Pastillation Technology Based Design &
Development of Oral Modified Release
Multiparticulate Drug Delivery System
Presented by:
Prof. B. Mishra
Professor & Former Head,
Department of Pharmaceutics,
Indian Institute of Technology
(Banaras Hindu University)
Varanasi- 221 005
Components of Research
Background
• Lipid based multiparticulate drug delivery
system
• Doxofylline as potential anti-asthmatic agent
Experimental work
• Development of Immediate and controlled
release pastilles
• Development of pulsatile release pastilles
• In vivo study
2
Lipid based multiparticulate
system
Nanoparticles
Pellets/Beads
Microparticles
Granules
3
Pastillation
• Pastillation is a widely used technique in chemical, petrochemical and
agrochemical industries
• It is used for the solidification of dusty hazardous powders of
chemicals into pastilles (hemispherical solidified units of uniform size)
which eases their handling.
• In this process, the drops of chemical substances in molten state are
deposited on a cooled stainless steel surface for rapid solidification to
generate pastilles of uniform dimensions.
• Depending on the size of the drops and the physical properties of the
melt, the drops flatten to a certain extent.
• The solidified droplet, therefore, has the typical pastille-like shape. The
production process can be easily carried out at large scale with the
help of specially designed equipments called ‘Rotoformer’.
4
Pastillation equipment
5
Why pastillation in DDS?
•
•
•
•
•
•
•
•
•
Suitable for hygroscopic drug as the processing of the ingredients is absolutely
free from use of water.
Environment friendly as involves no use of organic solvents.
Pastilles are stable and highly uniform in shape.
Pastilles can be produced in a wide range of sizes with diameters ranging from
1 to 30mm.
Pastilles have higher bulk density and better packing properties than powders
and therefore, ideal for handling, filling and packaging.
The conversion of a bulk molten liquid directly into individual solidified units
provides dust free working environment.
Single step process involving one equipment (melting of lipid, mixing of drug
and excipients followed by solidification).
Reduced energy costs due to absence of number of processes of formulation.
Ease of packaging as the pastilles of smaller dimension can be capsule filled
while the larger ones can either be strip packed or filled directly in
sachets/bottles.
6
Components of Research
Background
• Lipid based multiparticulate drug delivery
system
• Doxofylline as potential anti-asthmatic agent
Experimental work
• Development of immediate and controlled
release pastilles
• Development of pulsatile release pastilles
• In vivo study
7
Doxofylline
•
•
•
•
•
Ist Marketed product in India
Product: DOXOBID (Doxofylline tablets 400mg)
Company: Dr. Reddy’s Labs.
Label Claim:
Each uncoated tablet contains:
Doxofylline 400mg
Indication :used as Bronchodilator in Asthma
& chronic obstructive pulmonary
disease(COPD)
Dose
: 400mg IR is given 2-3 times daily
Chemical Name: 2-(7-theophyllinemethyl)-1,3 dioxolane
Molecular Formula: C11H14N4O4
Formula weight: 266
Melting Point: 144-145.5°C
Solubility: Freely Soluble in chloroform and Dichloromethane
soluble in acetone, sparingly soluble in water and ethyl acetate
Storage: Store in cool, dark and dry place.
8
Pharmacokinetic profile
Absorption
• Absorption Bioavailability
: 62.6%
Therapeutic Drug Concentration
• Chronic Bronchitis
: 8-20 µg/ml
• Time to peak concentration (tmax)
: 1.19 hours
• The steady state is reached within 6hrs
: 9.43 µg/ml
• Area under the curve, AUC
: 69.5 hr×µg/ml
Distribution
• Protein Binding
: 48%
• Distribution Half Life
: 0.19 hr
• Volume of distribution
: 1 L/kg
Metabolism
• Metabolism sites & kinetics: Liver >90%
• Metabolites: Hydroxyethyltheophylline (inactive)
Excretion
• Kidney: Less than 4% of an administered dose of doxofylline is excreted unchanged in the urine
• Total Body Clearance: 444-806µg/ml
• Elimination Half life: Parent compound – 7 to 10hrs
9
Objectives of the research work
To explore pastillation to design a platform technology
for the development of novel and unique modified
release drug delivery system
PART I
To design a immediate and controlled release formulation of
doxofylline using pastillation technology
PART II
To design a pulsatile release formulation of doxofylline
using pastillation technology
PART III
To evaluate pharmacokinetic behavior of the developed
formulations in animal model
10
In-house laboratory scale device
for pastillation
Transformer
Heating coil
Ceramic insulation
Glass syringe
Needle
Pastilles
Shaft
Cold plate
Ice tray
11
Operating parameters
Factorial design using MINITAB®
Sl No.
