Items Derivative method (PAR) DD1 method (DPH) Multivariate method Densitometric method Official method [4]*
PAR DPH
PLS PCR PLS PCR PAR DPH PAR DPH
Mean 99.95 99.7 101.00 100.61 100.09 100.40 100.00 100.35 100.11 99.96
SD 1.33 0.99 1.20 1.42 0.75 1.10 0.93 0.86 1.14 1.02
RSD % 1.33 0.99 1.18 1.41 0.74 1.09 0.93 0.85 1.13 1.02
n 6 7 8 8 8 8 7 8 6 7
Variance 1.76 0.98 1.44 2.01 0.56 1.21 0.86 0.73 1.29 1.04
Student's t-test 0.071
(2.22)
0.798
(2.17)
0.943
(2.17)
0.684
(2.17)
0.734
(2.16)
0.108
(2.16)
0.251
(2.20)
0.218
(2.16)
- -
F-value 1.365
(5.05)
1.059
(4.28)
1.107
(4.87)
1.550
(4.87)
1.857
(3.86)
1.928
(4.20)
1.489
(4.38)
1.424
(3.86)
- -
* HPLC method using C18 column , phosphate buffer- acetonitrile (94 :6 by volume) as a mobile phase with UV detection at 225 nm at 4.6 and 8.3 min for PAR and DPH respectively at a flow rate of 1 ml min-1
Table 7: Statistical comparison of the results obtained by the proposed methods and the official method for the determination of pure Paracetamol and Diphenhydramine Hydrochloride.