Voltfast Sachets For Pain Relief contains diclofenac in granular form that relieves pain and reduces inflammation swelling and redness that may occur due to sprains, strains, or other injuries, menstrual pain, migraine attacks, back pain, frozen shoulder, tennis elbow and other forms of soft-tissue rheumatism. It belongs to a family of medicines called non-steroidal anti-inflammatory drugs (NSAIDs). These medicines can relieve the symptoms of pain and inflammation, but they will not cure your condition. It is indicated for short-term treatment for the relief of acute pain and swelling.