Engineering, 2012, 5, 27-29
doi:10.4236/eng.2012.410B007 Published Online October 2012 (http://www.SciRP.org/journal/eng)
Efficacy and Safety of Nasal Administration of “Na-
no-L-DOPA” Based on PLGA Nanoparticles
I. G. Kondr asheva1, T. A. Antipova1, G. G. Barsegyan1, P. Ye. Gambaryan2, A. A. Guseva2, A. A. Kamensky2
1Research Center of Molecular Diagnostics & Therapy, Moscow, Russia
2Moscow State University, Moscow, Russia
Received 2012
ABSTRACT
Inclusion of L-DOPA , th e standard Parkinson’s disease medication, into polymeric particles (PLGA) results in optimization the drug
metabol ism and increas ing its bioavailability, significantly increases of physical endurance, better coordination and lower anxiety in
Wistar rats, when chronical ly administ er ed nasal ly.
Keywords: Nanopaticls; L-DOPA; Nasal Administration; Parki nson’s Disease
1. Introduction
Nasal administration of medications is a well known and cur-
rently widely applicable method of administration of a number
of broad-spectrum drugs, both locally and systemically acting,
the interest in which, as a non-invasive method of administra-
tion drugs, deepens on [1]. Due to vascular plexuses in nasal
cavity and a large absorption area, nasal administration of me-
dications becomes a prospective method of delivering drugs
directly into the blood stream, promoting fast achievement of
the effective drug level in blood. Additional benefits of nasal
administration are ease of performing, usability for patients,
and a relatively low cost. Moreover, drugs can be transported
from nasal cavity into the central nervous system (CNS) with-
out involving the blood circulatory system of nasal-cavity lin-
ing mucosa, b y extra cell ul ar way – alon g th e tri facial ner ve an d
the olfactory nerve. Olfactory nerve sheathes do not have
blood-brain barriers, and the drug can directly enter the brain
[2-5]. This fact is the focus of attention, since it provides new
opportunities in treating CNS diseases, particularly neurodege-
nerative brain diseases, such as Parkinson’s disease or Alzhei-
mer’s disease [6]. The “nose-brain” way leads to practically
immediate delivery of some drugs into the cerebrospinal fluid,
bypassing blood and the blood-brain barrier (BBB) [7-10].
L-3,4-dihydroxyphenylalanine (L-DOPA) is the precursor of
dopamine that is responsible for the central mechanism of mo-
tion control and coordination. Applying L-DOPA in the treat-
ment of Parkinson’s disease has a number of disadvantages.
Optimizing the drug metabolism and increasing its bioavaila-
bility and potency are possible, if it is included into nanopar-
ticles based on poly(lactic-co-glycolic acid) (PLGA), a biode-
gradable and non-toxic polymer. Including a drug into the par-
ticles allows modulating the biopharmaceutical properties of
the medications administered, their bioavailability and, as a
consequence, their potency [11]. Moreover, nanocontainers
protect the drug components against chemical/enzymatic de-
gradation, provide durable release, decrease the drug toxicity
for peripheral organs, and represent drug containers suitable for
treating the CNS diseases [12].
The purpose of this research is the estimation of efficacy
and safety of the nasal administration of L-DOPA, the precur-
sor of the dopamine neurotransmitter, in form of a nanoparticle
medication (“Nano-L-DOPA”) developed on the basis of
poly(lactic-co-glycolic acid) (PLGA) for modulating (increas-
ing) the exercise performance o f rats Wistar, as compared to the
efficacy and safet y of L-DOPA, the initial standard medication.
2. Materials and Methods
In this paper, L-DOPA (Sigma, China), 1 mg/kg, and “Nano-L-
DOPA” (Resear ch Cen ter of Molecul ar Diagn o stics & Th erapy,
Russia), 1 mg/kg, 5 and 10 mg/kg (by L-DOPA), were re-
searched. Particle sizes of the latter one varied from 250
through 400 nm, while the L-DOPA substance content within
the “Nano-L-DOPA” composition ranged from 9.5 through
12.0% of the mass. The research in the dynamics of the drug
release from the nanocomposition in a model experiment in
vitro testifies that up to 70% of L-DOPA contained in the par-
ticles are released within the first 30 minutes, while the resting
30% o f the active substance are r eleased withi n the subsequent
10 hours. The solutions of L-DOPA were prepared i mmediately
prior to the start of the experiment. Normal saline solution was
used as a dissolution medium, ascorbic acid (1%, pH 2.6) being
added for bettering the dissolubility and preventing the drug
from oxidation on dissolving. Animals in the Baseline were
administered with blank particles in the amount corresponding
with the maximum dose of the nano-medicatio n. In the resear ch,
male Wistar rats weighing 200-250 g and BALB/c mice (20 g)
were used.
The drug influence upon the exercise performance, the mo-
tion activity and the behavior of the laboratory animals in the
long-term experiment was researched comprehensively using a
number of tests.
