Development and evaluation of a tripartite novel excipient for direct compression of salbutamol tablets

Abstract

The purpose of the study was to develop and evaluate a tripartite novel excipient for direct compression of salbutamol tablets. Various batches (A-E) of the novel excipient was prepared by co-processing varying concentrations of okro gum with gelatinized maize starch and lactose using co-precipitation method. The novel excipient powders were subjected to some physicochemical evaluations. Batches (F-H) of the physical mixture of the novel excipient ingredients were also prepared. The novel excipient and physical mixtures were used to prepare batches of salbutamol tablets by direct compression. The flow properties of their powder mixes and postcompression tablet parameters were evaluated. Drug-novel excipient compatibility was investigated using FTIR. The various batches of the co-processed novel excipient exhibited good flow properties with the following parameters; Carr’s index (≤ 25.30), Hausner’s ratio (≤ 1.25), angle of repose (≤ 25º), swelling index (> 5.22) and hydration capacity (> 4.26). The flow properties were directly proportional to the concentration of okro gum in the excipient or physical mixture. Only batches B-E tablets met official BP specifications with regard to all tablet parameters evaluated. All the batches of tablets exhibited rapid release profiles except batches D and E tablets with some level of slow release. FTIR analyses revealed no interaction between the novel excipient and salbutamol. The co-processed excipient developed in this study was found to be a promising directly compressible vehicle for the preparation of compressed tablets for poorly compressible drugs such as salbutamol.

Keywords: Co-processing, novel excipient, flow properties, post-compression parameters