Lornoxicam Suppositories: In-vitro Formulation and In-vivo Evaluation

The aim of the present study was to formulate lornoxicam into rectal suppositories as a new dosage form, to avoid its reported gastric irritation and to provide a rapid onset of action for children. Suppositories were prepared using fatty bases namely; witepsol H-15, suppocire AML, CM, witepsol E-75 and water soluble bases; mixtures of poly(ethylene glycol), PEGs, with different molecular weights. The prepared suppositories were investigated for their weight variation, drug content, melting point, fracture point, disintegration time and in-vitro release pattern. Moreover, aging study was performed both at room temperature and in refrigerator for 6 month. In-vivo study was also carried out in rabbits and the pharmacokinetic parameters were estimated. The prepared suppositories complied with the USP 34 pharmacopoeial requirements and PEGs-based suppositories released significantly higher amounts of lornoxicam compared with fatty bases (p<0.05, ANOVA/Dunnett). Furthermore, lornixocam in selected formulations was found to be stable in both fatty and PEGs bases after the aging study. Formulation No. 5 showed a higher Cmax of 1.832±0.35 μg/ml, short tmax of 1 hr and absolute bioavailability of 80.1%. These findings suggest that lornoxicam was successfully formulated into rectal suppositories with a higher bioavailability. INTRODUCTION: Lornoxicam (LOR) is considered one of the potent non-steroidal antiinflammatory drugs, NSAIDs, with analgesic and anti-pyretic properties 1 . LOR is structurally related to piroxicam and tenoxicam; however, it is ten times more potent than both of them 2 . Lornoxicam inhibits both cyclooxygenase iso enzymes cox-I and cox-II, hence the gastrointestinal adverse effects still an issue especially with oral