1) In the dynamic load conditions, in test “Forced Swim-
ming” up to complete fatigue with weights (15% of their body
masses), the drug influence upon the exercise performance of

I. G. KONDRASHEVA ET AL.
28
the rod ents was estimated fo r the mixed-nature loads (the limits
of anaerobic and aerobic power). Th e animals were placed in to
water-containing tanks where the duration of their active and
passive s wimming was register ed. The fatigu e criterio n was th e
animal’s sinking to the tank bottom, upon which it did not rise
within 10 seconds. The drug potency criterion was a positive
increase of the total exercise performance time in 30 minutes
upon the drug administration, as compared to the baseline value
of the experimental group at the start of the experiment and the
control group. The tests were performed on the 1st, 8th, 15th и
22nd day upon the drug administration, and in five days upon
the discontinuation of drug administration (on the 27th day), in
order to detect th e delayed effects of th e drugs.
2) For simulating the static physical load, the test of “holding
on a vertical grid” was used. The drug potency criterion was a
positive increase of the total test performance time (upon five
representatio ns) in the stati c exercise performance co nd itions in
30 minutes after the nasal administration of the nanodrug, as
compared to the control group and to the reference compound
of L-DOP A with a similar targeted action.
3) Researching the vestibulo-locomotor activity on the Ro-
taRod device is based on the animal’s capab il ity to bal ance on a
rotating cylinder (rod), while the speed of the rod is slowly but
continuously accelerated (the initial rod rotation speed was 0.4
rpm, acceleration was 0.4 rpm/s). During the experiment, the
time was registered, within which the rats managed to stay on
the RotaRod (Columbus Instrument, USA). The procedure was
repeated three times. Test was conducted in 30 minutes upon
drug administration.
4) The behavior of rats in the “open field” test was re-
searched in order to estimate possible consequences of chronic
administration of Nano-L-DOPA for the motor and exploratory
activity of unrestricted experimental animals within 5 minutes.
A special attention was paid to the following parameters: hori-
zontal and vertical activity, number of visits to the center of the
“open field”, as well as the number of grooming acts.
The statistical analysis of results obtained was performed
using Microsoft Excel 2010 and STATISTICA 8.0.
3. Results
1) Chronic nasal administration of the minimum dose under
research (1mg/kg) of “Nano-L-DOPA” into rats was proved to
be positively more effi cient on all test ing days, as co mpared to
the same dose of L-DOPA (p < 0.01), and resulted in the posi-
tive increase of the animals’ endurance upon 2-week adminis-
tration (p < 0.01), the effect being retained upon discontinua-
tion of the drug within 5 days, u nlike L-DOP A, the comparato r
drug (Figure 1).
The maxi mum effect was detecte d on the 15th day of the ex-
periment at administering “Nano-L-DOPA” dosed as 1 mg/kg
and 10 mg/kg, and on the 22nd day of administering it in the
dose of 5 mg/kg. In 5 days upon discontinuation, a positive
retention of the high endurance level at the minimum doses
under research, 1 mg/kg and 5 mg/kg, was observed (Figure 2).
Important note: Using “Nano-L-DOPA” in all doses under re-
search (1 mg/kg, 5 mg/kg and 10 mg/kg) does not result in
performance decrement within at least five days after the drug
administration has been discontinued. The dose of 5 mg/kg (by
L-DOPA) can be considered the optimal dose of “Nano-L-
DOPA” resulting in a stable, statistically valid increase in the
physical endurance of dynamically loaded rats on all testing
days, starting from the 15th day of the experiment, at nasal ad-
ministration.
2) In the conditions of a static physical load (test “holding on
a vertical grid”) the chronic nasal administration of Nano-
L-DOPA had resulted in the positive increase of the total time
of the rats’ holding on the grid as compared to the control group
and to the comparator by the 16th day of administering “Nano-
L-DOPA”. The dose-dependent effect of using the nanodrug
was observed, the doses of 5 and 10 mg/kg being most efficient
(p<0.03 and p<0.01, respectively). In five days upon the dis-
continuation of the drugs, the positive differences only retained
in the group of animals administered with the nanodrug dosed
as 5 mg/kg (p<0.2). Using L-DOPA, the comparator drug, re-
sulted in no increase in the endurance within this experiment
both during the drug administration and upon its discontinua-
tion.
Day1 Day8 Day15 Day22 Effect
Control L-DOPA,1 mg/kg Nano-L-DOPA,1mg/kg
170
150
130
110
90
70
50
%
*p<0,05
Day1 Day8 Day15 Day22 Effect
Control L-DOPA,1 mg/kg Nano-L-DOPA,1mg/kg
170
150
130
110
90
70
50
%
170
150
130
110
90
70
50
%
*p<0,05
Day27
Day1 Day8 Day15 Day22 Effect
Control L-DOPA,1 mg/kg Nano-L-DOPA,1mg/kg
170
150
130
110
90
70
50
%
*p<0,05
Day1 Day8 Day15 Day22 Effect
Control L-DOPA,1 mg/kg Nano-L-DOPA,1mg/kg
170
150
130
110
90
70
50
%
170
150
130
110
90
70
50
%
*p<0,05
Day27
Figure1. Efficacy of “Nano-L-DOPA” as compared to “L-DOPA”
at chronic nasal administration of 1 mg/kg in the test “forced
swimming” with weights.
