Formulation and Evaluation of Celecoxib –loaded Nanosized Emulsion as Transdermal Drug Delivery Vehicle

Celecoxib, a selective cyclo-oxygenase – 2 inhibitor has been recommended orally for the treatment of arthritis and osteoarthritis. Long term oral administration of celecoxib produces serious gastrointestinal side effects. Therefore the aim of the present investigation was to assess the potential of nanosized emulsion formulations for transdermal delivery of celecoxib (CXB), to reduce the side effects produced by oral administration of the drug, to increase the stability and to produce a novel controlled delivery system with better pharmaceutical and therapeutic properties. Optimized oil in water nanosized emulsion of celecoxib was prepared by ultra sonication method. The prepared nano-sized emulsion was subjected to physical characterization, Drug content analysis and stability tests. Skin permeation mechanism of celecoxib from nanosized emulsion was evaluated by In-vitro skin permeation studies, activation energy measurement and histopathological examination. The anti-inflammatory effects of formulations were compared with marketed formulation by carrageenan-induced paw edema in rats. The nanosized emulsions showed acceptable physical properties and exhibited slow drug release. Photomicrograph of skin sample supports the in-vitro skin permeation data of Celecoxib. The Results revealed that the nanosized emulsion was able to cross the skin and produce expected Anti inflammatory and Analgesic effect. These results suggested that nanosized emulsions can be used as potential vehicles for improved transdermal delivery of Celecoxib. INTRODUCTION: Non steroidal anti-inflammatory (NSAIDs) are the most commonly used drugs to reduce pain and inflammation 1. Celecoxib (CXB), a selective cyclo-oxygenase-2 (Cox-2) inhibitor, has been recommended orally for the treatment of arthritis and osteoarthritis. It is marketed as capsule form of 100and 200mg which possess poor solubility, stability and bioavailability. Long-term oral administration of CXB causes serious gastrointestinal side effects 2 .Therefore, an improved CXB formulation with a high degree of permeation could be useful in the treatment of locally inflamed skin and inflammatory and painful states of body like bones, ligaments etc. One of the most promising techniques for enhancement of transdermal permeation of drugs is the micro emulsion (or) nanoemulsion technique 3, 4. Nano emulsions are thermodynamically stable transparent (translucent) dispersions of oil and water stabilized by an interfacial film of surfactant and co surfactant molecules having droplet size less than 100 nm 5, 6 .This paper describes the potential of the nanosized emulsion system in transdermal delivery of CXB using pharmaceutically acceptable ingredients. The formulation of Celecoxib nanosized emulsion was aimed to reduce the side effects of marketed capsule dosage form, to improve the stability and …