USE OF MONOACYL PHOSPHOGLYCERIDES TO ENHANCE THE CORNEAL PENETRATION OF OPHTHALMIC DRUGS

UTILISATION DE MONOACYL PHOSPHOGLYCERIDES POUR FAVORISER LA PENETRATION DE MEDICAMENTS OPHTALMIQUES DANS LA CORNEE

English Abstract

ABSTRACT
The use of monoacyl phosphoglycerides to enhance the
penetration of topically applied ophthalmic drugs through the
corneal epithelium is described.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of enhancing the penetration of an
ophthalmic drug through the cornea, which comprises:
topically applying to the eye an opthalmic
pharmaceutical composition comprising a therapeutically effective
amount of the ophthalmic drug and an amount of a monoacyl
phosphoglyceride effective to enhance corneal penetration of the
drug.
2. The method of claim 1 wherein the monoacyl
phosphoglycerid has the formula:
<IMG>
wherein,
one of R1 and R2 is H or hydroxyl, thiol, amino, alkyl, alkoxy or
alkyl sulfide and the other is an esterified, etherified or
amidified aliphatic hydrocarbon group of 14 to 24 carbons, said
aliphatic hydrocarbon group being substituted or unsubstituted,
with zero to 5 double bonds, and which can be straight chain or
branched, and may be substituted with one or more aromatic,
cycloaliphatic or hydrophilic groups; and
R3 is choline, O-choline, O-(CH2)3-choline, O-glycerol,
O-carnitine, O-inositol or O-lysophosphatidylglycerol.
14

3. The method of claim 1 wherein the monoacyl
phosphoglyceride is selected from the group consisting of:
lysolecithin, lysocardiolipin, lysodesoxylipids, lysophos-
phatidylinositol, lysophosphorylipids and .alpha.-lyso-r-O-alkyl or
O-alkenyl phospholipids.
4. The method of claim 3 wherein the monoacyl
phosphoglyceride comprises lysolecithin.
5. The method of claim 1 wherein the monoacyl
phosphoglyceride concentration is about 0.001% to about 0.5%.
6. The method of claim 5 wherein the concentration is
about 0.01 to 0.1%.
7. The method of claim 1 wherein the composition
further comprises a polymer, protein or polypeptide in an amount
sufficient to provide the composition with a viscosity of up to
about 1000 cps.
8. The method of claim 7 wherein the composition
comprises a polymer selected from the group consisting of
alginates, carrageenan, guar, karaya, locust bean, tragacanth,
xanthan, carbomer, hydroxyethylcellulose, hydroxypropylcellulose,
hydroxypropylmethylcellulose, methylcellulose, polyvinyl alcohol,
polyvinyl pyrrolidone, carboxymethylcellulose and agarose.
9. The method of claim 8 wherein the polymer comprises
hydroxypropylmethylcellulose.
10. The method of claim 9 wherein the monoacyl
phosphoglyceride comprises lysolecithin.

11. The method of claim 10 wherein the lysolecithin
concentration is between about 0.01% and 0.05% and the
hydroxypropylmethylcellulose is present in an amount sufficient
to provide the composition with a viscosity of between about 50
and 300 cps.
12. An improved topical, ophthalmic pharmaceutical
composition comprising:
a therapeutically affective amount of an
ophthalmic drug; and an amount of a monoacyl phosphoglyceride
effective to enhance corneal penetration of the drug.
13. The topical ophthalmic composition of claim 12
wherein the monoacyl phosphoglyceride has the formula:
<IMG>
wherein,
one of R1 and R2 is H or hydroxyl, thiol, amino, alkyl, alkoxy or
alkyl sulfide and the other is an esterified, etherified or
amidified aliphatic hydrocarbon group of 14 to 24 carbons, said
aliphatic hydrocarbon group being substituted or unsubstituted
with zero to 5 double bonds and which can be straight chain or
branched, and may be substituted with one or more aromatic,
cycloaliphatic or hydrophilic groups; and
R3 is choline, O-choline, O-(CH2)3-choline, O-glycerol,
O-carnitine, O-inositol or O-lysophosphatidylglycerol.
16

