SQL> create or replace package plch_pkg
  2  as
  3    subtype TRow is user_users%rowtype;
  4  end plch_pkg;
  5  /

Package created.

SQL> declare
  2    r plch_pkg.TRow;
  3  begin
  4    select * into r from user_users;
  5    execute immediate 'declare r plch_pkg.TRow := :1; begin dbms_output.put_line(r.username); end;' using r;
  6  end;
  7  /
ELIC

PL/SQL procedure successfully completed.

SQL> drop package plch_pkg;

Package dropped.

Disconnected from Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options