usp chemical medicines & excipients-consideration of novel formulations

Track I, Session II: Chemical

Medicines and Excipients-

Consideration of Novel

Formulations Wednesday, April 17, 2013 (11:30 a.m. to 1:30 p.m.)

IPC–USP Science & Standards Symposium

Partnering Globally for 21st Century Medicines

Moderator: Albinus D’Sa, Ph.D. US Food and Drug Administration-India

Solid Oral Formulations Advances

Dr. Sukhjeet

Panacea Biotec

Solid Oral Formulation Advances

During the past three decades, due to the evolving discipline of

biopharmaceutics, pharmacokinetics and pharmacodynamics, significant

advances have been made in the area of drug delivery.

Advances in drug delivery Technologies

Controlled drug delivery

Oros

matrix or reservoir system

Site specific deliver systems

Gastroretentive

Colon Targeted

Bioavailability enhancement

Nanocrystals

solid dispersion

hot melt extrusion

4

5

BIOAVAILABILITY ENHANCEMENT OF POORLY

SOLUBLE DRUGS

Solid Oral Formulation Advances Bioavailability Enhancement of Poorly Soluble Drugs

6

Oral bioavailability of drugs depends on its solubility and/or

dissolution rate.

40% of new chemical entities currently being discovered

are poorly water soluble. Therefore major problems

associated with these drugs was its very low solubility in

biological fluids, which results into poor bioavailability after

oral administration.

Many of these potential drugs are abandoned in the early

stages of development due to the solubility problems.

It is therefore important to realize the solubility problems of

these drugs and methods for overcoming the solubility

limitations are identified so that potential therapeutic

benefits of these active molecules can be realized.

Nanocrystals

Solid Dispersion

7

Solid Oral Formulation Advances Bioavailability Enhancement of Poorly Soluble Drugs

NANOCRYSTALS

Nanocrystals

They are nanoparticles with a crystalline character with a size in the

nanometer range

Nanocrystals are composed of 100% drug; there is no carrier material

Increased dissolution velocity

Increased saturation solubility

Increased cellular uptake – endocytosis , phagocytosis, Peyer’s patches??

9

10

Source : Nanotechnology in Ireland: A Snapshot

http://www.sciencecouncil.ie/media/icsti040714_nanotechnology_snapshot.pdf

Nanocrystals



Nanocrystals Advantages

Enhanced oral bioavailability

Improved dose proportionality

Increased drug loading

Reduced food effects

Suitable for administration by all routes

Possibility of sterile filtration due to decreased particle size range

Simple composition - Does not require novel excipients, less regulatory issues

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Comparative PK Profile of Immunosuppressant in animals

Case Study – Effect of particle size

PK Parameter

Coarse

API~10microns

Micronized

API~1.5microns

Nanoparticulate

API~less than

1microns

Drug in Solution

AUC(0-t)

(hr*ng/ml) 194.66 494.08 1391.20 976.86

Animal PK study Results – Statistical Analysis

0

5

10

15

20

0 4 8 12 16 20 24 28 32 36 40 44 48

Co

ncen

trati

on

(n

g/m

l)

Time (hr)

Pharmacokinetic Profile Comparison Coarse API~10microns

Micronized API~1.5microns

Drug in Solution

Nanoparticulate API~less than 1microns

Nanocrystals- Marketed Preparations

Tradename Drug Indication Company Status

Rapamune® Rapamycin Immunesuppressive Wyeth marketed

Emend® Aprepitant Anti emetic Merck marketed

Tricor® Fenofibrate Hypercholesterolemia Abbott marketed

Megace ES® Megestrol Anti anorexic Par Pharmaceutical

Companies marketed

Triglide® Fenofibrate Hypercholesterolemia First Horizon

Pharmaceuticals marketed

Invega

Sustenna®

Paliperidone palimtate Treatment of

schizophrenia

Johnson and Johnson marketed

Semapimod® Guanylhydrazone TNF-α inhibitor Cytokine

Pharmasciences Phase II

Paxceed® Paclitaxel Anti inflammatory Angiotech Phase III

Theralux® Thymectacin Anti cancer Celmed Phase II

Nucryst® Silver Anti bacterial Nucryst

Pharmaceuticals Phase II

13

Nanocrystals Preparation Methods

Precipitation (Bottom up)

Milling (Top down)

Homogenization (Top down)

Top down and Bottom up

14


Milling (Top down):

In this method, pearl, bead or ball mills can be utilized to prepare a nanocrystal

formulation.

The drug substance and the stabilizer are dispersed in the dispersion medium, and

this mixture is then put into a grinder chamber. Balls are rotated at a very high

speed and particle size of the drug gets smaller until nanocrystals are obtained.

