A proposal of reference values for relative uncertainty increase in spectrophotometric analysis of pharmaceutical formulations

The LBOZ criterion is an interesting approach for quantifying selectivity during spectrophotometric analysis by measuring the relative uncertainty increase caused by spectral overlapping. Unfortunately, no reference values for pharmaceuticals analysis in the UV region exist. The current paper presents an estimation of the LBOZ distribution as a random variable for binary and ternary drug mixtures. The estimation was done on a representative group of 170 diverse drug-like compounds. Results of the estimation were fitted to the beta and the Johnson distributions. The obtained parameters can be used to examine the “significance” of the spectral overlap by finding the p-value, interpreted as a chance to obtain higher uncertainty increase among the drugs.