Table 7 Comparison between the proposed methods and other reported methods used for the assay of erdosteine (ERD).

Spectrophotometry I

Proposed Methods

UV/Visible

-ERD dissolved in Water

-KMnO₄

-NaOH

-λ_max 600 nm

1–6 μg/mL

0.179

μg/mL

0.542

μg/mL

87

Spectrophotometry II

UV/Visible

-ERD dissolved in Water

-Ceric ammonium sulphate

-H₂SO₄

-λ_max320 nm

0.1–1 μg/mL

0.024

μg/mL

0.074

μg/mL

94

Spectrofluorimetry III

Fluoresence

-ERD dissolved in Water

-Ceric ammonium sulphate

-H₂SO₄

-λex 255/λem355

0.01–0.1 μg/mL

0.0027

μg/mL

0.008 μg/mL

94

Spectrofluorimetry IV

Fluoresence

-ERD dissolved in Water

-Acriflavine

-BR-Buffer

-λex 256/λem505

10–100 μg/mL

3.20 μg/mL

9.69 μg/mL

89

Spectrophotometry

⁷

UV/Visible

-Chloranil

-λ_max 454 nm

10–500 μg/mL

–

10 μg/mL

85

Spectrophotometry

⁷

UV/Visible

-TCNQ

- λ_max 843 nm

20–600 μg/mL

–

20 μg/mL

85

HPLC

⁸

UV

*SP:ODS column

*MP: Water– acetonitrile, 0.1% TFA

0.02–6 μg/mL

–

0.02 μg/mL

86

HPLC

¹¹

UV

SP: C18 (4.6 × 250 mm) column

MP: Acetonitrile in phosphate-heptane sulfonate buffer (5:95)

0.5–8 μg/mL

–

0.5 μg/mL

82

HPTLC

¹⁵

Densitometric

SP:Aluminium-packed silica gel 60 F 254 plates

MP: Toluene:methanol:acetone:ammonia (3.5:5:2.5:0.05)

30–1000 ng

–

30 ng

70

UPLC

¹⁷

Fluoresence

SP:C18 column of 150 × 4.6 mm and 3 μm particle size

MP: Methanol:acetonitrile:water (30:30:40)

0.2–3 μg/mL

0.015 μg/mL

0.05

μg/mL

85

UPLC

¹⁶

UV

SP:Waters Acquity UPLC HSS T3, 1.8 µm (2.1 mm × 150 mm, I.D.) column

MP:0.1% TFA in water and methanol

0.06–0.18 μg/mL

0.02 μg/mL

–

85

LC

¹⁴

MS/MS

SP:C18 column

MP: Ammonium acetate-acetonitrile

(80:20)

0.2–5000 ng/mL

–

0.2 ng/ml

88

LC

¹²

MS/MS

SP:Zorbax Eclipse XDB c,( 4.6 × 150 mm,i.d: 5 μm)

MP: Methanol/water/ammonia/formic acid (60:40:0.5:0.01)

0.2–2000 ng/mL

–

0.2 ng/mL

75