Factors
Low (-)
High (+)
1.
Needle dimensions (X1)
16G
20G
2.
Dropping height (X2)
1 cm
3 cm
3.
Temperature of plate (X3)
4 °C
25 °C
12
Evaluating parameter
Contact angle measurement
Method of analysis (Photographic method)
The photographs of the pastilles were taken from the horizontal
side at their contact with the plate and the snaps were then
proportionally magnified and processed using Adobe Photoshop®
software. The angle of contact was determined manually and
confirmed mathematically using the following equation:
θ = 2tan−12h/d
Where h is the height of the drop from the plate and d is the
diameter of the drop. Both of these dimensions can be measured from
the photograph for calculating the contact angle.
13
Contact angle of pastilles
14
Formulation batches (for optimization)
Sl. No.
Batches
X1
X2
X3
1.
A1
16G
1 cm
4 °C
2.
A2
16G
1 cm 25 °C
110°
3.
A3
16G
3 cm
4 °C
100°
4.
A4
16G
3 cm 25 °C
80°
5.
A5
20G
1 cm
4 °C
120°
6.
A6
20G
1 cm 25 °C
115°
7.
A7
20G
3 cm
4 °C
95°
8.
A8
20G
3 cm 25 °C
85°
Avg. Contact
angle (Y1)
121°
15
Effect of needle size and dropping
height on contact angle
(A) Response Surface 3D plot
(B) Contour plot
16
Effect of temperature of plate and
dropping height on contact angle
(A) Response Surface 3D plot
(B) Contour plot
17
Effect of needle size and temperature
of plate on contact angle
(A) Response Surface 3D plot
(B) Contour plot
18
Flow property of pastilles based
on their contact angle
Flow property
Contact Angle
Poor
60-85°
Fair
85-105°
Good
105-125°
19
Optimized parameters for highest
achievable (desirable) contact angle
Sl No.
Optimized parameters
1.
Needle dimensions (X1)
20 G
2.
Dropping height (X2)
1 cm
3.
Temperature of plate (X3)
4 °C
20
Formulation chart
Composition
B-1
B-2
B-3
B-4
g/batch
B-5 B-6
DOX
0.5
0.5
0.5
0.5
0.5
0.3
0.4
0.5
0.5
0.5
2.0
2.0
2.0
2.0
2.0
2.0
1.7
1.7
1.7
-
-
-
-
-
-
0.3
1.5
0.75
-
0.3
-
-
0.3
0.3
-
-
-
PEG 6000
-
-
0.3
-
-
-
-
-
-
PEG 400
Colloidal
75
silicon dioxide
Drug content
100.56
Uniformity (%) ± 0.93
-
-
-
0.3
-
-
-
-
-
Stearic acid
Benefat
PEG 4000
2.0
B-7
B-8
B-9
B-10
98.89 ±
1.23
21
Evaluation
• Drug content uniformity
(20 ml water added to pastilles eq. to 10 mg drug and heated at 75°,
sonicated, cooled and volume made upto 25 ml. 5 ml filtered and
measured spectrophotometrically)
• Drug release study
(USP Appt. II, 500 ml of 0.1 N HCl, 50 rpm, 37±0.5°C for 2 h
followed by pH 6.8 phosphate buffer for next 22 h)
• Scanning electron microscopy
(The morphological structure of the prepared pastilles was observed
using scanning electron microscope (FEI Quantum 200E Instrument)
• Stability studies
(pastilles packed in 30 ml HDPE bottles kept in 40°C/75%RH for 3
months storage conditions in stability chamber (Narang Scientific Works
Pvt. Ltd., New Delhi, India))
22
Analytical method
• UV–VIS spectrophotometry (Hitachi U-1800)
• Standard curves of doxofylline were prepared in water,
0.1 N HCl (pH 1.2) and phosphate buffer solutions (pH
6.8) in the concentration range of 5–35 μg/ml.
