2.2.1. Preparation of econazole nitrate nanoparticles
The econazole nanoparticles were prepared by nano-spray drying technique. Weighed amounts of econazole nitrate, carriers and stabilizers (table 1) were dissolved in ethanol (10 ml) followed by spraying through the Buchi® nano-spray dryer B-90 (Büchi Labortechnik, Switzerland). The nano-spray dryer was operated using inert loop B-295 system (Büchi Labortechnik AG, Flawil, Switzerland) operated using nitrogen gas with flow rate of 110 L/min. The spray drying processes were operated at an inlet temperature of 90°C and an outlet temperature of 35°C with a feeding rate of 40 mL/hr. The spray mesh with 7.0 μm aperture size was used in our study. The obtained nanoparticles were collected …show more content…
Evaluation of econazole nitrate nanoparticles
2.2.2.1. Determination of nano-spray drying process yield
The econazole nanoparticles collected from nano-spray dryer were weighed and the yield was calculated by the following equation:
% Yield=(Recovered mass)/(Mass entered in the spray dryer)×100
2.2.2.2. Determination of drug content
The drug content of the formulations was determined by dissolving accurate amount of econazole nitrate nanoparticles in ethanol and the concentration of econazole nitrate was then measured at 271 nm by Shimadzu 1800 UV (Japan). All nanoparticles preparations were tested for percentage drug content using the following equation:
% Drug content=(Actual drug amount)/( Therotical drug amount)×100
2.2.2.3. Percent drug loading
Econazole nitrate nanoparticles were weighed and then dissolved in ethanol to determine the amount of drug in them using Shimadzu 1800 UV (Japan) measured at 271 nm. The percent drug loading was calculated using the following equation:
% Drug loading=(Amount of drug in nanoparticles)/( Weight of nanoparticles)×100
2.2.2.4. Determination of particle …show more content…
2.2.3. Stability of econazole nitrate nanosuspensions
All the prepared econazole nitrate formulations were dispersed in isotonic buffer pH 7.4 and measured for their particle size, polydispersity index (PDI) and zeta potential values during 6 months of storage at room temperature using time intervals of 0, 1, 2, 3, 9, 12, 19, 33, 62, 92, 122, 152 and 182 days. On the other hand, the optimum formulation was tested for its particle size stability till one year of storage at room temperature.
2.2.4. In-vitro drug release study
The prepared econazole nitrate nanoparticles obtained from the nano-spray dryer were suspended in isotonic buffer pH 7.4 and were then tested for drug release by dialysis method in isotonic buffer with pH of 7.4. Nanoparticles (equivalent to 2.5 mg of drug) were instilled in dialysis bag containing 1 ml isotonic buffer with pH value of 7.4 and was secured by two clamps at each end. The dialysis bag was completely soaked in a vessel containing 100 ml of release medium with shaking rate of 200 stroke per min and maintaining at 34oC (incubator shaker IKA KS 4000, Germany). The vessel was closed to avoid evaporation of the release medium. Samples were taken at certain time intervals. The samples were measured spectrophotometrically at 221.5 nm using Shimadzu 1800 UV (Japan). Release efficiency