14. The composition of claim 13 wherein the monoacyl
phosphoglyceride is selected from the group consisting of:
lysolecithin, lysocardiolipin, lysodesoxylipids, lysophos-
phatidylinositol, lysophosphorylipids and .alpha.-lyso-r-O-alkyl or
0-alkenyl phospholipids.
15. The composition of claim 14 wherein the monoacyl
phosphoglyceride comprises lysolecithin.
16. The composition of claim 12 wherein the monoacyl
phosphoglyceride concentration is about 0.001% to about 0.5%.
17. The composition of claim 16 wherein the
concentration is about 0.01% to 0.1%
18. The composition of claim 12 which further comprises
a polymer, protein or polypeptide in an amount sufficient to
provide the composition with a viscosity of up to about 1000 cps.
19. The composition of claim 18 wherein the composition
comprises a polymer selected from the group consisting of:
alginates, carrageenan. guar, karaya, locust bean, tragacanth,
xanthan, carbomer, hydroxyethylcellulose, hydroxypropylcellulose,
hydroxypropylmethylcellulose. methylcellulose, polyvinyl alcohol,
polyvinyl pyrrolidone, carboxymethylcellulose and argarose.
20. The composition of claim 19 wherein the polymer is
hydroxypropylmethylcellulose.
21. The composition of claim 20 wherein the monoacyl
phosphoglyceride comprises lysolacithin.
17

22. The composition of claim 21 wherein the
lysolecithin concentration is between about 0.01% and 0.05% and
the hydroxypropylmethylcellulose is present in an amount
sufficient to provide the composition with A viscosity of between
about 50 and 300 cps.
18

Description

USE OF MONOACYL FHOSPH05LYCERIDES TO ENHANCE
THE CORNEAL PENETR~TION OF OPHTHULMIC DRU~S
The present 1nventlon relates tQ the f1eld of ophthalmlc
drug del1very. More partlc~larly, th1s lnYQntton rel~t~s to
enhancement of th6 penetratlon oP Dphthalm1o drugs and oth~r
th~rapeutlc agents through the cornea of the ~y~.
In order for ~n ophthalmlc drug to be ther~peutic~lly
effectlve, lt 1s gonerally necesssry for the drug to pen~trate
the cornea ~nd bo taken up 1n tho ~queous humor, clllary
processes ~nd othQr tlssues 1n the eye. TherQ are notabl~
excepttons to thls general rule, such ~s drugs or drug products
wh1ch produca a th~r~poutlo effect by act1n~ on th~ ~xter10r
surf~cQ of the corn~a (e.g., drugs or dru~ products usQful ln
improvtng ocular comfort and/or tr~atlng dry or 1rrlt~ted eyes).
HowevQr, th~ tre~tm~nt of cond1tlons lnvolvlng phys1010glcal
mech~ntsms w1th1n tho ~ye (e.g., gl~ucoma, d1abetlc retlnopathy,
cat~r~cts, otc.) g~ner~llY doos requ1re tho movement of topically
appl1ed ophth~lmlc drugs through the cornoa,
In orter for a drug to pass throu~h tne corne~, 1t must
pen~trate threo l-yars of t1ssuQ, n~mely, th~ eplthQllum, stroma
and the ~ndothol1um. Except for h1ghly 11pophll1c drugs, the
eplthel1um ls the m~ln ~rr1~r to drug penetratlon of the cornea.
Pen~trat10n of the stro~a b~1cally lnYolvQs d~ffus10n of the
drug through a barrler wh1ch ls ~pproxlmat~ly 360 m1crons th1ck.
Thero ~re currontly no known.~othods of ~nhanctn~ drug,
penetrAt1on through th~ stro~ or ondothel1um. Howev~r, lt 1s
posslble to enhanc~ th~ p~netr~tlon of dru~s through tha
eplthellum, and theroby enhance the ov3rall absorptlon of drugs
appliet top1cally to the eyo. The prQs~nt 1nventlon 1s dlrectad
to such enhancement.