• A UV visible spectrum of doxofylline showed a
characteristic peak at 273 nm in all the solutions.
• The standard curve was plotted as drug concentration
(μg/ ml) vs. absorbance plot. Curve fitting was done by
linear regression analysis using Microsoft Excel program
23
Standard Curves of Doxofylline
24
Effect of pore former & type of
buffer media on drug release
25
Effect of drug load on drug release
26
Effect of benefat (lipid pore former)
concentration on drug release behavior
R2=0.983
27
Scanning electron microscopy
(A) Batch B1 (B) Batch B1 at higher magnification
(C) Batch B10 (D) Batch B10 at higher magnification
28
Drug release profiles of initial
and 3 months stored samples
Drug content uniformity
1M-98.66%
2M- 97.12%
3M-96.46%
Stability
study
at
40°C/75%RH
indicate
stable formulation with
no change in physical
appearance,
drug
release
and
drug
content
29
Components of Research
Background
• Drug delivery system
• Therapeutic application
Experimental work
• Development of immediate, controlled and
pulsatile release pastilles
• In vivo animal study
30
Formulation chart
Ingredients
DOX (mg)
PEG 4000 (mg)
Colloidal silicon dioxide (mg)
Enteric coat 1
P-I P-II P-III
500 500 500
2000 2000 2000
75
150
-
-
-
P-IV
500
2000
75
P-V
500
2000
75
P-VI
500
2000
75
10 ± 5 %*
-
-
(5 g Eudragit L100 55 and 0.25 g triethyl
citrate (plasticizer) & 2% talc in 100ml
methanol
Enteric coat 2
(5 g Eudragit L100 55 and 0.5 g triethyl
citrate (plasticizer) & 2% talc in 100ml
methanol
Floating layer
10 ± 5 %* 10 ± 5%*
-
-
-
-
-
20 ± 5%#
(1g HPMC K15M, 0.1 g triethyl citrate
(plasticizer) in 100 ml IPA DCM mixture
(60:40 v/v). NaHCO3 crushed and passed
through #100 mesh & 2% talc was
dispersed in the above solution
* Amount of enteric coat applied was calculated in terms of percentage weight gain with respect to the weight of uncoated pastilles
# Amount of floating coat applied was calculated in terms of percentage weight gain with respect to the weight of enteric coated pastilles 31
Evaluation
• Assay
• Drug content uniformity
• Drug release study
(USP Appt. II, 500 ml of 0.1 N HCl, 50 rpm, 37±0.5°C for
2 h followed by 2 h followed by pH 6.8 phosphate buffer
for next 2 h)
• Scanning electron microscopy
• Stability studies (40°C/75%RH for 3 months)
32
Contact angle
Pastilles with A) desired contact angle (above 85°), B) with
contact angle ≤ 45°, C) with contact angle above 70°
33
Explanation for formation of
flat pastilles
Contact angle improvement of
PEG pastilles at large scale
Friability
B-I
:0.596%
B-II
:0.104%
34
Assay and drug content uniformity
Assay (%)
Drug content
uniformity
P-I
100.12 ± 1.11
100.19 ± 2.13
P-II
100.09 ± 1.91
99.98 ± 2.21
P-III
99.61 ± 2.17
98.89 ± 1.81
P-IV
98.12 ± 1.21
99.01 ± 0.91
P-V
98.08 ± 2.19
98.21 ± 1.27
P-VI
99.06 ± 1.98
99.12 ± 2.12
35
Drug release profile
36
Scanning electron microscopy
Surface morphology of coated pastilles using SEM A) Batch P-IV, B) Batch P-V, C) Batch P-VI
37
Coated PEG pastilles floating in
dissolution medium
38
Dissolution of initial and three
months stored samples
39
Conclusion
A novel technology ‘pastillation’ was successfully
employed for the development of immediate
release pastilles. This dosage form after coating
with enteric and floating coat were also found to be
effective to achieve the required delay in drug
release for treatment of nocturnal asthma. The
prepared formulations showed desired drug release
profile with an initial lag phase in the in vitro drug
release study. The in vivo pharmacokinetic study
would be helpful in further evaluating the potential
of this formulation in the chronotherapeutic
treatment of nocturnal asthma.
