Selective spectrofluorimetric determination of two corticosteroids along with their co-formulated drugs and degradation products in ophthalmic solution and aqueous humour.

Prednisolone acetate (PNO) and fluorometholone (FRT) are corticosteroids, co-formulated with moxifloxacin HCl (MFX) and cromolyn sodium (CML), respectively. PNO has a negligible quantum yield and its hydrolytic degradation products have enhanced fluorescence, which is 250-fold greater. FRT is a nonfluorescent drug, but its hydrolytic degradation products show reasonable fluorescence; MFX and CML have native fluorescence. Two methods were proposed based on the determination of PNO and FRT via their hydrolytic degradation products in the presence of other degradation products. Method (A) was developed for simultaneous determination of PNO and MFX in the presence of PNO degradation products by measuring peak amplitudes of the first derivative (1 D) of its enhanced fluorescence; PNO and MFX were measured at 345 and 473 nm, respectively. Method (B) is a synchronous fluorescence spectroscopic method for simultaneous determination of FRT and its co-formulated drug CML in the presence of its degradation products. Fluorescence intensities were measured at λem 283 and 347 nm for FRT and CML, respectively, using Δλ = 99.20 nm. Validation of the proposed methods was conducted as per International Council for Harmonisation (ICH) guidelines. The proposed methods were successfully applied for the determination of the proposed drugs in bulk powder, ophthalmic solution, and rabbit's aqueous humour.

Selective and Sensitive Chromatographic Methods for Determination of a Co-Formulated Binary Mixture in Antibacterial Eye Drops and Aqueous Humor in the Presence of Their Degradation Products and Potential Impurities.

Prednisolone acetate (PDN) is a corticosteroid anti-inflammatory liable to degradation under different conditions and used with antibiotics in eye drops. Two selective stability-indicating separation techniques were developed for simultaneous determination of PDN and moxifloxacin HCl (MXF) binary mixture in pure forms, ophthalmic formulation, in the presence of PDN impurities and in the presence of their degradation products. The first method was based on HPTLC separation using silica gel 60 F254 HPTLC plates, and a developing system of toluene: ethyl acetate: methanol: ammonia (5.0: 6: 2.0: 0.05, v/v/v/v) is used with detection at 254 nm. The second method was HPLC using a mobile phase of acetonitrile: methanol: deionized water, pH 2.8 (25.0: 35.0: 40.0, v/v/v), at 254 nm. A kinetic study utilizing the developed HPLC method for PDN degradation under different stress conditions was performed. Furthermore, the method was applied for determination in rabbit aqueous humor. Validation was conducted as per ICH guidelines, and system suitability was ascertained. The calibration curves were constructed in the range 0.10-25.00 and 0.20-50.00 µg band-1, for PDN and MXF by HPTLC, while for HPLC, it was 0.02-50.00 and 0.10-50.00 µg mL-1 for both drugs, in order.

Resolution and Quantitation of Triamcinolone Acetonide and Its Coformulated Drug in the Presence of Its Impurities and Degradation Products by HPTLC and HPLC.

Two specific, sensitive, and precise stability-indicating chromatographic methods have been developed for the determination of triamcinolone acetonide (TMC) and its coformulated drug, econazole nitrate (ECZ), in the presence of TMC impurities and degradation products. The first method was based on HPTLC-spectrodensitometry in which resolution and quantitation was achieved by using silica gel 60 F254 HPTLC plates and an ethyl acetate-tetrahydrofuran-ammonia mobile phase (10.0 + 7.0 + 0.1, v/v/v). The second method was a reversed-phase HPLC method in which separation was achieved using an acetonitrile-methanol-0.05 M potassium dihydrogen phosphate mobile phase, pH 3.0 (25.0 + 15.0 + 60.0, v/v/v). In both methods, the separated components were detected at 225 nm. Validation of both methods was conducted in compliance with International Conference on Harmonization (ICH) guidelines, and system suitability was confirmed. The linearity ranges were 0.20-28.00 and 0.50-55.00 µg/band for TMC and ECZ by HPTLC, whereas for HPLC, the range was 0.05-30.00 and 1.00-40.00 µg/mL for both drugs, respectively. The methods were successfully applied for the analysis of a pharmaceutical formulation and were compared with the reported method with no significant difference.