matthias g. wacker, phd
TRANSCRIPT
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HOW TO DESIGN NANOCARRIERS FOR DRUG DELIVERY?
Matthias G. Wacker, PhD
Pharma Test Workshop Series 2016
NANOTECHNOLOGY IN THE PHARMACEUTICAL
INDUSTRY
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NANOTECHNOLOGY FOR THE MARKET
• Enhancing solubility of poorly soluble compounds
• Administer high doses of API in a liquid dosage form (e.g. tox studies)
• Target API to a specific site of action (e.g. Doxil®)
Source: Cumming et al. 2013, Nature Reviews Drug Discovery; www.accademia.org
I‘m more
soluble
than you!
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NANOTECHNOLOGY FOR THE MARKET
• Nanocrystal formulations are produced by milling, HPH or nanoprecipitation
• Bioavailability of compounds from BCS classes II and IV (e.g Tricor®) is
enhanced, signficantly
• Immediate release is desirable for most nanocrystal formulations
100 nm
500 nm
2 µm
5 µm
Source: Liversidge and Liversidge 2011, Adv Drug Del Rev
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NANOTECHNOLOGY FOR THE MARKET
Formulation
name
Technology Compound BCS class
Rapamune® NanoCrystal®
(Elan Drug Technologies)
Sirolimus II
Emend® NanoCrystal®
(Elan Drug Technologies)
Aprepitant IV
TriCor® NanoCrystal®
(Elan Drug Technologies)
Fenofibrate II
Megace®ES NanoCrystal®
(Elan Drug Technologies)
Megestrolacetat
e
IV
TriglideTM DissoCubeTM
(SkyePharma)
Fenofibrate II
Source: Modified from Wacker 2016, Springer Books
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NANOTECHNOLOGY FOR THE MARKET
• Nanocarriers are applied to transport API to their target
• Encapsulation of compounds into a (protective) shell
with sustained release properties
• Distribution and interaction with physiological environment
is controlled by excipients
A B
Source: Wacker et al. 2016, Beilstein J Nanotechnol
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NANOTECHNOLOGY FOR THE MARKET
• Release rate affects drug distribution profile of nanocarriers
• Sustained release is required to fulfill the drug delivery paradigm
Kidney
(Compartment 2)
Blood plasma
(Compartment 1)
Lungs
(Compartment 4)
Liver
(Compartment 3)
kel
…
Carrier Free drug
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NANOTECHNOLOGY FOR THE MARKET
Formulation name Technology Compound Type
Abraxane® Nanoparticles Paclitaxel Parenteral nanocarrier
Ambisome® Liposomes Amphothericin B Parenteral nanocarrier
DaunoXome® Liposomes Daunorubicin Parenteral nanocarrier
Depocyt® Liposomes Cytarabin Parenteral nanocarrier
DepoDUR® Liposomes Morphoine Parenteral nanocarrier
Doxil® / Caelix® PEGylated Liposomes Doxorubicin Parenteral nanocarrier
Source: Modified from Wacker 2016, Springer Books
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WHY DO NANOMEDICINES FAIL?
• Complexity of drug delivery approaches is beyond the reality of GMP
production (e.g. method transfer and scale-up)
• Translation of existing knowledge into defined product characteristics
(e.g. particle size distribution)
• Maintaining pharmaceutical quality in small and large-scale production
(e.g. in vitro tools for formulation development and quality control)
• “Trial and error“ development instead of rational formulation design
(No predictive models for the in vivo performance)
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RATIONAL FORMULATION DESIGN
Source: Wacker 2013, Int J Pharm
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CASE STUDY 1: FROM SMALL SCALE TO MEDIUM SCALE
• Perorally administered drug formulation of
mTHPC
• Optimizing formulation design and transfer
to GMP compliant manufacturing technology
• Low systemic availability but high intracellular
activity
Source: www.biolitec.com
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CASE STUDY 1: FROM SMALL SCALE TO MEDIUM SCALE
• Nanocarriers demonstrating
mucoadhesion and penetration
through the mucus layer in the
colon
• Size-controlled targeting mechanism
by epithelial enhanced
permeability and retention (eEPR)
• Demonstrating sustained release
and uptake into cancer cells
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FORMULATION DESIGN
• Define specifications with major impact on therapeutic aim
• Set up analytical methods to support early formulation development
• Choose an initial formulation design (process technology and composition)
reflecting technical and therapeutical needs
Nanoparticle formulation
Nanocarriers
Active drug targeting
Drug load / Release rate
Particle size/ shape
Specific surface design
Passive drug targeting
Drug load/ Release rate
Particle size/ shape
Surface charge/
Hydrophilicity
Nanocrystals
Particle size Release rate
Source: Modified from Wacker MG 2015, Springer Books
Nanoparticle formulation
Nanocarriers
Active drug targeting
Drug load / Release rate
Particle size/ shape
Specific surface design
Passive drug targeting
Drug load/ Release rate
Particle size/ shape
Surface charge/
Hydrophilicity
Nanocrystals
Particle size Release rate
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FORMULATION DESIGN
• Drug load and encapsulation efficiency
dose 0.15 mg/kg
non-critical parameter
• Particle size and size distribution
more than 95% within 50 - 200 nm
• Net charge
> + 30 mV
• Release rate and profile
< 20% over 5 h
Release
rate
Particle
size
Drug
load
Net
charge
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FORMULATION DESIGN
