Desenvolvimento de metodologia para avaliação da liberação in vitro e controle de qualidade de diclofenaco potássico suspensão oral

Abstract

The diclofenac potassium (DPt) is a derivate of phenylacetic acid, with proprietary anti-inflammatory, analgesic and antipyretic, thus indicated for the relief of low back pain, rheumatoid arthritis and postoperative pain. The DPt is in the market for oral suspension dosage forms, dragee, suppository, injectable solution, dispersible tablet and tablet. However not been found in literature analytical method for determination of DPt in oral suspension. There are also no reports of methods for evaluating the in vitro dissolution of oral suspension containing the drug. Thus, in the present work were developed and validated methods by liquid chromatography high efficiency for the quantification and assessment of drug dissolution in oral suspension. Quantification of DPt was performed using column C8, mobile phase consisting of methanol and phosphate buffer pH 2.5 with a flow rate of 1.0 mL/min. The quantitative method was shown to be specific, even in the presence of possible degradation products, good linearity (r = 1.0), precise (RSD < 2.0%) and having adequate accuracy and robustness. The drug demonstrated to be stable under alkaline conditions and high temperature, but showed instability when exposed to conditions acid, oxidative and in the presence of ultraviolet radiation. To develop the method of dissolving the best conditions were 900 mL of aqueous solution containing 0.3% of sodium laurylsulfate, maintained at 37.0 ± 0.5 ºC, using paddle apparatus with rotation speed of 50 rpm. Thus, the release of DPt was greater than 85.0% at 30 minutes for both batches evaluated. The validated method proved to be specific, linear (r > 0.99), and showed precision and accuracy satisfactory. We also evaluated the stability of the drug in the dissolution medium selected, and the possible adsorption of the drug on the paper filter used. For both the test results were satisfactory. Thus, the methods developed and validated may be used as routine methods in quality control for the quantification and evaluation of the dissolution profile of DPt oral suspension.