Physicochemical characteristics of the nanocrystals depend on the number of

milling balls, the amount of drug and stabilizer, milling time and speed, type of

grinding chamber and temperature.

15


Homogenization (Top down)

Ultasonification: Ultrasonic probes are used

to decrease the particle size in liquid or solid

dispersed phase.

High Pressure Homogenization;

Microfluidizers homogenizers: (Insoluble Drug Delivery – Particles, IDD-

P™ technology) is utilized to achieve production of submicron particles of

poorly soluble drugs.

Piston gap Homogenizers: is performed in water (DissoCubes®), water

mixtures or nonaqueous media (Nanopure®)

Top down and Bottom up :

Both Bottom up and Top down methods are used together eg. NanoEdge technology in

which precipitation is followed by high pressure homogenization. 16


Advantages and disadvantages

Technology Advantages Disadvantages

Precipitation •- finely dispersed drug

•- good control of desired size

•- needs to be stabilized

•- organic solvent residue

•- not universally applicable, only drugs

with certain properties are possible (e.g,

soluble in at least one solvent)

Milling •- low energy technique

•- proven by 4 FDA approved drugs

•- residue from milling media

•- can be a slow process (several days)

•- needs to be stabilized

•- large batches difficult to produce due to

size of milling chamber

Homogenization

•- universally applicable

•- no problem with large batches

•- fast method (several minutes possibly)

•- high energy technique

•- great experience needed

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Nanocrystals- Characterization

Characterization technique for drug Nanocrystals

Analytical purpose Analytical techniques Conclusion from the results

Structural analysis Optical microscopy

SEM, TEM, AFM

BET

Size distribution, flocculation tendency,

detection of large particles,

surface morphology of bulk and single

particles,

Porosity, surface area

Solid state analysis DSC, PXRD, Raman spectroscopy,

IR spectroscopy,

Hot stage microscopy

Amorphous content, polymorphism

Particle size analysis Laser Diffraction , Dynamic light

scattering, coulter counter

Size and size distribution

Surface charge characteristics laser Doppler anemometry (Zeta

potential), Capillary Zone

electrophoresis

Agglomeration tendency

stability prediction

Rheological assessment Rheometer (Cone and plate,

rotational cylinder

Viscosity

18

19

Challenges in evaluation of nanocrystal

formulations

Dissolution Studies

1. What is a suitable dissolution method for drug nanocrystals?

2. How to separate undissolved nanocrystals from dissolution sample?

It is very important to separate dissolved particles before analysis, filtration using filters with pore sizes

of 0.1micron result in predictive dissolution profiles.

In situ analytical techniques, which avoid the need to separate dissolved API, are also promising

approach to assess nanocrystal dissolution

AMORPHOUS SOLID

DISPERSIONS

Solid Dispersion

Group of solid products consisting of at least two different

components, generally a hydrophilic inert carrier or matrix and a

hydrophobic drug.

The carrier can be either crystalline or amorphous in nature.

The drug can be dispersed molecularly, in amorphous particles

(clusters) or in crystalline particles

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Pharmacokinetic profile of tacrolimus in animal model.

Solid Dispersion

Conventional Dispersion

Solid Dispersion Classification

Simple Eutectic Mixtures

Solid Solutions

Glass Solutions and Glass Suspensions

Amorphous Precipitations in a Crystalline Carrier

Compound or Complex Formation;

Combinations of the previous five types.

23


Simple Eutectic Mixtures : These are prepared by rapid solidification of the

fused melt of two components that show complete liquid miscibility but

negligible solid–solid solubility. In a simple eutectic mixture, the drug is

precipitated out in a crystalline form.

Solid Solutions : The two components crystallize together in a homogeneous

one-phase system.

Glass Solutions and Glass Suspensions: A glass solution is a

homogeneous glassy (amorphous) system in which a solute dissolves in the

glassy carrier. A glass suspension refers to a mixture in which precipitated

particles are suspended in a glassy solvent.

24

Amorphous Precipitations in a Crystalline Carrier: the API is at the

molecular level dispersed in a polymer matrix

Compound or Complex Formation;

Combinations of the previous five types.

25


Solid Dispersion Advantages

Reduced particle size

Improved wettability

Higher porosity

Drugs in amorphous state

26

Solid Dispersion Preparation Method

Fusion method

Hot melt extrusion

Solvent method

Supercritical fluid method

27

Fusion method: The drug was melted in a carrier and after cooling the dry mass

obtained was pulverized and sieved to obtain powder

Hot melt extrusion: The drug/carrier mix is typically processed with a twin-screw

extruder. The drug/carrier mix is simultaneously melted, homogenized and then

extruded

Solvent method: The physical mixture of the drug and carrier is dissolved in a

common solvent, which is evaporated and resulted in formation of solid dispersion.

