Dissolution rate of chloramphenicol from hard gelatin capsules as a function of type of adjuvants and method of granulation.

The dissolution rate of chloramphenicol from its hard gelatin capsules containing different formulations either in the form of fine powdered blend or granules was investigated. The granules were prepared by the wet method using ethanol 60%, gelatin, carboyme thyl cellulose (CMC) sodium or polyvinylpyrrolidone (PVP) as binders or by slugging at different mechanical strengths. Results showed that the more hydrophilic the formula, the more the dissolution rate of chloramphenicol. Capsules filled with fine powdered blend gave a higher dissolution of the drug than those filled with granules prepared by the wet method or granules prepared from slugs of high mechanical strengths. Of the binding agents tested in the wet method, alcohol excelled gelatin, and the latter excelled CMC sodium and PVP. Capsules filled with granules prepared from slugs of 1 kg hardness gave a dissolution rate which was either higher than or nearly approaching that of capsules filled with the corresponding fine powdered blend.