RP- HPLC Method for Simultaneous Determination of Moxifloxacin HCL And Dexamethasone Sodium Phosphate in Bulk and In Ophthalmic Solution

Abstract

A RP-HPLC method for the simultaneous estimation of MOX and DSP in bulk drug and in combined ophthalmic solution has been developed. Separation of the drugs were carried out on the Qualisil C₈ (5 μ, 250 mm × 4.60 mm) column at ambient temperature using a mobile phase consisting of methanol and water (75: 25, v/v), pH of mobile phase adjusted to 3. Flow rate was 1.0 mL/min & detection was carried out at 240 nm. The average retention time for MOX and DSP was found to be 2.22, and 7.26 min, respectively. The calibration range was 10 – 60 mg/mL (r² = 0.999) for MOX and 2 - 12 mg/mL (r² = 0.999) for DSP, respectively. The method has successively been applied for determination of MOX and DSP in combined ophthalmic solution. There was no interference from the excipients commonly present in the ophthalmic solution. The drug contents for MOX and DSP was found to be 99.97 % and 99.68 %, respectively. The % recovery was found to be within the limits of the acceptance criteria with average % recovery 99.35 - 100.79 % (MOX) and 99.43 - 99.96 % (DSP). Precision of the method was studied as intra-day, inter-day and repeatability, the % RSD value for each parameter was found to be less than 2, indicate high precision of the method. For MOX, LOD and LOQ was found to be 0.30 mg & 0.91 mg, respectively. For DSP, the LOD and LOQ was found to be 0.10 mg & 0.30 mg. According to USP, system suitability tests are an integral part of chromatographic methods. They are used to verify the reproducibility of the chromatographic system. To ascertain its effectiveness, system suitability tests were carried out on freshly prepared stock solutions.