Fig. 3
Turbidity measurements by two methods. a Turbidity of formazin standards (3, 6, 18 and 30 NTU) measured with turbidimeter (FNU in pink) and UV–vis spectrophotometer (relative transmittance in green) T0 = Milli-Q-water (n = 3). b Relationship between measured relative transmittance and FNU of samples of drug: TPNaq (1 + 1) and pure drug solutions. T0 = TPNaq (n = ≥3)