Once again, the FDA has issued a Warning Letter to an Indian API manufacturer. The state of the manufacturing equipment and the missing validation of a tableting process for a vasodilative drug were the main points of criticism. The FDA inspection already took place in September, 2016. The response of the Indian manufacturer was insufficient and led to a Warning Letter. During the inspection, the FDA had witnessed several parts of the equipment (for tablet production) with holes, rust on the inner and outer surfaces and equipment with missing parts. It is interesting to note that even before the inspection, there were complaints in the U.S. because of metal pieces in tablets. In his investigation, the Indian manufacturer did not associate this with the deficient condition of his production equipment though. Up to now, the FDA has not received a retrospective evaluation by the manufacturer regarding which pieces of equipment are/were defective and which batches had been shipped to the U.S. This has once more been demanded in the Warning Letter.
Furthermore, it was noted that there was no validation for isoxsuprine hydrochloride tablets although they were delivered to the U.S. The manufacturer had stated in his response to the inspection report that he did not produce this kind of tablets currently...
The FDA also states that the isoxsuprine hydrochloride tablets produced appear to be identical to Vasodilan tablets. Their approval for the U.S. had already been withdrawn in 2009 and they are currently being re-examined as part of a Drug Efficacy Study Implementation (DESI). The manufacturer had neither sufficiently indicated this on the label nor warned of potential risks related to ingestion. What's more, not all excipients used are listed on the label, which has been classified as misbranding by the FDA.
On the FDA website you can find the original Warning Letter to Vista Pharmaceuticals Limited.