the inner surface of the glass capillary with a volume of 25 nL. The AgCl film and the AgI film were formed by the treatment of the capillary with a FeCl 3 solution and further with a KI solution. The samples were collected automatically into the capillary by the capillary ascension. The procedure in the measurement was merely to place a reference electrode and a capillary indicating electrode vertically on a strip filter paper containing a 01 mol/L NaNO 3 solution. The various i.d. of the capillary electrodes were used to determine samples ranging from 25 nL to dozens of microliters. The ranges of the linear response to chloride and cyanide were 32×10 -4 —22×10 -1 mol/L and 10×10 -5 —10×10 -1 mol/L with an average slope of 552 and 52—62 mV/decade , respectively. The samples with various concentrations of chloride and cyanide were determined, and the relative standard deviations were less than 7%.

Stability indicating high performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in combined dosage form

A specific, precise and stability indicating high-performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in pharmaceutical formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F254 as the stationary phase. The solvent system consisted of methanol：water：ammonium acetate; 4.0：1.0：0.5 （v/v/v）. This system was found to give compact and dense spots for both itopride hydrochloride （Rf value of 0.55__＋0.02） and pantoprazole sodium （Rf value of 0.85＋0.04）. Densitometric analysis of both drugs was carried out in the reflectance- absorbance mode at 289 nm. The linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9988___0.0012 in the concentration range of 100--400 ng for pantoprazole sodium. Also, the linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9990_＋0.0008 in the concentration range of 200-1200 ng for itopride hydrochloride. The method was validated for specificity, precision, robustness and recovery. Statistical analysis proves that the method is repeatable and selective for the estimation of both the said drugs. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method.

A Validated Stability Indicating RP-UPLC Method for Atrovastain Calcium

The present paper describes stability indicating reverse phase Ultra performance liquid chromatographic (RPLC) assay method for Atrovastatin Calcium in bulk drugs. The developed method is also applicable for the related substance determination and degradation products generated from forced decomposition studies. The drug substance was subjected to stress conditions of acid hydrolysis, base hydrolysis, oxidation, photolysis and thermal degradation. The degradation of Atrovastatin was observed under acid hydrolysis, base hydrolysis and peroxide hydrolysis. The drug was found to be stable to other stress conditions attempted. Successful separation of the drug from synthetic impurities and degradation product formed under stress conditions was achieved on a C18 column using buffer 0.02 M phosphoric acid and acetonitrile. The developed UPLC method was validated with respect to linearity, accuracy, precision, specificity and ro-bustness. The developed UPLC method to determine the related substances and assay determination of Atrovastatin can be used to evaluate the quality of regular production samples. It can be also used to test the stability sample of Atrovastatin Calcium.

Development and Validation of Stability Indicating HPTLC Assay for Determination of Gemifloxacin Mesylate in Dosage Forms

Simple and sensitive stability-indicating high performance thin layer chromatography (HPTLC) assay was developed and validated for quantitative determination of the antibacterial drug, gemifloxacin mesylate (GFX) in presence of its degradation products and ambroxol hydrochloride. The chromatographic separation was performed on HPTLC precoated silica gel plate 60F254 as stationary phase. The mobile phase consisted of a mixture of ethyl acetate: methanol: 25% ammonia, (8:4.5:3, v/v/v). The detection was performed using fluorescence mode and the emission intensity was measured using optical filter K400 after excitation at 342 nm. The Rf value for GFX was 0.47 ± 0.03. Good correlation coefficient was obtained over the concentration range of 1.5 - 180 ng/band. The LOD and LOQ of the proposed method were 0.28 and 0.86 ng/band, respectively. The proposed method was successfully applied for the analysis of GFX in its single and combined dosage forms. Moreover, it was utilized to investigate the kinetics of acidic, alkaline, neutral, oxidative and photolytic degradation of the drug. The apparent kinetic-order rate constants and half-life times of the degradation process were calculated. Furthermore, the proposed method was successfully applied for investigating the factors affecting the storage of GFX.

Development and Validation of Stability Indicating RP-HPLC-PDA Method for Tenatoprazole and Its Application for Formulation Analysis and Dissolution Study

In the present study, comprehensive stress testing of tenatoprazole was carried out according to ICH guide-line Q1A (R2). Tenatoprazole was subjected to stress conditions of hydrolysis, oxidation, photolysis and neutral decomposition. Extensive degradation was found to occur in acidic, neutral and oxidative conditions. Mild degradation was observed in basic conditions. The drug is relatively stable in the solid-state. Successful separation of drug from degradation products formed under stress conditions was achieved on a Kromasil C18 column (250 mm × 4.6 mm, 5.0 μ particle size) using methanol: THF: acetate buffer (68:12:20 v/v) pH adjusted to 6.0 with acetic acid as mobile phase, flow rate was 1.0 mL●min–1 and column was maintained at 45°C. Quantification and linearity was achieved at 307 nm over the concentration range of 0.5 - 160 μg●mL–1 for tenatoprazole. The method was validated for specificity, linearity, accuracy, precision, LOD, LOQ and robustness.

