SQL & PL/SQL

I have proc as below.

Input value will be in the format 123,9092

but even though database has value,the proc returns null

please help

PROCEDURE GET_HIP_MED_CENTER_DESCR (p_in_provnum in varchar2 ,p_out_HIP_MED_CENTER OUT ref_cursor)is
   p_provnum varchar2(100);
         BEGIN
         
SELECT '''' || REPLACE(p_in_provnum,',',''',''') || '''' into p_provnum FROM DUAL;
         
         dbms_output.put_line(p_provnum);
         
  
 
         OPEN p_out_HIP_MED_CENTER FOR
          SELECT distinct PROVNUM,MED_CENTER
           FROM hip.ref_hip_med_centers 
           where  PROVNUM IN (p_provnum) AND MED_CENTER_DIPLAY is not null 
           order by MED_CENTER asc;
       
     end;