L-3~
Thero hava b~en prlor ~tt~mpts to enh~nce the
penetrat10n 9f drugs through the corneal ep1thellum, The goal of
such atto~pts h~s gon~rally been to enhance penetr~tlsn of drugs
throu~h the corno~l ep1th21ium to an optt~l po1nt ~t wh1ch the
stroma alona controls drug tr~nsport through the cornea The
prlor attempts have lncludod use of chem1c~1 agents to enh~nce
the penetrat10n of drugs through th~ eplthel1um It has been
reported ~h~t benzalkonium chlorlde (BAC), blte salts, dlmethyl
sulfox1de (DMS0), ethylen~dl~m1ne tetr~acctate (DT~) and 1-
dodecylazayl-cyclohaptan-2 one (A~ONER) enhance the corncal
penetratlon of certa1n dru~s Th~ follow1ng publicatlons may be
referrcd to for further background concernlng the use of such
agents to enhance cornea1 ponetratlon ~ 5~ 9,l~
Vol 53~ p 335 (19~5); ~,_p ~ , Yol 39, p I24 (1987);
Chem Abstracts, Vol 106, 125931t, p 402 (1987); ~Q~rn~l_Qf
Ph~rma~g~cal Sc1~n~, Vol ~7, No l (J~n ,1988); and
, Vol 29, No 2
~Feb ,198B) Notw1thstandlng such prlor attempts, th~ro
contlnues to be a neod for a moans of safely and e~fectlvcly
enhanc1n~ th~ penotratlon o~ drugs through tho corn~a
Su~murv o~ tho,Lny-n~ion
A pr1nc1p~1 obJoct1ve of tho present lnventlon ls to
provlde for a mQthod of ~nhancln~ thc ~b111ty of drugs and
ther~p~ut1c ~g~nts to ponQtr~tQ the cornes A further ob~octlve
of the prQ-ent 1nvent10n 1s to provido top1cal ophthalmlc
composltlons cont~1nlng ons or moro ag~nts for onhanc1ng th~
cornoal ponotr~t10n of the a~t1vo tngr-dlentls) cont~lnod
thcroln
The forogolng obJoctlves and other general obJoctlves of
th~ pr~sent lnventlon are satlsfled by the provlslon of a me4ns
of enhanc~ng corneal ponetrat10n by us1ng ~ class of compounds

~ ~v~
referr~d to hQrQln ~s "mono~cy) phosphoglycer1des~ to enhance the
p~nutr~tlon of ophthal~ic drugs throu~h the corneal op1th~11um
In ~dd1t10n, tha ob~sct1ves of the pr~sQnt lnvsntlon arR
furth~rod when v1scos1ty ~nhanc1ng polymors ~re used 1n
con~unct10n wlth thQ mono~cyl phosphoglycerides to ensur~ the
monoacyl phosphoglycerldes ar~ rcta1n4d 1n th~ oyo for a
rel~t1vsly longer per10d o~ ttm6, thus allow1ng th~ compoun~s
morQ ttme to f~c111tat~ drug transport through tha cornea
~ L~Yr~: I comp~res the amount of a drug, p~ra-am1no-
clontd1ne, found ln the aqueous humor of r~bb1ts wh1ch w~re
admln1stered th~ drug w1th and wlthout lysophosphAtldylchollne
~18 0 ~Lysopc)
Fl~ure Il comp~r~s th~ amount ~f a drug, p~rs-~m1no-
clonld1na, found 1n thQ aqu~ous humor of rabb1ts wh1ch were
admlnistered the drug wtth polyv1nyl ~lcohol ( W A), wlth lysopc
~nd PVA ~nd w1thout elth~r lysopc or PVA
D~t~ g~D~crtp~on or ~bfLll~o~
~ he proscnt lnvent10n ls b-sod on the dlscovery that
amph1pathtc ~ono~cyl phospho~lycerldos offoctlv~ly and safely
enh~nce th~ corn--l pon~trat10n of ophthslm1c drugs These
pen~tr~t10n onh~ncor~ c~n be usod ln compos1ttons compr1slng ~ny
ophth~lm1c ~rug ~hlch, to bc cff~ctlvo, must be subst~nt1ally
t~ken up by thc ~uoous humçr, clllsry processes snd oth~r
tlssuQs 1n tho ~yc upon top~csl ~dm1n1str~t10n Exsmplos of
cl~sses of ophth-lmlc drugs wlth ~hlch th~ mono~cyl
phosphoglycor1des of thQ pr~s~nt 1nvcnt10n c~n ba uscd, lnclude
sterolds, growth f~ctors, cycloplog1ts, m10t1cs, mydr/at1cs,
thorap~ut1c prot~lns and pdpt1des, ant1cx1d~nts, ldose roductas~

