Prolonged release of pentazocine from multiple O/W/O emulsions

Abstract

Multiple O/W/O emulsions containing pentazocine were prepared and tested in vitro and in vivo. The effect of two different concentrations of three additives, viz. sodium chloride, glucose and glycerol, location of the drug either in one or any two phases of the O/W/O emulsions and pH of the receptor fluid on in vitro release characteristics of the drug was studied. All the parameters influenced the drug release. Multiple O/W/O emulsions gave higher extent of drug release than the simple O/W emulsions. The results of in vivo studies in mice showed prolonged tissue levels of pentazocine from the multiple O/W/O emulsions in comparison to aqueous drug solution and simple O/W emulsion.