Formulation Development of Gentamicin Sulphate Ointment Using Rice Bran Wax as Novel Base for Topical Application

The present study aims to investigate the possible use of rice bran wax as novel and cost effective oil in water emulsion (O/W) type of ointment base. Thus the formulations were prepared by incorporating different combinations of Rice bran wax, white petrolatum and cetostearyl alcohol. Gentamicin sulphate was used as a model drug. All the formulations were evaluated for different physicochemical parameters such as, pH, spreadability, skin irritation studies, drug content, rheological studies, in-vitro drug release studies, microbiological studies and stability studies. The optimized preparations were compared with ointment prepared from carnauba wax and also the marketed formulation. The stability studies of prepared ointments revealed that formulation F1 syneresis whereas other formulations were physically stable and syneresis was not observed. No significant changes were observed in pH and viscosity values of stable formulations. The formulations were within the permissible limits of all physical parameters. The microbiological studies revealed that the inhibition zone diameters of prepared formulations were comparable to inhibition zone diameters shown by ointment prepared from carnauba wax and marketed preparation. Thus it can be concluded that rice bran wax can be used as ointment base as well as it can be explored as a cost effective excepient in other pharmaceutical preparations.