direct, rapid and sensitive high - performance liquid chromatographic method for the determination of diclofenac sodium and its application in bioailability studies

A simple [extraction less], rapid and sensitive reversed phase high-performance liquid chromatographic method, with ultraviolet detection at 280 nm, was developed to measure diclofenac sodium in plasma at concentrations suitable for bioavailability studies. Flufenamic acid was used as internal standard and the separation was performed at ambient temperature on a mg-Bondapak C18 column. The mobile phase consisted of a mixture of acetonitrile and 0.05 M phosphate buffer [1:1 v/v]. The pH of the mixture was adjusted to 3.5 using phosphoric acid. The limit of quantitation of diclofenac sodium was 0.05 mug/ml and the time for separation of each sample was no longer than 6.5 minutes at a flow rate of 2 ml/minute. The study of the inter- and intra-day precision and relative recovery study proved that the suggested method is accurate, sensitive and reproducible. The method was applied to test the bioavailability of the enteric coated diclofenac sodium tablets [Voltaren] in Beagle dogs

Formulation and physicochemical evaluation of diclofenac sodium chewable tablets

Taste masked diclofenac sodium, by three techniques, namely microencapsulation with ethylcellulose, ethylcellulose pan coating and 'inclusion complexation with beta-cyclodextrin followed by coating with an aqueous dispersion of ethylcellulose [Aquacoat], was formulated into chewable tablets. After several trials, three formulae, one for each type of the treated diclofenac sodium, were selected. The chosen three formulae were directly compressed into 10 mm diameter flat tablets containing 25 mg of diclofenac sodium and weighing about 600 mg. The produced tablets were evaluated with regard to their taste profile in addition to uniformity of dosage, friability, hardness and dissolution. The obtained results indicated that the three different batches of diclofenac sodium chewable tablets had good to excellent taste except for that based on diclofenac sodium-beta-cyclodextrin inclusion complex. The three batches complied with the pharmacopoeal [USP XXIV] requirements with regard to uniformity of dosage and friability and they showed reasonable hardness values. With regard to the in vitro release profile [in phosphate I buffer pH 7.4], two of the three chewable tablet batches showed fast release profiles, whereas the batch based on diclofenac sodium microcapsulcs showed a relatively slow release pattern