'rD '1,) r
lnh~bltors, nonsteroldal ~ntlln~lammatorles, 1mmuomodulatQrs,
ant1all~r~1cs, ant1m1croblals ~nd anti-gl~ucoma ag~nts.
~ he p~netr~t10n enhanc1ng mono~oyl phospho~lycer1des
us~d ln thc present tnvent10n h~ve the follow~ng stru~tur~:
~ ,0'
0~ ~
R3
wher~1n one of Rl and R2 1s hydrogen, thlol, hydroxyl, amlno,
lower ~lky1, lo~er alkoxy (~S methyl, ethyl, methoxy or ethoxy)
or alkyl sulflde And the other ls an esterlfled, etherlf1~d or
amldtfl~d hydroph~btc group, and R3 ls a hydrophll1c group. The
pref~rred hydrophoblc sroups lnclude saturatsd ~nt unsaturatod
allphatlc hydroc~rbon groups whlch rang~ from 14 to 24 carbons in
length w1th zero to 5 doubl~ bonds. The allphat1c hydrocarbon
gro~ps c~n be str~1ght or br~nchQd chaln and msy be substltutQd
by one or mor~ aromat1c, cycloallph~tlc or hydrophilic (9.9.
hydroxyl, thlol, or am1no) groups. Examplos of sult~le hydro-
ph111c groups (~3) 1nclude O-inosltol, chollne, O~cholinQ,
O-c~rnlt1nel 0-(CH2)3-choltne. O-g~yc~rol and O-lysophosphatldyl-
glyc~rol.
Tho prbferr~d mono~cyl phosphoglycer1dos are
lysophospholtplds, such as lysophosph~tidylchollnQ, lysophos-
phattdyl1nos1tol, (lysolcclthln). lysocardiollpln,
lysodcsoxylip1ds, lysophosphoryllplds ~nd oC~lyso-r O-alkyl or o-
alkenyl phosphol1plds such ~s DL~o~-Lysolec1thln-r-0-hox~decyt
and DL-cC-Lysoloc1th1n-r-O-alkyl. The ~ost prcfcrrod mono~cyl
phosphoglyc~r1dQ 1s l-acyl lysophosph~tldylchol1na (Cl8:0, ClB:l,

C16:0 or Cl6:l). The l-acyl lysophosphat1dylsholine C18:0
(lyso~elth1n) wht~h ls most preferr~d h~s the follow1ng
structur~l fonmul~:
~ C~H~
/ ~ O~
L~
The monoaeyl phosphoglycer1d~s whlch ~re useful 1n the
pr~sent lnventlon may b~ descr1bed as be1ng ~mphlpathtc~, stnce
they 1ncludo both hydrophlllc ~nd hydrophoblc groups. ~h11e not
w1sh~ng to b~ bound by ony theory, 1t Is bellQved th~t
~mphlp~th1c monoacyl phosphoglycer1des onhance the corn~al
p~netrat10n of drugs by partltlon and lntorsctlon wlth protein,
glycoprotoln and llpld components pr~sent ln th~ membr~ne of the
cornQsl eplthel1um. Such lnter~ct10n ts bel1eved to ~ltsr the
t~gree of orter of th~ protelns and llpids ln the ~mbrane,
theroby modlfy1ng the functlon of th~ op1thellum as a barr1er to
drug pcnetr~tton. ~h~tov0r the moch~n1sm, th~ net result 1s ~hat
dru~ ponatr~t10n of th~ ep1th~11u~ ls enhancod.
_ .
The use of mono~cyl- phosphoglyeerld~ in ~ccord~nce wlth
the pros~nt ~nventlon to cnhAncc cornoal p~natr~tlon of drugs
s1gnlflcsntly lncre~s~s thQ ~mount o~ dru~ ~hlch 1s sblo tc
pon~trato the cornoa. Th~ dogree of ~nhanc~Fent wlll vtry wlth
dlfforQnt druos, but ln som~ CaSQS may be ~5 much as 3-fold or

