A simple Eco-Friendly Novel Estimation of Folic Acid in pharmaceutical preparations and environmental wastewater samples: Application to Content Uniformity Testing

Rahman Ahmed N and Naif Rahman G

Published on: 2024-12-28

Abstract

A simple, accurate, precise, rapid, economical and sensitive spectrophotometric method has been developed for the determination of Folic acid in pharmaceutical preparations and environmental wastewater samples, which shows maximum absorbance at 283 nm in 0.1 N Sodium hydroxide. Beer's law was obeyed in the range of 0.2-1.6 mg/100 ml ,with  molar absorptivity of 2.258x105  L.mol-1.cm-1 , relative standard deviation of the method was less than 1.2%, and accuracy (average recovery %) was 100 ± 1.0  .The method was successfully applied to the determination of Folic acid in pharmaceutical formulations (tablets),application to content university testing , and industrial wastewater samples. The proposed method was validated by sensitivity, and precision which proves suitability for the routine analysis of Folic acid in true samples.

Keywords

Folic acid; Spectrophotometry; Pharmaceutical preparations; Environmental samples; Content uniformity testing

Introduction

Folic acid (FA) it is one of the types of B vitamins, which is vitamin B9 and is considered one of the most important vitamins beneficial to the human body Folic acid is  N-4-(2-Amino-4-hydroxyptered-6-ylmethylamina)ben-zoyl-L-glutamic acid ,as shown below (Figure 1) Folic Acid occurs as a yellow to orange-yellow, crystalline powder. It is odorless. It is practically insoluble in water, in methanol, in ethanol (95), in pyridine and in diethyl ether .It dissolves in hydrochloric acid, in sulfuric acid, in dilute sodium hydroxide TS and in a solution of sodium carbonate dehydrate (1 in 100), and these solutions are yellow in color. Folic acid is one of the B vitamins, also referred to as vitamin B9 and folacin [1-4].

Molecular Formula: C19H19N7O6=441.4

Figure 1: Chemical Structure of Folic Acid.

Literature survey reveals that numerous methods have been published for quantitative analysis of Folic acid alone and in combination with other drugs such as high performance liquid chromatography HPLC [5-8], various spectrophotometric methods [9-12], derivative spectrophotometry [13-15], differential  pulse voltammeter [16], Electrochemical determination [17] and capillary electrophoresis with chemiluminescence detection [18].These methods are required expensive or sophisticated instruments and not simple for routine analysis . The present paper reports the development of a new spectrophotometric method for determination of Folic acid in pharmaceutical formulations (tablets) and environmental water samples. The aim of this study is to use the method (visible spectrophotometer) this method features a reaction with high sensitivity, accuracy, and very simple, inexpensive instrumentation and does not require the high expertise of the analyst in the laboratory.

Experimental

Apparatus

Shimadzu UV-1700 pharm aspect (double beam) spectrophotometer with 1.0 cm quartz cells was used for absorption measurement.

Reagents

All chemical used were of analytical or pharmaceutical grade and Folic acid standard material and pharmaceutical preparations (tablets) was provided from Al-Hokama company for pharmaceutical industries Mosul-Iraq 0.1 N Sodium hydroxide was used as a solvent.

Folic acid standard solution 10ppm

This solution was prepared by dissolving 15 mg of Folic acid in 1000 ml of 0.1 N Sodium hydroxide in calibrated flask.

Determination of absorption maxima

The standard solution of Folic acid (1.5mg/100ml) was scanned in the range of 220-325 nm which shows maxima located at 283 nm Figure 2. Therefore, 283 nm wavelength was selected for the construction of calibration curve.

Figure 2: Absorption Spectra of 1.5mg/100ml Folic Acid Against. 0.1 N Sodium Hydroxide.

Recommended Procedure

From the absorption maxima,calibration curve was prepared in the concentration range of 0.2-1.6 mg/100ml .The absorbance was measured at 283 nm against 0.1 N Sodium hydroxide as a blank .The concentration of the sample solution can be determined by using the calibration curve       

Procedures for Pharmaceutical Preparations (Tablets)

To minimize a possible variation in the composition of the [Tablets 0.5 mg/tab] were provided from Al-Hokama company for pharmaceutical industries (Mosul-Iraq) .Ten tablets were weighed and amount of tablet powder equivalent to 1.5 mg of Folic acid was weighed accurately and dissolved in about 80 ml of 0.1 N Sodium hydroxide, mixed well for 20 min and then filtered. The filtrate was made up to 100mL with0.1 N Sodium hydroxide  .The final concentration is 1.5 mg /100ml. and aliquot of this solution was treated as described above for recommended procedure and the concentration was calculated by using the calibration curve of this method.