170
150
130
110
90
70
50
%
Day1
Day8
Day15
Day22
Effect
Control Nano-L-DOPA,1 mg/kg
Nano-L-DOPA, 5 mg/kg Nano-L-DOPA, 10 mg/kg
*p<0,05
Day27
170
150
130
110
90
70
50
%
Day1
Day8
Day15
Day22
Effect
Control Nano-L-DOPA,1 mg/kg
Nano-L-DOPA, 5 mg/kg Nano-L-DOPA, 10 mg/kg
*p<0,05
Day27
Figure 2. “Nano-L-DOPA” efficacy comparison for different doses
at chronic nasal administration in the test “forced swimming” with
weig h ts.

I. G. KONDRASHEVA ET AL.
29
3) The research in the vestib ulo-locomotor activity of Wistar
rats using RotaRod in the conditions of chronic nasal adminis-
tration of “L-DOPA” compounds within 20 days, in the minim-
al daily doses of 1, 5 or 10 mg/kg, did not show any distur-
bances in locomotor activity or any spatial disorientation in the
animals. Administering “Nano-L-DOPA” in all doses under
research promoted the positive improvement of the animals’
rotarod performance and sp atial orientation ability.
The largest values o f RotaRod p erformance had reached sta-
tistically valid differences in all group s of animals admin istered
with the nanodrug, as compared to the control group (p>0.1)
and to the group administered with standard medication
L-DOPA (p>0.2), by the end of the experiment (the 20th day o f
nasal administration). The effect observed was dose-indepen-
dent and had practically identical representation for all nano-
drug doses used. The effect above retained even 6 days upon
the nanodrug discontinuation in the groups of animals ad mi ni s-
tered with the doses of 1 or 5 mg/kg. Thus, the identified bet-
tering the coordination of spatial motions and of the animals’
spatial orientation ability is the result of using “L-DOPA” in a
prolonged form.
4) When studying the drugs influence upon the animals’
motor performance and their exploratory activities in the “Open
Field” test, the chronic nasal administration of L-DOPA com-
pounds in all doses used was not detected to influence on test
results, such as total distance, number of postures and visits to
the center of the field. At th e same time, it is important to note
the disappearance of grooming acts by the end of experiment
for all drugs under research, but with the high degree of confi-
dence – in the case of “Nano-L-DOPA” only. This fact may
testify the decrease in emotional reactivity/anxiety, as well as
the increase in the decision making processes in experimental
animals upon the chronic nasal administration of “Nano-L-
DOPA” and, to a smaller extent, L-DOPA.
Thus, the comprehensive preclinical efficacy of the nasal
administration of “Nano-L-DOPA” showed that, in the condi-
tions of a chronic experiment, in the background of the pro-
longed action of “Nano-L-DOPA”, a long-term increase in the
animals’ endurance under the dynamic and static loads had
been d etected. Of th e doses resea rched, t he optimal do ses are 1
mg/kg and 5 mg/kg (by L-DOPA), where the performance in-
creases by maximum (up to 35% of the background values), the
positively significant effect being retained even after the dis-
continuation of the administration. The results obtained allow
us to consider “Nano-L-DOPA” a prospective compound for
nasal administration as a drug influencing the performance.
Comparative studies of general toxicity (acute, subacute) at
the intranasal administration of the “Nano-L-DOPA” composi-
tion, conducted on 2 animal species of both genders (BALB/c
mice and Wistar rats) within the doses experimented did not
show any toxic actions of “Nano-L-DOPA”. In acute toxicity
studies, the intranasal (repeated, at short intervals) administra-
tion of “Nano-L-DOPA” in a maximum species-relevant vo-
lumes and doses was established not to be accompanied by
lethal outcomes for the animals under test. The highest sum-
mary dose of “Nano-L-DOPA” reached at repeated intranasal
administration made 540 mg/kg in BALB/c mice (by 10 mcl in
each nostril, every 5 minutes) and 150 mg/kg in Wistar rats (by
20 mcl in each nostr il, every 5 min ut es), resp ectivel y. The sa me
procedure of L-DOPA intranasal administration did not result
in any mortality of the animals under test, either. However,
transient toxic manifestations were detected at positively
smaller doses and were more evident than in administering
“Nano-L-DOPA”.
In subacute toxicity studies, the 7-day intranasal “Nano-L-
DOPA” administration in doses under research (rats 20 mg/kg,
50 mg/kg) were not accompanied by any lethal outcomes or
side effects during the administration period and within 14-day
observations after the last administration. The results of hema-
tologic and morphometric studies, pathomorphological and
pathohistological examinations did not detect any essential
differences in organs and tissues of the animals under test, as
compared to those of control animals. The results obtained in
the studies allowed us to conclude that the intranasal adminis-
tration of “Nano-L-DOPA” was a relatively safe way of admi-
nistering the drug under development. The results obtained
allow us t o forecast t hat th e intran asal way of ad ministering the
“Nano-L-DOPA” will be prospective for further clinical man-
agement thereo f.
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