Micromeritic Properties of Nitrofurantoin Microcapsules

WOS: A1995QX96300004In our previous study, we have prepared nitrofurantoin microcapsules using carboxymethylcellulose (CMC) and aluminium sulphate by a coacervation technique. In the present study, the micromeritics of these microcapsules were investigated in terms of standardization of the crude materials employed, the microcapsules product and the dosage forms prepared from these microcapsules. The microcapsules were prepared with a 1:1 core:wall ratio and sieved into three particle sizes. Both the micromeritic properties of the pure drug and the polymer were studied by determining their bulk volume and weight, tapping volume and weight, fluidity, angle of repose, weight deviation, particle size distribution, density and porosity. The particle size range went from approximately 250 mu m to 3000 mu m with a peak between 900 mu m and 1350 mu m. The results indicate that the flowability and the particle size of the resultant microcapsules were much increased compared with the raw materials. As the microcapsule size increases the porosity also increases but the density decreases. The weight deviation of tile microcapsules first sieved then filled into hard gelatin capsules was carried on according to the USP XXII. Hard gelatin capsule size was found by Lindenwald-Tawashi nomogram as number 3. The geometric mean diameters and the geometric standard deviation of microcapsules were calculated as 750 mu m for number distribution and 1275 mu m for weight distribution and 1.52 for number and weight distribution respectively. In addition to evaluate whether some kind of glidant will be needed during tableting of microcapsules and filling of them into hard gelatines, ''Hausner ratio and consolidation indexes'' were calculated. The results obtained suggest that sustained release dosage forms of nitrofurantoin can be prepared from the obtained microcapsules as far as the micromeritic properties is concerned and the microencapsulation changed the micromeritic properties of the crude materials significantly