Procedure for Real Water Samples

To demonstrate the practical applicability of the proposed method, real water samples were analyzed by this method. Industrial waste water from AL-hokamaa company for pharmaceutical industries (HPI) Mosul-Iraq, were fortified with the concentrations in the range of 0.5, 1.0, 1.6 mg/100ml of Folic acid. The fortified water samples were analyzed as described above for recommended procedure and the concentration was calculated by using the calibration curve of this method.

Results and Discussion

UV- Visible spectrophotometry is still considered to be a convenient and low cost method for the determination of pharmaceuticals [19-26].  This method used for the determination of Folic acid in pharmaceutical preparations and environmental wastewater samples was found to be sensitive, simple, accurate and reproducible .Beer s law was obeyed in the concentration range of 0.2-1.6 mg/100ml Figure 3 with correlation coefficient of 0.9997, intercept of 0.0096 and slope of 0.5163. The conditional molar absorptivity was found to be 2.258x105   l/mol.cm.

Figure 3: Calibration Curve for Folic Acid.

The accuracy and precision of the method, a pure drug solution was analyzed at three different concentrations, each determination being repeated six times. The relative error (%) and relative standard deviation values are summarized in (Table 1).From table 1 the values of standard deviation were satisfactory and the recovery studies were close to 100%. The RSD% value is less than 1.6 indicative of accuracy of the method.

Table I: Accuracy and Precision of the Proposed Method.

Folic acid taken mg/100ml))

Er (%)a

RSD (%)

0.5

1

1.3

1

0.92

1.6

61

0.82

1.5

a: Mean of six determinations

Analytical Application

The proposed method was satisfactorily applied to the determination of Folic acid in its pharmaceutical preparations Tablets and wastewater samples, the results of the assay of the pharmaceutical preparations revels that there is close agreement between the results obtained by the proposed method and the label claim. As cited in Table [2], and the results of water samples Table [3] show that the recovery values obtained were closed to 100%.

Table2: Determination of Folic Acid Formulations.

Recovery%

Label amount

Proposed method found*

Pharmaceutical formulations

99.8

0.5mg/tab

0.499

Folic acid tablet (0.5mg/table)

*Mean of ten determinations

Table 3: Determination of Folic Acid in Industrial Wastewater Samples.

Wastewater samples

Added  mg/100ml

Found*  mg/100ml

Recovery %(n=10)

Industrial wastewater

0.5

0.503

100.6

1

0.997

99.7

1.6

1.608

100.5

*Mean value of ten determinations

Application of the Proposed Method to Content Uniformity

Content uniformity or the Uniformity of dosage unit was defined as the degree of uniformity in the amount of active substance among dosage units. The risk assessment strategy underlying content uniformity testing is the assumption that some pre-specified limits exist where safety and efficacy outcomes may change if content uniformity fails [27]. The proposed method proved to be suitable for the content uniformity test, where a great number of assays on individual tablets are required. Data presented in table 4 indicate that the proposed method cans accurately and precisely quantitative losartan potassium in its commercially available tablets. The mean percentage (with RSD) of the labeled claim found in ten tablets was 100.06(0.313%) which fall within the content uniformity limits specified by the United State Pharmacopeia [28-32].

Table 4: Content Uniformity Testing of Tablets Using the Proposed Method.

Parameter

% of the label claim

Table No.1

100.5

Table No.2

99.7

Table No.3

100.4

Table No.4

100.3

Table No.5

99.6

Table No.6

100.1

Table No.7

99.8

Table No.8

100.2

Table No.9

100,2

Table N0.10

99.8

Mean(X)

100.06

%RSD

0.313

Max. allowed unit value[28]

±15%

Conclusion

The developed method is found to be high sensitive, accurate, simple, precise and economical, and can be used for routine quality control analysis of Folic acid in pure form, pharmaceutical formulations and environmental wastewater samples.

Acknowledgments

The author’s wishes to express gratitude to Al-Hokama company for pharmaceutical industry (HPI) (Nineveh – Iraq.) for providing gift samples of Folic acid standard material and for per¬mission and facilities to carry out the research work. Providing waste water samples and for permission and facilities to carry out the research work.

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