A Sensitive Spectrophotometric Estimation of Nimodipine in Tablets and Injection Using Phloroglucinol

Table 1

Comparison of the performance characteristic of the existing visible spectrophotometric methods with the proposed methods.

Sl no.	Reagent/s used	Methodology	Linear range 𝜇g/mL and molar absorptivity L/moL/cm	Remarks	References
(1)	4-Dimethylaminobenzaldehyde in methanol	Condensation product was measured at 580 nm	—	Requires heating condition	[11]
(2)	N-(1-naphthyl)ethylenediamine dihydrochloride	Colored azo dye was measured at 550 nm	0–40.0	Less sensitive	[12]
(3)	(a) p-Dimethylaminocinnamaldehyde; (b) Folin Ciocalteu reagent	The absorbance of Schiff base was measured at 510 nm; The colored complex was measured at 640 nm	0.5–4.0; 5.0–25.0	Sensitive but uses costly reagent; Lack of selectivity	[13]
(4)	𝛽-Naphthol	Orange-red colored azo dye measured at 555 nm	0–10.0; (€=7.74×10^2)	Less sensitive	[14]
(5)	Metol-dichromate	Charge transfer complex measured at 520 nm	0–70.0; (€=3.15×10^3)	Less sensitive and requires strict pH control	[15]
(6)	Phloroglucinol	Yellow colored azo dye measured at 410 nm	0–25; (€=1.23×10^4)	Highly sensitive and has wider linear dynamic ranges	Proposed method