40
Components of Research
Background
• Drug delivery system
• Therapeutic application
Experimental work
• Development of controlled release pastilles
• Development of pulsatile release pastilles
• In vivo animal study
41
In-vivo animal study
Animal study protocol were approved by the
Animal Ethical Committee
of Banaras Hindu University.
(No. 2010-11/153)
Male albino rats of 250 ± 20 g
12 h fasting prior to dosing
5.70 mg drug/kg body weight administered orally
Pastilles were administered with 5.0 ml of
1.0% aqueous polyvinyl alcohol solution
Blood (0.5 mL) was collected via retro-orbital vein
0, 0.25, 0.50, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 h
Blood samples were allowed to clot
They were centrifuged for 10 min at 3000 rpm
The serum obtained was transferred to clean tube for storage
at −20 °C until analysis
42
Study design of pharmacokinetic
studies
For controlled release pastilles
PEG Pastilles (IR)
Stearic acid pastilles (CR)
For pulsatile release pastilles
PEG Pastilles
(uncoated)
PEG Pastilles
(enteric coated)
PEG pastilles (enteric
coated with floating layer)
43
Serum drug estimation
Drug separation from serum by liquid-liquid extraction method
Serum (containing drug) (500 μl) + methanol (400 μl)
Vortexed (8 min) &
centrifuged at 3500 rpm for 10 min
Supernatant (400 μl)
Evaporated in vacuum oven at 40°C
Residue + mobile phase (200 μl)
Reconstituted
Reconstituted sample (20 μl ) injected for HPLC analysis
44
Serum drug estimation
Serum drug estimation by Reverse phase HPLC method
Chromatographic conditions:
Column: C18 reverse-phase 250×4.6 mm 5 μm ODS2 column (Waters, Ireland)
Mobile phase: 18:82 acetonitrile–12.5 mM potassium dihydrogen orthophosphate
buffer (pH adjusted to 3.0 with orthophosphoric acid)
Flow rate: 1 ml/min
Injection volume: 20 μl
λmax: 275 nm
Retention Time: 9.75 min
45
Pharmacokinetic estimation
Cmax
peak serum concentration
Tmax
time to reach peak concentration
AUC0-t
area under the curve from time zero to last
measured concentration
HVD t50% Cmax
time span during which the serum concentrations
were at least 50% of the Cmax
R∆
ratio between the HVD t50% Cmax values of the test
formulation and the drug suspension
Kinetica® software
GraphPad Prism® software
46
Chromatographic Area under the peak
HPLC chromatograms and
Calibration curve of doxophylline
extracted from serum
500000
450000
400000
350000
300000
250000
200000
150000
y = 188.19x - 628.05
R² = 0.9999
100000
50000
0
0
500
1000
1500
2000
Doxofylline concentration (ng/ml)
2500
47
Pharmacokinetic profile of PEG
and lipid based pastilles
48
Pharmacokinetic data of PEG and
lipid based pastilles
Pharmacokinetic
PEG based
Lipid based
parameters
pastilles
pastilles
Cmax (ng/ml)
31.83 ± 1.28
16.32 ± 3.69
Tmax (h)
0.75 ± 0.06
6.0 ± 1.58
AUC last (ng/ml*h)
182.56 ± 19.98
210.39 ± 59.6
HVD (h)
3.18 ± 0.21
11.43 ± 1.52
$R∆
-
3.59
$ R∆
=of 1.5, 2 and >3 indicates, low, intermediate and strong sustained release effect, respectively
Data are shown as mean + SEM
49
Pharmacokinetic profile of uncoated
and coated PEG pastilles
50
Pharmacokinetic data of uncoated
and coated PEG pastilles
P-II
(Uncoated
pastilles)
P-V
(Enteric coated
pastilles)
P-VI
(Enteric &
floating coated
pastilles)
Cmax (ng/ml)
31.83 ± 1.28
30.92 ± 2.12
25.12± 2.41
Tmax (h)
0.75 ± 0.06
3.0 ± 0.27
6.0 ± 0.82
182.56 ± 19.98
201.47 ± 29.7
241.68 ± 42.7
3.18 ± 0.21
4.23 ± 0.15
6.70 ± 0.13
-
1.33
2.11
Pharmacokinetic
parameters
AUC last
(ng/ml*h)
HVDt50% Cmax (h)
R∆
Data are shown as mean + SEM
