Dissolution Test of Cefadroxil Capsules

The dissolution patterns of cefadroxil in capsules were examined according to the JP X dissolution test. Cefadroxil capsules of brands A and B exhibited low dissolution rates of the drug and no disintegration was observed in 60 min. On the other hand, another lot of each brand supplied subsequently showed rapid disintegration and the dissolution of the drug almost completed in 30 min. A hydrophobic lubricant, magnesium stearate and the like was considered to suppress the disintegration and the dissolution of the drug in the former cases.It was also found that vigorous shaking of the capsules suppressed the disintegration and the dissolution of the drug in one lot of capsules which showed rapid disintegration and dissolution of the drug before shaking.It was, therefore, concluded that the dissolution of cefadroxil in capsules can be remarkably suppressed when a hydrophobic lubricant is used. It is important to control carefully the amount of the lubricant, mixing time of a mixture of drug, diluent, and lubricant before packing, and the physical condition at the time of transportation or storage.