f '~ J
more. Bec~u~ drugs con mors effectlvQly p~netrat~ the corn~,
less drug ls 105t due to flow down the punctum and th~refore less
drug n~ed b~ admlnlst~red to eff~etlvely tr~at a par~1cu1~r
1ndicatlon. Thls ls p~rt1cu~arly b~neflclal when 1t ls necesstry
to adminlstcr drugs whlch c~us~ severe systemlc slde effects.
The amount of monoacyl phosphogtycer1dQ requlred in
order to enh2nco corneal penetrat10n w111 depend on v~r10us
factors, suCh ~s thc solublttty, part~tlon csefflc1ent ~nd
molecular wRtght of th~ ophth~lmic druq or therapeutlc a~nt; ~he
excip10nts (surf~ct~nts, pr~s~rvat1ves, polymers) presQnt ln the
formul~tton; ~nd the part1cular mono~eyl phospho~lyccr1de be1ng
used. In gener~l, the mor0 11poph11ic the drug to be del1vered,
thQ less ~cnoacyl phosphoglyc~rlde 1s requ1red to enhanc~
pQnetr~tlon~ and the h19her the concentration of monoaeyl
phosphoylycerlde, thQ better the corneal pen~trat10n. Typically,
one or ~orc monoacyl ph~spho~lyc~rldes wlll b~ used 1n 2n ~mount
ef from ~bout O.OOlX to about O.5X (wet~ht/volumQ) prefar~bly
from about 0.01 to 0.1%.
The mono~cyl phospho~lycer1~es can b~ used 1n any
top1cal dru~ dellvery system ~her~1n ~n exclptent or v~hlcle wlll
not substantlally 1mp~1r or pr~vant the monoacyl
phosphoylyc~r1d~s fro~ functtontn~ as corn~al pen~tr~tlon
enhano~rs. For examp~o, th~ mono~cyl phosphoglycQrtdes can be
formulatod 1n composlt10ns which are solutlons, suspon~tons,
o1ntments, g~ls or ftlms. ~he tYp~ of composlt10n wlll dopend
on, among oth~r thlngs. the eh~mlcal and physlca1 prop~rtl~s of
thfl drug or therapeutlc ~nt--to be dellvered. ~heso propQrt~os
are well knom to a person of ord1nary sklll 1n the ~rt of drug
formulat10n and dellvQry.
In ~ preforrod 6mbodlm~nt, thQ pr~sent lnventlon further
comprlses the US9 0~ polymers ln tonJunctlon wtth the monoacyl