Supercritical fluid method: It is mostly applied with CO2 , which is used as either

a solvent for drug and matrix or as an anti solvent. In this method the drug and matrix

are dissolved in CO2 and sprayed through a nozzle into an expansion vessel with lower

pressure resulting in immediate formation of particles.

28


Advantages and Disadvantages

Method Advantages Disadvantages

Fusion Short time process

Solvent free

Not suitable for thermally labile drugs

Hot melt

extrusion

Solvent free

Good controlled temperature system

Large scale production available

Not suitable for thermally labile drugs

Carriers without proper thermoplastic

properties can not be used

Solvent Method Short time process Micro to nano-

particulates obtained

Robust process

Large scale production available

Possible solvents residue in the

product

Supercritical

fluid drying

Mild production condition Possible solvent residue in the

product

Solubilizing power of supercritical

fluid (CO2) limited

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DETECTION OF MOLECULAR STRUCTURE IN AMORPHOUS SOLID

DISPERSION.

The properties of a solid dispersion are highly affected by the uniformity of

distribution of the drug in the matrix.

1. Confocal Raman Spectroscopy was used to measure the homogeneity of

the solid mixture.

2. IR or FTIR, can be used to measure the extent of interactions between drug

and matrix.

3. Temperature Modulated Differential Scanning Calorimetry can be used to

assess the degree of mixing of an incorporated drug.

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Solid Dispersion- Characterization

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QUANTIFICATION OF CRYSTALLINITY IN AMORPHOUS SOLID

DISPERSION

Need : To quantify conversion of amorphous form to crystalline during processing/

ageing.

Acceptance Criteria: The method should be able to quantify at least 5% change w.r.t.

API in the formulation.

Challenge : Quantification is difficult due to

a) Dilution effect of excipients

b) Interference of crystalline excipients.

Solid Dispersion- Characterization

QUANTIFICATION OF CRYSTALLINITY IN AMORPHOUS SOLID DISPERSION:

Following techniques are available to quantify crystallinity:

1. Powder X-ray Diffraction

2. Terahertz Pulsed Spectroscopy

3. Raman Spectroscopy

32

Solid Dispersion- Marketed Preparations

Product/Substance Dispersion Polymer or

Carrier

Technology used Company

Gris-PEG ®

(Griseofulvin)

Polyethylene glycol Melt process, exact

process unknown

Novartis

Sproramax capsules

(Itraconazole)

Hydroxypropyl

methylcellulose (HPMC)

Spray layering Janseen

Pharmaceutica

Cesamet® (Nabilone) Providone Process unknown Lilly

Kaletra (Lopinavir and

ritonavir)

Polyvinylpyrolidone

(PVP)/polyvinyl acetate

Melt - extrusion Abbot

Laboratories

Ibuprofen Various Melt - extrusion Soliqs

Isoptin SRE-240

(Verapamil)

Various Melt-extrusion Soliqs

LCP-Tacro (Tracrolimus) HPMC Melt-granulation Life Cycle Pharma

Intelence (Etravirine) HPMC Spray drying Tibotec

Certican (Everolimus) HPMC Melt or spray drying Novartis

Afeditab (Nifedipine) Poloxomer or PVP Melt/absorb on carrier Elan Corp.

33

REGULATORY CHALLENGES

Regulatory Challenges

The emergence of products based on new technologies, posed an urgent

need for the regulatory agencies to develop a comprehensive list of tests and

a streamlined approval process.

Currently, the regulatory agencies examine such drug products on a product-

by-product basis.

There is generally a lack of standards in the examination of products based

on new technologies (Nanocrystals/solid dispersions) as a unique category of

therapeutic agents.

35

A few fundamental and logical questions may help simplify the discussion

around potential regulatory complexity of new technologies products

Physico-chemical characteristics: what are the key characteristics of

the product that are essential for its activity and safety, and are those

critical characteristics of the product reproduced within acceptable

pharmaceutical tolerances in manufacturing?

Definition: does the product meet the criteria of an acceptable,

scientifically sound description or definition (these are still evolving) for

eg. what can be considered a nanomedicine (certain size constraints as

well as unique function)?

36


Biodistribution: are there any particular properties of the product that one

would expect unusual biodistribution or more importantly cause persistence of

the product in particular tissues over extended periods of time, intentionally or

otherwise? If so, what are their effects?

