Investigation of Acid-Base Indicator Property of Plumbagin from Plumbago zeylanica Linn

Table 7

Effects of the indicator drops on the method robustness.

HCl/NaOH (mL)			CH3COOH/NaOH (mL)			Assay of ibuprofen powder (% purity)			Assay of ibuprofen BP tablets (% content)
3 drops	5 drops	7 drops	3 drops	5 drops	7 drops	3 drops	5 drops	7 drops	3 drops	5 drops	7 drops
10.18	9.99	10.09	11.00	11.08	11.08	98.80	100.30	99.80	99.20	96.00	96.14
10.18	10.09	10.18	11.08	10.90	11.08	99.30	99.80	99.80	98.44	97.82	95.98
10.18	10.09	10.18	11.08	11.00	11.08	98.80	100.30	99.80	98.00	96.87	98.50
10.27	10.09	10.09	11.08	10.90	11.08	99.80	100.30	99.80	96.29	96.80	98.30
10.09	10.18	9.99	11.00	11.00	11.00	99.30	99.80	99.30	96.16	97.67	96.00
10.09	10.18	10.18	10.90	11.08	11.00	99.80	99.80	100.30	97.00	96.90	97.10
Mean = 10.17 ± 0.028	Mean = 10.10 ± 0.029	Mean = 10.12 ± 0.031	Mean = 11.02 ± 0.029	Mean = 10.99 ± 0.033	Mean = 11.05 ± 0.017	Mean = 99.30 ± 0.183	Mean = 100.1 ± 0.112	Mean = 99.80 ± 0.129	Mean = 97.52 ± 0.501	Mean = 97.01 ± 0.270	Mean = 97.00 ± 0.474
RSD = 0.67%	RSD = 0.29%	RSD = 0.31%	RSD = 0.26%	RSD = 0.30%	RSD = 0.15%	RSD = 0.18%	RSD = 0.11%	RSD = 0.13%	RSD = 0.51%	RSD = 0.28%	RSD = 0.49%