Excipients are the integral part of pharmaceutical products development to achieve desired product pro le (stability and efficacy). This review deals with understanding of the physicochemical properties of excipients used in parenteral formulation development for solution, suspension and lyophilized drug products. However, inspite of proper excipients selection, judicious use during formulation manufacturing process based on their critical properties is also important to avoid negative effects such as loss of drug solubility, activity and stability. This paper deals with proper selection of excipients in lyophilized drug products which gives high critical temperature, good bulking properties avoiding melt back and collapse with improved dried product appearance. We have also emphasized on appropriate selection of excipients for solution, suspension injectable dosage forms and linking their physiochemical properties with optimum manufacturing method with suitable case studies. This review will highlight various excipient related issues optimizing product performance with documented references and practical approaches based on scientific justification. The reader will gain better understanding of excipients complexity during stability studies and resolving problems with practical approach.