51
Gamma scintigraphic method
Radiolabeling of Pastilles
Technetium (99mTc) was chosen for radio-labeling of the pastilles because of its
short half-life of 6 hrs and very less amount of electron emission
5 mg
stannous
chloride
dihydrate (1
mg/ml in 10%
acetic acid) of
pH 7.5
(adjusted with
0.5M
NaHCO3
TLC (Silica Gel)
After 99% reduction
5 mg
stannous
chloride
dihydrate (1
mg/ml in 10%
acetic acid) of
pH 7.5
(adjusted with
0.5M
NaHCO3
After 2 min
radiolabeling efficiency was evaluated by TLC-SG
strips as stationary phase & acetone as mobile phase
52
Gamma scintigraphic method
Stability of radiolabeled pastilles
pH 1.2 0.1N HCl
1g pastilles
pH 6.8 buffer
pH 7.2 buffer
Kept under
stirring in a water
bath maintained at
37° C for 6 hr
0.2 ml filtered solution
checked for radioactivity by
auto gamma counter
53
Study design of gamma
scintigraphy
For pulsatile release pastilles
Male albino rats of 250 ± 20 g, 12 h fasting prior to dosing
5.70 mg drug per kg body weight administered orally
After light anaesthetization
serial scintigraphic examination was done at 0.5, 1, 1.5, 2, 3, 4
and 5, 6 hrs depending on type of formulation using a large
field view gamma camera
Images were recorded for a preset time of 1 min/view to
include the 140 keV photopeak of 99mTc
PEG Pastilles
(uncoated)
PEG Pastilles
(enteric coated)
PEG pastilles (enteric
coated with floating layer)
54
Gamma scintigraphic set up
A
B
C
D
55
Stability data of radiolabeled
pastilles
P-II
(Uncoated
pastilles)
P-V
(Enteric
coated
pastilles)
P-VI
(Enteric &
floating
coated
pastilles)
1.2
0.13
0.21
0.16
6.8
0.25
0.32
0.27
7.2
0.36
0.34
0.31
pH
56
Gamma scintigraphy study of
uncoated PEG pastilles
A
B
Gamma Scintigraphy study of uncoated PEG pastilles on rats at time point
(A) 0.5 hr and (B) 1 hr
57
Gamma scintigraphy study of
uncoated PEG pastilles
OBSERVATION:
Attenuation of radioactivity within 0.5 hrs.
INFERENCE:
In the presence of gastric fluid, PEG matrix dissolved completely
and behaved as an immediate release dosage form.
58
Gamma scintigraphy study of
enteric coated PEG pastilles
B
A
D
C
E
Gamma Scintigraphy study of enteric coated PEG pastilles on rats at time
59
point (A) 0.5 hr and (B) 1 hr, (C) 1.5 hr, (D) 2 hr and (E) 3 hr
Gamma scintigraphy study of
enteric coated PEG pastilles
OBSERVATION:
The pastille maintained its matrix integrity till 1.5 hrs in the
gastric region. At 2 hrs the pastille was located in the jejunum
area where it started to dissociate.
INFERENCE:
No influence of gastric fluid on the enteric coating applied on the
pastilles.
60
Gamma scintigraphy study of
pastilles with floating coat
A
B
C
D
E
F
Time point (A)1 hr, (B) 2 hr and (C) 3 hr, (D) 4 hr, (E) 5 hr and (F) 6 hr
61
Gamma scintigraphy study of
pastilles with floating coat
OBSERVATION:
The pastille was retained in the stomach for 2 h. In the next hour,
the intact pastille migrated into the jejunum. Further, in the 4th
hour the dosage form was found to reach the ileum region where
it started to disperse. The image of 6th hour shows complete
disintegration of the dosage form.
INFERENCE:
This indicates that the floating coat is not only valuable to retain
the dosage form in the stomach for more than two hours but also
to protect the enteric coat from alkali environment for an hour.
62
Conclusion
•
The pharmacokinetic and gamma scintigraphic imaging confirms
the ability of the formulations to release the drug only after a
desired period of time as specifically required for the treatment of
noctural asthma.
