ABSTRACT
The voltammetric performance of edge-plane pyrolytic graphite [EPG] electrode via adsorptive stripping voltammetry was investigated for study of the electrochemical behavior of omeprazole [OMZ] in aqueous solution. The results revealed that the oxidation of OMZ is an irreversible pH-dependent process that proceeds with the transfer of one electron and one proton in an adsorption-controlled mechanism. The determination conditions, such as the pH values of the supporting electrolyte, accumulation time and scan rate were optimized. Simplicity, high reproducibility and low detection limit [3 nM] of the electrode response as well as wide linear range [0.01 to 4.0 microM] can be stated as significant features of this electrode. The EPG electrode was successfully applied for the determination of OMZ in pharmaceutical formulations and satisfactory results were obtained
Subject(s)
Graphite , Electrodes , ElectrochemistryABSTRACT
Diclofenac sodium as ophthalmic dosage form is used for the treatment of the pain, swelling and redness of patients' eyes recovering from cataract surgery; however, it faces the bioavailability limitation of eye drops due to effective protective mechanisms and corneal barrier functions in the eyes. Therefore, this investigation was aimed to develop ocular film formulations to achieve controlled drug release. Drug films were prepared using polymers, namely hydroxypropyl methylcellulose [HPMC] and polyvinyl pyrrolidone [PVP], Eudragit RL PO, and Eudragit RS PO by solvent casting method considering parameters such as drug: polymer ratio, different polymer combinations as well as plasticizer effect. Ocular films were evaluated for various physicochemical parameters such as physical characters, film thickness, uniformity of weight, drug content, swelling index, mucoadhesion time and in-vitro release study. Ocular films complied with all physicochemical parameters underwent in-vitro release study. Finally, the film formulation with HPMC: Eudragit RS PO 1:1 ratio, Drug: Polymer ratio 1:45 and glycerin as plasticizer showed controlled and prolonged release following the zero order and non-Fickian transport