Degradation Pathway for Pitavastatin Calcium by Validated Stability Indicating UPLC Method

Degradation pathway for pitavastatin calcium is established as per ICH recommendations by validated and stability indicating reverse phase liquid chromatographic method. Pitavastatin is subjected to stress conditions of acid, base, oxidation, thermal and photolysis. Significant degradation is observed in acid and base stress conditions. Four impurities are studied among which impurity-4 is found prominent degradant. The stress samples are assayed against a qualified reference standard and the mass balance is found close to 99.5%. Efficient chromatographic separation is achieved on a BEH C18 stationary phase with simple mobile phase combination delivered in gradient mode and quantification is carried at 245 nm at a flow rate of 0.3 mL min-1. In the developed UPLC method the resolution between pitavastatin calcium and four potential impurities is found to be greater than 4.0. Regression analysis shows an r value (correlation coefficient) of greater than 0.998 for pitavastatin calcium and four potential impurities. This method is capable to detect the impurities of pitavastatin calcium at a level of 0.006% with respect to test concentration of 0.10 mg/mL for a 2-μL injection volume. The developed UPLC method is validated with respect to specificity, linearity & range, accuracy, precision and robustness for impurities determination and assay determination.

A Stability Indicating HPLC Method for Dronedarone in Bulk Drugs and Pharmaceutical Dosage Forms

The objective of the current study was to develop a validated, specific and stability-indicating reverse phase HPLC method for the quantitative determination of Dronedarone and its related substances. The determination was done for active pharmaceutical ingredient and its pharmaceutical dosage forms in the presence of degradation products, and its process-related impurities. The drug was subjected to stress conditions of hydrolysis (acid and base), oxidation, photolysis and thermal degradation per International Conference on Harmonization (ICH) prescribed stress conditions to show the stability-indicating power of the method. Significant degradation was observed during acid, oxidative and photo stress studies. In the developed HPLC method, the resolution between Dronedarone and its process-related impurities was found to be greater than 2.0. Regression analysis shows an r value (correlation coefficient) of greater than 0.999 for Dronedarone and it’s all the five impurities. The chromatographic separation was achieved on a C8 stationary phase. The method employed a linear gradient elution and the detection wavelength was set at 288 nm. The stress samples were assayed against a qualified reference standard and the mass balance was found to be close to 99.6%. The developed HPLC method was validated with respect to linearity, accuracy, precision and robustness.

Rapid Validated Stability Indicating Method for Nizatidine and Its Impurities Quantification

This research article describes stability indicating fast liquid chromatographic method for determination of chromatographic purity and assay of Nizatidine as a alternate for two different methods for chromatographic purity and assay as given in USP Monograph and Ph.Eur Monograph. Proposed method is developed on Waters symmetry RP18 (50 × 4.6 mm), 3.5 μm stationary phase using gradient elution with combination of Ammonium acetate Diethyl amine buffer, Methanol and Tetrahydrofuran as mobile phase. Favorable results are obtained under developed conditions, which guarantee good separation of studied components. Whereas, data obtained from method validation confirm specificity, high sensitivity, linearity in a range of studied concentrations, repeatability and good accuracy of this method. Considerable degradation observed in oxidation stress condition was detected by this method. Eight impurities are studied among which impurity-5 is found major degradant. The stress samples are assayed against a qualified standard and the mass balance is found close to 99.2%. The developed method can be used for routine samples as well as stability studies.

Stress Degradation Behavior of a Polypill and Development of Stability Indicating UHPLC Method for the Simultaneous Estimation of Aspirin, Atorvastatin, Ramipril and Metoprolol Succinate

A novel, sensitive and precise UHPLC method has been developed and validated for the simultaneous determination of the all the active components of a Polypill viz Zycad, i.e., Aspirin (ASP) Atorvastatin (ATV), Ramipril (RMP) and Metoprolol (MTP) in Zycad tablet dosage form in the presence of degradation products. Forced degradation of individual as well as combination of all the drug substances components of Polypill was conducted in accordance with ICH guidelines. Acidic, basic, neutral, and oxidative hydrolysis, thermal stress, and photolytic degradation were used to assess the stability-indicating power of the method. Use of 100 × 2.1 mm, 1.7 μm stationary phases with simple mobile phase combination buffer consisting of 0.1% Perchloric acid (adjusted to pH 2.5) and Acetonitrile, delivered in a gradient mode and quantitation was carried out using ultraviolet detection at 215 nm with a flow rate of 0.6 mL?min–1. The method was optimized using samples generated by forced degradation studies. The method was validated for linearity, accuracy (recovery), precision, Specificity and robustness. The method was linear in the range of 37.5 to 150.0 μg?mL–1 for ASP, 5.0 to 20.0 μg?mL–1 for ATV and 2.5 to 10.0 μg?mL–1 for RMP and 25.0 to 100.0 μg?mL–1 for MTP.

