TY - JOUR T1 - Simple HPLC Determination of Benzalkonium Chloride in Ophthalmic Formulations Containing Antazoline and Tetrahydrozoline JF - PDA Journal of Pharmaceutical Science and Technology JO - PDA J Pharm Sci Technol SP - 332 LP - 337 VL - 59 IS - 5 AU - Pornchai Rojsitthisak AU - Wisut Wichitnithad AU - Ongart Pipitharome AU - Kingkan Sanphanya AU - Peeracha Thanawattanawanich Y1 - 2005/09/01 UR - http://journal.pda.org/content/59/5/332.abstract N2 - A simple and rapid analytical procedure for routine quantification of n-C12H25 and n-C14H29 benzalkonium chloride (C-12 and C-14 BKC) homologs in ophthalmic formulations containing antazoline HCl and tetrahydrozoline HCl by high-performance liquid chromatography was developed and validated. The ophthalmic solution samples can be directly analyzed by reversed-phase on HiQ-Sil C18 column (4.6 mm × 150 mm, i.d., 5-μm particle size) with acetonitrile–sodium acetate buffer (pH 5.0; 0.2 M) (70:30, v/v) as mobile phase. UV Detection was carried out at 262 nm. The method was linear over the selected concentration and ranged from 0.03 to 0.10 mg/ml (r2 = 0.9999) and from 0.01 to 0.05 mg/ml (r2 = 0.9979) for C-12 and C-14 BKC homologs, respectively. The mean percent recoveries were 100.2 and 102.6 and the percent CV values were 1.3 and 3.5 for C-12 and C-14 BKC homologs, respectively. The results demonstrated the good linearity, accuracy, and precision. The method was applied to determine two commercial ophthalmic formulations, and the percent label amounts of total BKC contents were found to be 99.7 and 103.2. ER -