Development and Validation of Novel Spectrophotometric Methods for the Determination of Ethacridine Lactate in Bulk

¹Cheif Operating Officer, Veeda CR, Ahmedabad, Gujarat, India. 

²KVSR Siddhartha College of Pharmaceutical Sciences, Vijayawada - 520 010, India.

Corresponding Author E-mail: drgdr1964@gmail.com

DOI : http://dx.doi.org/10.13005/msri/070220

Three simple and sensitive visible spectrophotometric methods (A-C) for the determination of Ethacridine Lactate in pure samples and pharmaceutical formulations are described. They are based on the formation of colored species by treating with Folin-Ciocalteau reagent (Method A, λ_max 600nm) or 3-methyl 2-benzathiazolinone hydrazone in the presence of Ferric chloride (Method B,  λ_max 580 nm), or 1, 10 Phenathroline in presence of Ferric chloride (Method C, λ_max 490nm). These methods were extended to the analysis of pharmaceutical preparations and results are compound with the refernce method (USP).

Introduction

Ethacridine lactate^1,2 (EAL) is chemically 2-ethoxy-6, 9-diamino acridine monolactate monohydrate. It is used as an antispetic and also as an agent for second trimester tabortion.³ A survey of literature revealed only a few reported methods which include titrimetric,⁴ selective FTIR,⁵ visible spectrophotometry⁶ and HPLC methods for estimation of EAL in urine.⁷ The analytically important groups of EAL were not exploited for designing suitable spectrophotometric methods. Hence an attempt has been to develop simple and sensitive visible spectrophotometric methods for EAL determination for routine quality control analysis of EAL in formulations.

The developed methods are based on the formation of colored species by treating with Folin-Ciocalteau reagent (Redox reaction),⁸ 3-methyl 2-benzathiazolinone hydrazone in the presence of Ferric chloride (Oxidative coupling)⁹ or 1, 10 Phenanthroline in presence of Ferric chloride (Oxidation followed by complexation).¹⁰

Experimental

Instrument

A systronics model 220 UV-Vis spectrophotometer with 1cm matched quartz cells were used for absorbance measurements

Reagents

All the chemicals used were of Analytical grade and prepared with double distilled water Aqueous solutions of FC reagent (2N) and 20% w/v Sodium carbonate solutions were used for Method A

Aqueous solutions of MBTH (0.2% w/v) and 0.01 % w/v Ferric chloride solutions were used for Method B.

1, 10 Phenanthroline Solution (0.198% w/v)

Prepared by dissolving 198 mg of 1, 10 Phenathroline in 0.1 N HCl and made upo the mark with 0.1 N HCl.

Ferric chloride solutions (0.0033M)

About 162 mg of anhydrous Ferric chloride was accurately weighed and dissolved in 100 ml of distilled water. 33.3 ml of above stock solution was further diluted to 100 ml with water.

Standard Drug Solution

Working standard solution of EAL was prepared by dissolving 10ml of the drug solution (1mg/ml) in water and made upto the mark of 100 ml with water (100 µg/ml).

Method A

Aliquots of standard EAL solution (100 µg/ ml) ranging from 0.5 to 2.5 ml were transferred to a series of 10 ml volumetric flasks. To each flask 3 ml of Sodium carbonate solutions and 1ml of FC reagent were added and kept aside for 5 min. The volume was made upto 10 ml with 0.1 N HCl. The absorbance was measured at 600 nm against reagent blank. The amount of EAL was deduced from its Beer-Lamberts plot.

Method B

Aliquots of standard EAL solution (100 µg/ml) ranging from 0.15 to 0.9 ml were transferred to a series of 10 ml volumetric flasks. To each flask 2 ml of Feeric chloride solutions and 1ml of MBTH reagent were and allowed to stand at room temperature for 15 min. The volume was made upto 10 ml with 0.1 N HCl. The absorbance was measured at 580 nm against reagent blank. The amount of EAL was deduced from its Beer-Lamberts plot.

Method C

Aliquots of standard EAL solution (100 µg/ml) ranging from 0.2 to 1.0 ml were transferred to a series of 10 ml volumetric flasks. To each flask 1 ml of Feeric chloride solutions and 1ml of 1, 10 Phenanthroline reagent were and the volumes in all the flasks were equalized with ethanol. The contents were gently boiled for 35 minutes, cooled to room temperature and 2ml of o-Phosphoric acid was added to all the flasks. The volume was made upto 10 ml with ethanol. The absorbance was measured at 490 nm against reagent blank. The amount of EAL was deduced from its Beer-Lamberts plot.

For Pharmaceutical Formulations

For injection formulations, 10 vials were broken and the constent were transferred to a clean and dried beaker. From this a volume of the drug solution equivalent to 100 mg of EAL was taken and a standard stock solution of 1mg/ml was prepared. This was appropriately diluted and the amount of EAL was found out as described in the procedure.

Recovery Study

To study the accuracy, reproducibility and precision of the proposed methods, recovery experiments were carried out. The recovery of the added standard was studied at 3 different levels. Each level was repeated 6 times. A plot of amount of drug found by proposed method (Y-axis) against standard added (X-axis) was drawn. The inrercept on Y-axis indicates the amount of drug present per formulation.

Results and Discussion

Table 1: Optical Regression characteristics of proposed methods

Click on image to enlarge

Table 2: Results of assay and recovery experiments

Click on image to enlarge

References

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