•
The results are also in agreement with the in vitro drug release
study which indicates the efficiency of the coating system.
•
The present study also confirms the ability of PEG based pastilles
to act as an immediate release dosage forms.
•
Further coating of the PEG pastilles with appropriate polymers can
significantly impart functional properties to modify the release of the
drug in a pre-determined fashion.
63
Major findings
• Use of pastillation technology for the first time in pharmaceutical
field
• Novel drug delivery system “PASTILLES”
were successfully formulated as:

immediate release dosage form

pulsatile release dosage form

sustained release dosage form
64
Important references
•Cheboyina, S. and Wyandt, C.M., Wax-based sustained release matrix pellets prepared by a novel freeze
pelletization Technique . I. Formulation and process variables affecting pellet characteristics, Int J Pharm, 359, 158166, 2008.
•Reitz, C. and Kleinebudde, P., Spheronization of solid lipid extrudates, Powder Technol, 189 238-244, 2009.
•Van G.F., Rao Y.M., Modified
No.WO2009/112436A1, 2009.
release
composition
comprising
doxofylline,
Patent
application
•Huang, H.F., Lu, Y., He, H.B., and Tang, X., Preparation and bioavailability of sustained-release doxofylline pellets
in beagle dogs, Drug Dev Ind Pharm, 34, 676-682, 2008.
•Gils, P.S., Ray D., Sahoo P.K., Controlled release of doxofylline from biopolymer based hydrogels, Am J Biomed
Sci, 2, 373-383, 2010.
•Gannu, R., Bandari S,. Sudke S.G., Rao, M. and Shankar, B.P., Development and validation of a stability-indicating
RP-HPLC method for analysis of doxofylline in human serum. Application of the method to a pharmacokinetic
study, Acta Chromatographica, 9,149-160, 2007
•Sandvik Materials Technology. Available at:http://www.processsystems.sandvik.com/
•Rxlist. Available at: www.rxlist.com
•Cipla
Therapeutic
Index,
Respiratory
drugs,
Zordox.
CiplaDoc.
http://www.cipladoc.com/therapeutic/admin.php?mode=prod&action=disp&id=650
Available
at:
•Aulton, M.E., Dyer, A.M. and Khan, K.A., The strength and compaction of millispheres, Drug Dev Ind Pharm,
20, 3069-3104, 1994.
•Breitenbach, J., Melt extrusion: from process to drug delivery technology, Eur J Pharm Biopharm, 54, 107-117,
65
2002.
Publications from research work
S. No
Publication Details
1.
Shukla D, Chakraborty S, Singh S, Mishra B. Doxofylline: a promising
methylxanthine derivative for the treatment of asthma and chronic obstructive
pulmonary disease. Expert Opin Pharmacother. 10(14): 2343-2356, 2009.
Shukla D, Chakraborty S, Singh S, Mishra B. Lipid based oral multiparticulate
formulations – Advantages, technological advances and industrial applications.
Expert Opin Drug Deliv. 8(2):207-224, 2011.
Shukla D, Chakraborty S, Singh S, Mishra B. Pastillation: A novel technology for
development of oral lipid based multiparticulate controlled release formulation.
Powder Technol. 209 (1-3): 65-72, 2011.
Shukla D, Chakraborty S and Mishra B. In vitro and in vivo evaluation of
multilayered pastilles for chronotherapeutic management of nocturnal asthma.
Expert Opin Drug Deliv 9(1):9-18, 2012
Shukla D, Chakraborty S and Mishra B. Evaluation of in vivo behavior of
controlled and pulsatile release pastilles using pharmacokinetic and γ-scintigraphic
techniques. Expert Opin Drug Deliv 9(11): 1333-1345, 2012.
2.
3.
4.
5.
Impact
Factor
3.205
4.896
2.080
4.896
4.896
66
Dr. (Mrs) Dali Shukla
This Presentation is taken from the Ph.D. Thesis of Mrs Dali Shukla who has worked
under my direct supervision.
Varanasi Ghats
Lord Vishwanath (Varanasi)
BHU Gate
Vishwanath Temple (in BHU)
IIT(BHU), Varanasi
Department of Pharmaceutics
THANK YOU