• Organic solution of drug and polymer (Eudragit® RS 100)
• Addition of non-solvent and stabilizer under defined conditions
• Precipitation of drug-loaded nanoparticles
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FORMULATION DESIGN
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FORMULATION DESIGN
• Identify most important formulation and process parameters
• Monitor the impact of process parameters on nanocarrier formulation
• Optimize process for intended manufacturing and analytical procedures
Polymer concentration
Flow rate Type of solvent
Small scale
[mg/h] Medium scale
[g/h]
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FORMULATION DESIGN
Source: Beyer et al. 2015a, Pharm Res
• Optimizing formulation design for all of the three defined parameters
• Implementing DoE to study synergies between polymer concentration and
flow rate
Solvent 1 Solvent 2
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FORMULATION DESIGN
• Validation of analytical technology required before process optimization
• Combinations of different techniques are mandatory for determining particle
size
Source: Beyer et al. 2015a, Pharm Res
Solvent 2
Solvent 1
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FORMULATION DESIGN
• Current regulations for food, cosmetics and medical devices reflect this
analytical problem
• Two different methods that are based on two different principles
• At least one method based on electron microscopy
Particle size
Dynamic light scattering
Powder diffration
Electron microscopy
AFM
TEM
SEM Analytical
ultracentrifugation
Field flow fractionation
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IN VITRO SELECTION
• Many nanocarrier devices fail to cross the mucus barrier before
being taken up by cells
• Ussing chamber experiment with a mucin-producing T84 cell layer confirms
penetration depth and uptake
Source: Beyer et al. 2015b, Pharm Res
Donor Acceptor
+
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IN VITRO SELECTION
• Fluoresence activated cell-sorting (FACS) demonstrated quantitative
accumulation of the nanocarriers
• Method is showing association
but not the uptake into the cells
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IN VITRO SELECTION
• Polymeric particles have to enter
the cytosol before releasing the
API
• Uptake of nanocarriers into the
cells will be essential for the
therapeutic approach
Source: Beyer et al. 2015b, Pharm Res
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IN VITRO SELECTION
• No standard procedure to assess
the drug release from polymer nanoparticles
• Biorelevant release testing makes it more
difficult due to colloidal excipients
• Dialysis is applied when systems are sensitive to
shearing forces
Source: Al Meslmani et al. 2015 (In preparation), J Pharm Pharmacol
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IN VITRO SELECTION
• Drug release of mTHPC was studied by online measurement under sink
conditions in a dialysis setup
• Membrane kinetics is a factor to consider for dialysis processes
Source: Xie et al. 2015, Int J Pharm
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IN VITRO SELECTION
• Biorelevant dissolution testing is more predictive for in vivo performance
• Sample and separate method for nanocrystals was applied to nanocarriers
• Sustained release was confirmed for nanoformulation 2
Source: Modified from Al Meslmani et al. 2015 (In preparation), J Pharm Pharmacol; Beyer et al. 2015b, Pharm Res
○ Pure drug ● Microformulation
■ Nanoformulation 1 □ Nanoformulation 2
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IN VITRO SELECTION
• Low dark toxicity of the formulation design
• High efficacy after uptake into cancer cells and illumination
(photosensitizer therapy)
Source: Beyer et al. 2015a, Pharm Res
mTHPC
No mTHPC
Purified nanocarriers
Non-purified nanocarriers
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INDUSTRIAL MANUFACTURE
• Transfer to medium-scale process with initial formulation parameters
obtained from DoE screening
• Manufacture in a continous-flow process
• Confirming product characteristics by TEM/SEM and DLS
Source: Beyer et al. 2015, Pharm Res
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INDUSTRIAL MANUFACTURE
• Transfer to GMP facilities of a pharmaceutical
manufacturer
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CASE STUDY 2: IN VITRO SELECTION OF BLOCK-CO-POLYMERS
• Synthesis of new blockcopolymers
• Developing polymeric formulations of model compound Dexamathasone
• Screening and selection of polymeric micelle formulations by using an
optimized set of in vitro tools
• Finding tendencies in the drug binding behavior of polymeric micelles
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FORMULATION DESIGN
• Synthesis of blockcopolymers by using a hydrophilic PEG chain and various
lipophilic side chains
• Determining composition by NMR analysis
Polyethyleneglycol
Buthylmethacrylate (BuMA)
Benzylmethacrylate (BzMA)
Acrylamidobenzylacrylate (AAmBzA)
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IN VITRO SELECTION
• Determination of plasma halflife via fluorescence resonance
energy transfer (FRET) assay
• Determination of CMC
Polymer CMC [mg/L] Plasma t1/2 [h[
BP001 0,43 23,1
BP002 0,36 11,6
BP003 0,25 11,6
BP004 0,93 28,9
BP005 0,53 14,4
BP006 0,69 16,5
BP007 0,55 -
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FORMULATION DESIGN