phosphoglycQrld~s to ~nh~nc~ ocul~r blo~v~llab111ty. The lon~er
a top1c~1 ophthalmtc formul~t~on ls 1n cont4ct wlth th~ ~ye the
better the ocul~r bio~vallablllty. Through the us~ of po7ymers
1n conjunction wlth th~ abov~ descr~bed monoacyl phospho-
glycer1des th~ compos1t~ons of the presont 1nv~nt10n ~re retained
on the corn~a longQr. As a result, the penetrdtlon ~nhanctng
components of the composlt10ns cbn more effectlvQly 1nteract w1th
the corn~al eplthel1um to enhance p~natrat10n of tho d~s1r~d
drugs or th~r~p~ut1c agents lnto thQ ~ye. It has b~en found that
the usc of polym~rs 1n conjunctlon wlth monoacyl
phosphoglyc~rld~s can provlde for up to ~bout a 9 to lO fold
lncr~se ln th~ ~ount of drug or thcrapeut1c a~ent made
av~lla~le to th~ ~ye. The ef~ectlv~n~ss of th~ mono~cyl
phospho~lycer1des Is lmproved when the vlscos1$y of the
co~pos1t10ns cont~1n~ng the mono~cyl phospho~lycer1des 1s
1ncr~ased up to ~bout I000 c~ntlpolse (cps), pref~rab1y bstween
~bout 50 cps. to 30G cps. Polym6rs aro ~dded to provlde for thls
dos1red Ytscos1ty 1ncro~ss.
Any synth~tlc or n~tural poly~er whlch ~lll 1ncrease
vlscoslty and ls compattble wlth tlssu~s of the ey~ and the
lngredtQnts of the monoacyl phosphoglycer1de composlttons.can be
used. Such polym4rs are refcrr~d to hcro1n as ~vlscoslty
onhancln~, ophth~lm1c~11y ~ccept~blo polym~rs.~ Exampl~s
1ncludc, but ~rs not 11~1tod to: natur~l polyt~ccharldes and
gums, such ~s: ~lgln~tes, carrag~on~n, guar, kar~ya, locust bean,
tragac~nth ~nd x~nth~n; ~nd synthotlc polymers, such ~s:
carbum~r, hydroxyethylcellul OSQ ~HEC), hydroxypropylc~llulose,
hydroxypropylmothylcellulosa-~HPMC), mQthylc~llulosQ, polyvlny1
alcohol (P~IA), polyv1nyl pyrrolldon~ carboxymothylcollulos~ and
agaros~. In ~ddltion protelns ~nd synthotlc polypeptldcs wh1ch
enhance vlscos1ty Jnd aro ophthalm1cally 4cceptab1~ c~n b~ used
to 1ncroase tho v1scos1ty of tho compos1t10ns to prov1de for

better b10~ billty. ~yplcally, protelns wh1ch c~n b~ used
include: gQlatln, coll~gen, album1n and c~sQln.
~ hR preferred v1scos1ty enhanclng a~ents ~re one or more
polymers select~d frDm: PVA, HPMC ~nd ~EC. Th~ most prefarrod
agQnt 1s HPMC. The v1scos1ty ~nhanc1ng ~g~nts are ~dded to
provlde for composlt10ns w1th a v1scoslty of betwQen about S0 and
300 cps.
~ hQ preferr~d m4thod for enh~ncing the pen~tratlon of a
drug or therap~utlc agent compr1sQs the use of lysophosphat1dyl-
chol~ne (C18:0~ ~t a concentrat10n of about O.OlX to 0.05X ln
comb1nat10n ~lth the polymÆr HPMC tn an amount suFflclent to
prov1de a composltion wlth a vlscos1ty of bout S0 to about 300
cps ~
The followtng ~x~mples furth~r lllustr~t~ the
compos1ttons whlch, ~ccordtn~ to the prcsont lnvcntlon, comprlse
monoac~l phospho~lrccrides, the cornaal pcnotrat10n enhanclng
propertlos of the monoacyl phosphoglycerld~s and the1r USQ to
enhance corneal pcnetr~t10n.
~L~
~ h~ following formulatlon is n ex~mpl~ of a top1cal
ophth~lmlc composlt10n whlGh can be USQ~ to tre~t glaucoma.

;3
~,,~
InarQdl~nts _ ~(we~gh~yol~L
P~ra-amlno~elon1dlne 0.293
Hydroxypropylmethyloellulose-E50L~,(HPMC)USP 3.3
Lysophosphat1dylcholine ~Cl8:0) ~.03
B~nzalkon1um chlorld~ 0.0l
Dlsodlum Edatate, USP ~.01
Sodlum phosph~te, monobas1c, USP 0.18
Sodlum phosphat~, d1bas1c, USP 0.12
M~nnltol, USP 3.3
~C1, NF ~nd~or NaOH, NF q.s. ph to 6.5+0.2
Purlf1~d ~ater, USP q.s. IOO
_
~Equiv~lent to Q.2SX + 2X excess para-am1no-clonldlne as fre~
base.
Prep~a~iQn
~ he formul~tlon 1s prep~red ln two parts. The
hydroxypropylmethy k ~llulose 1s f1rst d1ssolvQd ln purlflod water
to m~ke ~n ~pprox1~-tely IOX solut10n. Thls solutton ls then
cl~rlfled by f~ltr~tlon and st~rlllzed by autoclav1ng.
The othQr lngr~d1ents re n~xt dlssolved ln
approxlm~t~ly one-half of the purlfled wat~r. ~ho mlxturo ls
warmed to 40 ~ 6C for appro~lmatQly 30 mlnutos to omplete
dlssolutlon of th~ lysophosphatldylchollne. The pH of the
solutlon ls adJust~d to 6.S ~nd the solut10n ls sterlllzed by
sterlle f11tratlon.

