Formulation, development and evaluation of injectable formulation of Aspirin

The objective of this study was to develop and manufacture a stable parenteral formulation for Aspirin, a non steroidal anti-inflammatory agent. The solubility and stability of the drug was determined. Solubility studies suggested that Aspirin exhibited poor aqueous solubility but showed appreciable solubility in non-aqueous solvents. Based on the preformulation studies, a lyophilized parenteral formulation containing 25 mg/mL of Aspirin was prepared in a solvent system containing of 80% v/v water and 20% v/v polyethylene glycol-400 (PEG-400). Rubber closures, filter membranes, and liquid transfer tubing were selected on the basis of compatibility studies. The formulation was subjected to accelerated stability studies. After reconstitution with sterile water for injection, Aspirin injection was stable for a period of 8 hr at 2°C to 8°C. Accelerated stability studies suggested that the lyophilized product should be kept at controlled room temperature for longterm storage. The proposed non-aqueous solvent concentration used, are known to safe hence, toxicities/safety related issues may not raise. The proposed techniques would be economical, convenient and safe. Thus, the study opens the chances of preparing lyophilized formulation of poorly-water soluble drugs.