Circular No. 72/46/2018-GST dated 26th October 2018 
Procedure in respect of return of time expired drugs or medicines-Clarification by CBIC-Circular No. 72/46/2018-GST dated 26th October 2018:
Goods may be returned in either of the one way:
Return of goods may be treated as a fresh supply and invoice can be issued for the same. The value of the said goods as shown in the invoice on the basis of which the goods were supplied earlier may be taken as the value of such return supply. The wholesaler or manufacturer, as the case may be, who is the recipient of such return supply, shall be eligible to avail Input Tax Credit (hereinafter referred to as “ITC”) of the tax levied on the said return supply subject to the fulfilment of the conditions specified in Section 16 of the CGST Act.
The retailer or wholesaler may return the time expired goods by issuing a credit note and delivery challan. It may be noted that there is no time limit for the issuance of a credit note in the law except with regard to the adjustment of the tax liability in case of the credit notes issued prior to the month of September following the end of the financial year and those issued after it.
In case time expired goods are returned beyond the time period specified in the sub-section (2) of section 34 of the CGST Act and a credit note is issued consequently, there is no requirement to declare such credit note on the common portal by the supplier (i.e. by the person who has issued the credit note) as tax liability cannot be adjusted in this case.
Refer : Circular No. 72/46/2018-GST dated 26th October 2018