Th~ t~o solutions Yre mtxed ~sept1cally, stirr~d, and
th~ r~1n1n~ purlft~d w~t#r ls u~ed to bring the solutton to
flnal volum4.
EXAMPL~ 2
FOr~ua~$1on
~~ ~
Potasslum chlorlde 0.02
Monobaslc potassium phosphate 0.02
Sodlum chlorlde 0.80
D1bas1c sodlum phosph~te 0~2l6
Lysophosphat1dylchol1n~ C18:0 (Lysopc) 0.03
Pdr~-am1no-clonld1n~ 0.25
W~ter q.s. to lOQ%
. . ~
Proc~du~ Prap~ratlQ~ Qf ~ormula~lon
Approx1m~tely 85X (8.5 ~1) of the batch ~olu~e of
purlf1Qd wator w~s add~d to ~ cont-lner. All of th~ tngredlents
were th~n ~ddsd to th~ contalner: 0.002g pot~sslum chlorld6;
0.0809 sod1um chlor1d~; 0.0021~ monobaslc potass1um phosphato;
O.Q216g d1b~slc sod1um ~hosphat0; 0.25~ p3ra~umlnoclontd1ne. The
1ngr~diQnts wQre m1xed w~ll. 0.003g lysopc was addod to the
conta1n~r and sonn1catod wlth he~t (30C) for 30 mlnu hs. Th~ pH
was 2dJust~d to pH 6.0 ~1th lH HCl (0.20 ~1). Th~ solutlon WAS
th2n f11t~red through ~ st~rll121n~ fllter lnto ~ st~rlla
roee1v1ng ves~sl. Pur1fl~d water (q.s. to 10 ml) was th~n pourQd
throu~h th~ st~rlllzlng f11ter and tho solutlon was mlxsd w311.

h.~X ~2~
Tw~lve New ~e21~nd albino r~bblts w~rQ sQ)ecte~ for
ev~luat10n o~ thQ pQn2tr~tlon throu~h the corn~a of ths p~ra-
amlno-clonld1ne formulat10n sst forth Above. All rabb1ts
rec01vad 30 ul of the 0.25% para-am~no-c70nldtne top1c~11y in
both ey~s. Four rabbtts wer~ sacrlf1ced ~t 20 mlnutes from
dosing ~nd aqu~ous humor was wlthdr~wn from th~1r oy~s. The
aqueous humor w~s ~ssaysd by 11qu~d sc1ntlllat10n count1ng to
det~r~1no tho mount of par~-~mtno-clon1dlne ln ths ~qu~ous
humor. The s~me procedur~ was done on ~ dlfferent rabb1ts at C0
mlnutes from dos1ng ~nd on ~nother 4 r~bb1ts, l20 mtnutes from
dos1ng. Twtlve control r~bblts reco1ved 0.25X par~-am1no-
clonld1ne as set forth 1n the formulatlon above wlthout 0.03%
lysopc. Aqucous humor W2S wlthdrawn and assayad ~s ~xplalnQd
abovc. The results are shown 1n the gr~ph dQplct~d ln F1gure I.
It can be seon from th~ gr~ph that the ~mount of p~r~-amlno-
clon1d1ne 1n tha aqU00~5 humsr ls gr~ter tn the r~bblts treated
wlth tho formulat10n contaln1nq 1YSDPC~ At 6~ mlnutes there 1s
almost ~ four fold lncreas~ tn the ~mount of par~-~mlno clonldtne
found 1n the aqueous humor of those rabblts wh1ch rec~ived the
drug 1n con~unctton wlth lysopc versus thoso who rece1vod the
drug ~lthout lysopc. ThereforQ, thQ rcsults lndkAte that lysopc
enhanced pRnetrat10n of p~ra-am1no-clonldtne through the cornea.
ID9L3~19D~ Co~n~ on X~w/v)
Monobastc potasslum phosph~te 0.067
D1baslc potass~um phosphat0 3.137
M~nnltol 2.~5
PVA 7~0
Lysophosphatldylcholine Cl8:0 (Lysopc) C.03
Par~-amlno-clonidlne 0,50
~t~r q.s. to ~oo%
11

