The objective of this study was to develop two simple and selective visible spectrophotometric methods for the determination of antihistamine drug triprolidine hydrochloride (TRH) in the capsules. The methods were based on the formation of ion-pair complexes between TRH and two dyes, namely, bromocresol green (BCG) and bromophenol blue (BPB). The produced ion-pair complexes were measured at 415 and 410 nm for BCG and BPB methods, respectively. Beer’s law was applicable in the concentration ranges of 2.50-15.0 μg mL-1 TRH for both methods. The molar absorptivity values were found to be 2.12 × 104 and 2.07 × 104 L mol-1 cm-1 for the BCG method and BPB method, respectively, and the Sandell’s sensitivity values were 0.0149 and 0.0152 μg cm-2. The limits of detection and quantification were calculated and found to be 0.29 and 0.86 μg mL-1 for the BCG method and 0.31 and 0.95 μg mL-1 for the BPB method. The methods were applied successfully for TRH determination in bulk drug and in the capsules. (TRH capsules ionpair ion pair dyes namely (BCG BPB. . (BPB) 41 respectively Beers Beer s 2.5015.0 250150 2.50 15.0 2 50 15 0 2.50-15. mL1 mL 1 mL- 212 12 2.1 10 207 07 2.0 mol1 mol mol- cm1 cm cm- Sandells Sandell 00149 0149 0.014 00152 0152 0.015 cm2. cm2 2. cm-2 029 29 0.2 086 86 0.8 031 31 0.3 095 95 0.9 (BPB 4 5015 2.5015. 25015 250 2.5 150 15. 5 2.50-15 21 20 0014 014 0.01 0015 015 02 0. 08 8 03 3 09 9 501 2.5015 2501 25 2.50-1 001 01 0.0 2.501 2.50- 00

Three simple methods are described for the determination of amoxicillin (AMX) in bulk drug and dosage forms using iodate-iodide mixture reagent. These methods employed the well-known analytical reaction between iodate-iodide mixture in the presence of acid solution. The iodide oxidized by iodate to iodine in an amount equivalent to the -COOH group present in amoxicillin (AMX) and the liberated iodine determined by titrimetry and spectrophotometry. In the titrimetric method (method A), the liberated iodine was reacted with a measured excess of thiosulphate and the residual thiosulphate was determined by titration with a standard iodine solution using starch indicator, the method was applicable over 2 - 16 mg of AMX. In the second and third methods, the absorbance of the liberated iodine was measured at 370 nm (method B) and also iodine was reacted with starch and starch-iodine complex was measured at 570 nm (method C). In spectrophotometric methods (B and C), Beer’s law was obeyed over the concentration range of 5 - 50 and 5 - 60 µg mL-1 AMX with a molar absorptivity values of 5.55×103 L mol-1 cm-1 and 4.76×103 L mol-1 cm-1 for the method A and method B, respectively. The limits of detection (LOD) and quantification (LOQ) were calculated for method B and method C. The proposed methods were found to yield reliable results when applied to bulk drug and dosage forms analysis, and hence they can be applied in quality control laboratories.