Clinical: what human clinical data should be collected to evaluate potential

safety risks specialy to the nanomedicine, whether acute or on a longer term

basis upon repeated administration?

37


Thus in order to proactively address rapid advances in drug development,

appropriate processes to develop definitions, quality standards, and

requirements for development studies including clinical trial must be in place.

38


Advances in Topical Drug Delivery

Vinod P. Shah, Ph. D.

Consultant, USP

Challenges in BE Evaluation

– Pros and cons of different methods for BE

Standards for topical drug products

– USP <3>, <724> and <1724>

Future steps

– Standardization of DPK methodology

– Explore potential use of In vitro release (IVR)

– Combination techniques for BE – e.g., DPK with

DMD; DPK with IVR; DMD with IVR

Topical Drug Products

Transdermals - For systemic effect

Topical drug delivery - For local action (in

skin)

Topical dosage forms - Generic drugs

– Generic Product: PE + BE = TE = TI

– Topical: Q1 and Q2

– Bioequivalence testing - Challenge

Consider site and mechanism of action

Sensitivity and feasibility of approach

Complexity of the formulation

Case-by-case approach

– In Vitro testing

Topical Dosage Forms

Locally Acting Drug Products

• Methods for BE (identified in 21 CFR 320.24) – Pharmacokinetic study

– Pharmacodynamic study

– Clinical study (comparative clinical trials) and

– In vitro dissolution / release

• A 2003 addition to the Federal FD & C Act at Section

505 (j)(8)(A)(ii) indicates that “For a drug that is not

intended to be absorbed into the bloodstream, the

Secretary may assess bioavailability by scientifically

valid measurements to reflect the rate and extent to

which the active ingredient or therapeutic ingredient

becomes available at the site of drug action”.

Methods of BE of Topical Dermatological Drug Products

Experimental Procedures

Acceptable Promising Unacceptable

Clinical

Pharmacodynamic Suction Blister

Skin Biopsy

Grafted Skin

Surface Recovery

Spectroscopy DPK

Microdialyss

PK

In Vitro

Dermatopharmacokinetics (DPK)

Lessons Learned from US DPK studies

The methodology must be standardized and validated - drug application area - drug / stratum corneum removal area

• In Japan DPK is accepted • DPK is suitable for superficial skin infection

• How to resurrect DPK?

Promising Methodology

In Vitro Methods

• Synthetic Membrane

- QC measure - Can provide supportive data with other promising methods - With Q1 and Q2, can provide information on Q3, and can be used for drug approval*

* Draft Guidance on Acyclovir – March 2012

BE of Topical Drugs - Case-by-Case

• PK approach: Topical patch – Lidocaine 5%

- Lidocaine concentration in plasma – it is proportional

to the concentration at site of action

• PD approach: Flucocinolone acetonide topical oil

-Vasoconstriction . If Q1 and Q2 then biowaiver

• Clinical approach: 5-Flourouracil cream 5%

- Clinical endpoint BE study using actinic keratoses

lesions (100% clearance)

• PK & Clinical approach: Diclofenac sodium gel 1%

• In Vitro approach: Acyclovir Ointment 5%

- If generic and RLD are Q1 and Q2 Q3 (IVR)

- If not Q1 and Q2 clinical end point study

Reasonable test

Batch-to-batch uniformity

QbD emphasizes development of a meaningful

drug development specification based on

clinical performance. IVR is the first step

towards this goal.

To be implemented as a required drug

product release and stability test.

Ref: AAPS Journal, 15 (1), 41-52, 2013.

In vitro Release (IVR) Test

Q1 – Same ingredients/components as RLD

Q2 – Same ingredients/components in the same

concentration as RLD

Q3 – Same ingredients/components/in the same

concentration with same arrangement of matter

(microstructure) as RLD

Acceptable comparative physicochemical characterization

and equivalent in vitro release (Q3) to RLD

Biowaiver may be granted with supportive data to

demonstrate Q1 and Q2 same and similar physicochemical

characteristics (Q3 – IVR)

Ref: AAPS Journal, 15 (1), 41-52, 2013.

Q1, Q2 and Q3. In vitro Release

Product Quality & Product Performance Tests

• Product Quality Test Intended to assess attributes such as identity, strength, purity,

content uniformity, pH, minimum fill, microbial limits.

• Product Performance Test Designed to assess product performance and in many cases

relates to drug release from the dosage form.

• Quality tests assess the integrity of the dosage form, whereas

performance tests assess drug release and other attributes that

relate to in vivo drug performance.

• Taken together, quality and performance tests assure the

identity, strength, quality, and purity of the pharmaceutical

dosage form.