Approximately B5% (8 5mt~ of the batth volume of
purlf1ed water was add~d to a cont~lner A11 of the lngr~dlents
w~re added to the conta1ner O OOt7g monob~s1c potasslum
phosph~te; 0 013~g d1b~slc potasslum phosphate; 0 2~5~ mann~tol;
0 7g P~A; 0 05g p~r~-~m1no-clonld1ne The 1ngredients w~re mlxed
well ~nd st1rrfld unt11 ~ll 1ngr~d1ants d1ssolved lnto ~ solutlon
0 0039 lysopc w~s ~dded to thc cont~1ner ~nd sonnic~t~d ~lth heat
(30C) for ~0 mlnutes Tho pH was adJusted to pH 6 5 wlth NaOH
Purlfl~d w~ter (q s to lOml) w~s th~n poured through a
sterll1zln~ filter ~nd the solutlon w~s m1xed well
Twelv~ New ~oaland ~lbtno r~bbtts were solected for
evaluat10n of tho p~nctr~t10n through the cornQa of the para-
~m1no-clon1dlne for~ulat10n set forth a~ove All rabblts
recelved 30 ~1 of the 0.50X para-am1no-clonld1ne top1cally ln
both eyes Four rabb1ts wore s~crlf1ced ~t 20 mlnutes from
dos1ng ~nd th~lr ~qu~ous humor w~s w1thdr~wn from tholr OyQS. The
aquoous humor w~s ~ss~yQd by liqu1d sclnt~llat10n count1ng to
d~terminc the ~mount of para ~m1no-clon1dlns ln thQ ~queou~
humor Th~ s~n4 proccdure w~s dono on four d1fferont rabb1ts at
60 mlnutos from dos1ng and on ~nother four rabblts, 120 minutes
from doslng Tw~lve control rabb1ts rece1v~d 0 50X p~ra~amlno-
clonldlno s SQt forth in the formulatlon abov~ wlthoùt 0 03X
lysopc ~nd ~.CX PVA Another 12 rabblts rocetved 0 50~ para-
~m1no~clon1d1no as s~t forth 1n tho formulat10n abov~ w1thout
0 03X l~sopc Aquoous humor w~s wlthdrawn ~nd ~ss~yod ~s
oxplalnod above Tho rosults are shown ln th~ or~ph dsp1ct~d ln
Flguro II It c~n bo so~n from the 9r-ph that tho amount of
par~amlno~clonld1no ln tho ~queous humor ts gro-t~r ln the
rabb~ts tr~ted wlth th~ ~ormul~tlon c~ntaln1n~ PVA ~nd PVA wlth
lysopc At 60 mtnutes thore 1s almost a 2 5 fold and lO fold
1ncr~ase ln th~ ~mount of pAra-~m1no~clonldlne found ln the

r~
~queous humor of those r~bbtts ~hlch rece1v~d th~ drug 1n
con~unctlon ~lth PVA or wlth PYA and lysopc, rospect1~ely, v~rsus
thos~ whlch recelY~d thQ drug without PVA or PYA ~nd lysopc. The
results 1nd1cate that lysopc h~s enhancod penetrat10n of para-
am1no~clon1dlno throu~h the corne~ over PYA alon~ snd p~ra-~m1no-
clonldlne ~lone.

Representative Drawing