Densitometric and videodensitometric determination of nadolol and pindolol in tablets by quantitative HPTLC

New, simple, precise, and rapid high performance thin layer chromatography (HPTLC) methods have been developed for the determination of nadolol (N) and pindolol (P) in tablets. The stationary phase was silica gel 60F(254) and the mobile phase was ethyl acetate-methanol-glacial acetic acid (49 + 49 + 2, v/v). Detection and quantification were done densitometrically at 270 nm and by videodensitometric scanning at 254 nm. In a densitometric procedure, the linearity range was 0.2-1.2 mug/10 muL for N and P. In a videodensitometric assay, the linearity ranges were 2.0-12.0 and 0.2-1.2 mug/10 muL for N and P, respectively. Precision was validated by replicate analyses of standard solutions, and accuracy by analysis of fortified samples. In densitometric procedure, the precision (RSD) obtained for the standard solutions ranged from 1.14 to 2.80 and from 0.74 to 1.85% for N and P, respectively. For the videodensitometric assay, the RSD values ranged from 0.68 to 2.36 and from 0.79 to 3.20% for N and P, respectively. The results obtained by both techniques were compared.