Development of Sustained Released Microparticles of Diclofenac Sodium Using Polymer Complex by Spray Drier

Complex of Carboxymethyl cellulose (CMC) sodium salt and β-cyclodextrin (β-CD) were evaluated as sustained release polymers. Diclofenac sodium (DS), CMC sodium salt and β-CD were taken for the preparation of spray dried sustained release microparticles in the different ratio of 1: 0.125:0.125, 1:0.188:0.187 and 1: 0.25: 0.25 (wt/wt) respectively. The DS loaded microparticles were evaluated for particle size, surface morphology by atomic force microscopy (AFM), structural interaction by Fourier transform infrared spectroscopy (FTIR) and thermal characterization by differential scanning calorimetry(DSC). These microparticles further formulated into the tablet dosage form and evaluated for different parameters. Several kinetic models were employed to evaluate the possible changes in the release mechanism. The drug: polymer ratio of 1:0.25:0.25 shows better result of sustained release than the other ratios. The particle size of the optimized microparticles was found to be in the range of 300 nm to 5 µm. FTIR and DSC result reveals the complex formation between DS, CMC sodium and β-CD. X-ray diffraction results indicated that the degree of crystallinity was reduced and most of the drug existed in amorphous state. . The reported method is easy and reproducible and can be used for the batch scale production.