exec procedure Tuning

[najjar2000]

hi i wrote this package when execute package take more than 30 sc
how can incress speed exec sp
the code as the follwing
procedure ret_formal(V_ECNMY_EQTN_ID_FRMLA in number
,Company_id1# in number
,v_external_parm1 in varchar2 default null
,X_AMMOUNT1 out varchar2) is

X_AMMOUNT VARCHAR2(4000);
VAR VARCHAR2(1000);
EQUATION VARCHAR2(4000);
F_EQUATION VARCHAR2(4000);
x_function VARCHAR2(4000);
x_func_res varchar2(2000);
main_id# number;
ycat_id# number;
prd_id# number;
stat_flg number;
stat_flg_char varchar2(30);
sum_fhp varchar2(100);
prmt_no number :=0;
xloop number:=0;
PKG_FUN varchar2(200);
xparameter1 varchar2(1000);
xparameter2 varchar2(4000);
xparameter3 varchar2(200);
string# varchar2(4000);
YEARS VARCHAR2(30);
code_char VARCHAR2(250);
desc_val varchar2(250);
desc_val1 varchar2(250);
uq_variable_prd varchar2(4000);
uq_variable_cat varchar2(4000);
uq_variable_flg number;
add_where varchar2(4000);
l_srl# number;
curr_srl# number;
var_value# varchar2(100);
TYPE MYDATA IS REF CURSOR ;
retdata MYDATA;
vcat_id# number; -- for loop --> DTL-CODE
vprd_id# number;-- for loop --> DTL-CODE
add_where# varchar2(100);
indicator_id number(10);
begin

FOR REC IN (SELECT SST_ECNMY_EQTN_SER SER#
,SST_ECNMY_EQTN_VAL VAL#
,SST_ECNMY_EQTN_TYP TYP#
, STATS_COD_ID FUNC#
, ECNMY_EQTN_ID
, ECNMY_EQTN_ID_FRMLA FRMLA#
,main_cod_id
FROM SST_ECNMY_EQTN
WHERE MAIN_COD_ID = (SELECT MAIN_COD_ID
FROM SST_ECNMY_EQTN
WHERE ECNMY_EQTN_ID = V_ECNMY_EQTN_ID_FRMLA
)
AND SST_ECNMY_EQTN_SER != 0
ORDER BY SER#
) LOOP

[PAVB]

Please post code wrapped into CODE tags, also describe tables and available indexes including cardinality. Please post execution plan as well.