• Optimizing preparation process for nanocarrier formulations
• Loading Dexamethasone to blockcopolymers by using solvent
evaporation method
• Characterization by DLS and Cryo-TEM
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IN VITRO SELECTION
• Polymers have been loaded with
highest drug load
• Samples are sensitive to filtration
procedures
• No standard technology can be
applied
Source: Modified from Al Meslmani et al. 2015 (In preparation), J Pharm Pharmacol
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IN VITRO SELECTION
• Drug release was determined by using dialysis bag method
• Complete release of compounds from the polymeric material was determined
in presence of 10% of foetal calf serum
• Significant differences in the release profiles under accelerated conditions
● Pure drug
♦ BP002
■ BP006
Source: Janas et al. 2015, J Pharm Sci (In preparation)
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CASE STUDY 3: OPTIMIZING MEDIUM-SCALE MANUFACTURE
• Long-circulating parenteral nanocarriers for drug delivery with optimal toxicity-
to-efficacy ratio
• Accumulation by taking advantage of enhanced permeability and retention
(EPR) effect
• Optimized medium-scale manufacturing process
• Confirm efficacy and pharmaceutical quality
Formulation design/
Preformulation
Process optimization
Quality and efficacy
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CASE STUDY 3: OPTIMIZING MEDIUM-SCALE MANUFACTURE
• Formulation of the photosensitizer mTHPC for
intravenous injection
• Embedding compound into PLGA-PEG
nanoparticles
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FORMULATION DESIGN
• Drug load and encapsulation efficiency
dose 0.15 mg/kg
> 60% acceptable for administration
• Particle size and size distribution
50 - 150 nm, PDI < 0.1
High in vitro stability in serum
• Net charge
< -15 mV
• Release rate and profile
< 20% in 1 h
Release
rate
Particle
size
Drug
load
Net
charge
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FORMULATION DESIGN
• Selection of PLGA-PEG as long-circulating drug carrier material
• Preformulation studies confirmed the use of Pluronic F68 as stabilizing agent
• Solvent-to-non-solvent ratio was set 1:10 to enable freeze drying of the final
suspension
• Preformulation studies confirmed an absolute flow rate of 2.2 mL/min
Preformulation studies
Solvent-to-non-solvent (SNS) ratio
Absolute flow rate
Type of stabilizer
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FORMULATION DESIGN
• Identify a group of process parameters that may be relevant to product
characteristics
• Optimization of process parameters in two steps
Polymer
conc.
Stabilizer
conc.
Gas
pressure
Drug
conc.
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PROCESS OPTIMIZATION
• Screening for independent variables with greatest impact on encapsulation
efficiency
• Selecting independent variables for further optimization
Source: Data taken from Villa Nova et al. 2015, Int J Pharm
Stabilizer and
polymer concentration
N2 pressure
and drug concentration
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PROCESS OPTIMIZATION
• Optimizing formulation by testing various levels for a limited number of
variables
• Selecting optimal formulation design for further processing
Source: Data taken from Villa Nova et al. 2015, Int J Pharm
Polymer concentration
Stabilizer concentration
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PROCESS OPTIMIZATION
• Confirming analytical techniques by using TEM and SEM
Source: Villa Nova et al. 2015, Int J Pharm
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QUALITY AND EFFICACY
• Quality parameters
in vitro stability in physiological media
in vitro release in an optimized release test
• Efficacy parameters
Light and dark toxicity
in vivo distribution
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QUALITY AND EFFICACY
• Currently no compendial release test for nanoformulations available
• Dispersion releaser technology allows micellar and liposomal structures by
using dialysis technique in a USP1/2 system
Source: Janas and Wacker, German Patent Application No. DE102013015522.3
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QUALITY AND EFFICACY
• Stability of formulations in presence of 0 to 90% of serum
• No aggregation in physiological medium observed
• Drug release testing by using an optimized dialysis method
• Reproducibility of manufacturing process within the defined specification
range has been demonstrated
○ Batch 1
● Batch 2
Source: Villa Nova et al 2015, Int J Pharm; Janas and Wacker, German Patent Application No. DE102013015522.3
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QUALITY AND EFFICACY
• High efficacy of formulation design when illuminated
• Lower toxicity observed compared to the existing drug formulation (Foscan®)
Source: Villa Nova et al 2015, Int J Pharm
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QUALITY AND EFFICACY
• Photosensitizers have fluorescent
properties but they are decreasing
with photodynamic activity
• No signal in deeper compartments
observed but no precipitation or
depot formation at the injection site
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ACKNOWLEDGEMENTS
Dr. Mukul Ashtikar Prof. Dr. Jennifer Dressman
Dr. Bassam Al Meslmani Prof. Dr. Marcos Bruschi
Susanne Beyer Prof. Dr. Michael Parnham
Monica Villa Nova
Christine Janas
Aline Moosmann
Xie Li
Laura Jablonka
Manuela Thurn