A Validated Stability Indicating LC Method for Amlexanox in Bulk Drugs

A novel and sensitive stability indicating RP-HPLC method has been developed for the quantitative determination of amlexanox in bulk drugs. The separation was accomplished on C18 column using 10 mM ammonium dihydrogen orthophosphate (pH adjusted to 4.8 by using ortho phosphoric acid) and methanol (30:70 v/v) as mobile phase in an isocratic elution mode at a flow rate of 1.0 mL min-1. The eluents were monitored by PDA detector at 245 nm. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Significant degradation was found under basic, acidic stress and UV light. The resolution (Rs) between amlexanox and its degradation products was found to be greater than 2.5. Regression analysis shows correlation coefficient greater than 0.999 for amlexanox. The inter and intraday precision values for amlexanox were found to be within 1.0% RSD. The method has shown good and consistent recoveries for amlexanox in bulk drugs (98.86% - 101.05%). The developed method was validated with respect to linearity, accuracy, precision and robustness.

A Stability Indicating Reverse Phase-HPLC Method Development and Validation for the Estimation of Bimatoprost 0.3% &Timolol 0.5% Pharmaceutical Ophthalmic Dosage Form

The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmic solution method development was determined on Waters HPLC instrument using a UV Detector. The separation was done by using L11, Zorbex SB phenyl (4.6 mm × 250 mm internal diameter) 5 μm analytical column, containing mobile phase of Phosphate buffer (0.02 M), methanol, and acetonitrile [50:30:20 % v/v]. The method was run at 1 ml·min-1 at 210 nm for Bimatoprost and 295 nm for Timolol for detection. The drug was eluted at 10.81 min for Bimatoprost and 3.77 min for Timolol. After developing the method, it was assured for the intended use by validation, which was done according to ICH Q2B guidelines. The analytical parameters checked were Specificity/Selectivity, linearity, Range, accuracy, ruggedness, and robustness. It was observed that the response of the detector was linear in the range of 6 - 18 μg/ml with a correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability-indicating assay method was established by using the samples generated by the forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative, and photolytic degradation, and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the quantitative analysis of Bimatoprost 0.3% + Timolol 0.5% Ophthalmic Solution drugs for pharmaceutical use. Currently, there is no official method for Bimatoprost & Timolol combination products in USP or BP. Available research work related to single Bimatoprost or Timolol products was not suitable for testing Bimatoprost and Timolol combination drugs. Additionally, there is no stability-indicating method to test Bimatoprost & Timolol combination products which insist us to do research and develop a new reverse phase-HPLC indicating method which will be faster and more accurate.

Development and validation of a stability-indicating RP–HPLC method for estimation of atazanavir sulfate in bulk

A stability-indicating reverse phase–high performance liquid chromatography（RP–HPLC） method was developed and validated for the determination of atazanavir sulfate in tablet dosage forms using C_（18） column Phenomenix（250 mm×4.6 mm, 5 μm） with a mobile phase consisting of 900 mL of HPLC grade methanol and100 mL of water of HPLC grade. The pH was adjusted to 3.55 with acetic acid. The mobile phase was sonicated for 10 min and filtered through a 0.45 μm membrane filter at a flow rate of 0.5 mL/min. The detection was carried out at 249 nm and retention time of atazanavir sulfate was found to be 8.323 min. Linearity was observed from 10 to 90 μg/mL（coefficient of determination R^2 was 0.999） with equation, y=23.427x＋37.732.Atazanavir sulfate was subjected to stress conditions including acidic, alkaline, oxidation, photolysis and thermal degradation, and the results showed that it was more sensitive towards acidic degradation. The method was validated as per ICH guidelines.

Identification of Colored Dyes that are Resistant to Fading on Exposure to Ethylene Oxide;Use with Indicating FTA™Sample Collection Cards

Regulatory Standards and Forensic Communities are expressing an expectation for HID products to be certified as“DNA‑free.”Recently,“DNA‑free”status was described for HID‑related products using ethylene oxide(EtO);this gas reduces the presence of amplifiable DNA and causes minimal interference to downstream HID‑analytical methods.During sample collection,indicating cards,for example,Indicating FTA™(GE Healthcare Life Sciences,UK),are used to collect and store buccal cell DNA.These cards contain a dye which changes color on application of a colorless sample.Generating“DNA‑free”indicating cards using EtO should not impact the dyes’ability to indicate sample location or the efficacy of the card in downstream HID‑analytical methods.This study was initiated to identify alternative dyes to those currently used with sample indicating collection cards.The most promising,dyes when applied to cellulose papers exhibited a uniform color distribution and excellent sample indicating properties even when mixed with chemicals associated with FTA™.When dyed cellulose papers were exposed to EtO,ultraviolet radiation,elevated temperature,and humidity,negligible fading or discoloration was observed.The presence of these dyes on cellulose papers did not interfere with direct short tandem repeat(STR)profiling.Allelic concordance,first pass success rate,and mean peak heights were comparable to samples applied to Indicating FTA.Biological samples applied to EtO‑treated dyed cellulose papers and stored>1 month produced full STR profiles of sufficient quality to allow submission to DNA databases,confirming negligible interference from EtO treatment.These alternative sample indicating dyes resist EtO‑mediated fading while fulfilling the Forensic Community’s expectation for“DNA‑free”with negligible impact on collection card performance.