Research Of Self-emulsifying Drug Delivery Systems For Piroxicam

Piroxicam is a non-steroidal anti-inflammatory drugs (NSAIDs) that is characterized by low solubility, bioavailability and gastrointestinal irritation after oral administration. when piroxicam was incorporated in self-emulsifying drug delivery systems (SEDDS) or self-microemulsifying drug delivery systems (SMEDDS) and SEDDS pellets, the above problem would be resolved at some extent.To prepare an optimized SMEDDS, the solubility of piroxicam in several oils and surfactants and the compatibility of various oils and surfactants were investigated, and pseudo-ternary phase diagrams were constructed and in vitro properties of formulations were evaluated. In the optimized SMEDDS, m(Cremophor EL): m(Labrafil M 1944CS): m(Transcutol P)=40:50:10. The self-emulsifying time of SMEDDS was less than 1 min, the droplet size distribution and zeta-potential of the resultant microemulsion were 32.2±5.1nm and -5.19mv. The dissolution behavior of piroxicam from SMEDDS exhibited the independence of the kind of medium. The degree of injury of stomach's mucosa was smaller than commercial tablet.The liquid SEDDS were made into SEDDS pellets by extrusion/spheronisation technique. The optimized SEDDS pellets was prepared by single factor test and orthogonal design, in which the self-emulsifying ingredient: MCC ratio was 2:3. The self-emulsifying time was between 20-30 min, and the mean droplet size and zeta-potential of the resultant emulsion were 417.1 nm and -5.52mv respectively. The dissolution behavior of piroxicam from SEDDS pellets exhibited the independence of the kind of medium. Differential Scanning Calorimeter (DSC) was used to investigate the physical characterization of drug in solid SEDDS pellets. The results showed that piroxicam was amorphous in dosage form.The pharmacokinetics of liquid SMEDDS, SEDDS pellet and commercial tablet of piroxicam in beagle dog indicated the oral bioavailability of SMEDDS and SEDDS pellet were improved significantly. Compared with commercial tablet, the relative bioavailability of SMEDDS and SEDDS pellet were (144±24)% and (150±33)%, respectively.