Chapters in USP:

<3> Topical and transdermal drug products –

product quality tests. Official in USP

<724> Drug release (for TDS)

<1724> Semisolid drug products – Performance

test Official in USP36/NF 31, Supplement 1;

Official in August 1, 2013.

Product Quality & Product Performance Test

Strength, efficacy, purity and safety characterization

Qualitative description organoleptic qualities and product

consistency

Visual test of homogenity

Identification

pH potential effects

Variation is specific gravity

Monitoring water content and alcohol content (where applicable)

Container closure system

Preservative

Antioxidants

impurity

Drug Product Quality Tests <3>

Vertical Diffusion Cell System – based on passive

diffusion of the active into the receptor fluid - most

experience, widely used, well studied

Sensitive, reproducible, rugged, robust

Synthetic membrane – support membrane

Medium – aqueous or hydro-alcoholic mixture

Degas the medium, 320

Release rate dependent on formulation composition,

particle size and strength

Release rate is formulation specific (similar to MR

dosage forms)

In Vitro Release <1724>

Semisolid Dosage Forms: Creams, Ointments, Gels

• Method of choice:

Vertical diffusion cell with a synthetic membrane

VDC method is described in USP <1724>

(USP36/NF31, 1st Supplement,

Official August 1, 2013)

• It is a measure of product quality and sameness with

SUPAC related changes.

• With Q1, Q2 and Q3 (in vitro release) the method can be

used for biowaiver of acyclovir ointment

• FDA is advocating use of IVR as a specification for

product release – similar to dissolution

QC tool – batch release test !

Formulation development

Selection of formulation for clinical testing

Product performance assessment

Post approval changes (SUPAC)

Compare with RLD

IVR is a useful tool

Possible application for biowaiver of lower

strength(s)

In Vitro Release

Bioequivalence evaluation – case-by-case

DPK method needs to be standardized and

validated

IVR can be used as a product performance test

Potential application of IVR should be explored

Application of combination techniques should

be explored for generic drug approval

Conclusions

Target Delivery of Injectables

N. Subramanian, M.Pharm., Ph.D.

Agila Specialities Ltd., (Division of Strides Arcolabs Ltd.)

Market Trend of Target delivery Systems

Classification

Design requirements

Liposomal Drug Delivery System

– Manufacturing & Characterization aspects.

Regulatory Viewpoint on Liposomal drug product

Conclusion

Topics Covered

Drug Discovery Timelines

Preclinical

• 1000 Molecules

• 3-6 years

Phase I/II/III

• 25 Molecules

• 6-7 years

Phase IV • 1 Molecule

New Drug to Market

The global market for drug delivery systems in 2010 was $131.6 billion. The market is expected to rise

at a compound annual growth rate (CAGR) of 5% and reach nearly $175.6 billion by 2016.

The U.S. constituted approximately 59% of the total drug delivery market in 2010. It is forecast to grow

from $78 billion in 2010 to $103 billion in 2016.

Drug Delivery System – Global market View

*Source – BCC Research

The largest segment of the market is targeted drug delivery, which reached $50.9 billion in 2009 and

is expected to increase to $80.2 billion in 2014, for a CAGR of 9.5%.

Sustained-release products have the second-largest market share, with estimated sales of $36.1

billion in 2009 and $45.8 billion in 2014, for a CAGR of 4.9%.

Drug Delivery System – Global market View

Global Cancer therapy Market

The global cancer therapy market will increase from $40.0 billion in 2007 to an estimated $110.6 billion in

2013, a compound annual growth rate (CAGR) of 18.5%.

Target therapy dominated in 2007 with a 45% share of the total cancer therapy market. This is expected to

increase to 62.5% in 2013.

Nanocarrier Market Share by Technology in 2021

Liposomes

AU nanocarriers

Dendrimers

Micelles

Polymeric nanocarriers

Nanoshells

Classification of Current Targeted Drug Delivery Processes

1. Systemic targeting based on blood circulation and extravasation

a) Ligand–receptor interaction mediated

b) Locally-activated delivery

i. Self-triggered release of the drug at the target cells

ii. Externally-activated release of the drug at the target cells

2. Intracellular targeting

a) Low-pH activation technologies that use default pathway delivery

to lysosomes

b) Mechanisms that avoid (default) lysosomal delivery

Therapeutic Monoclonal Antibodies in Cancer Therapy

Antibody Drug Conjugates in Cancer Therapy

Target Drug Delivery Systems

Brand Name Structure Type of Drug association

Tocosol Drug solubilized in emulsion

droplets

Abraxane

Drug in Albumin nanoparticles

Genexol Drug in Polymer micelles

Taxol

Drug solubilized in cremophor

micelles

Xyotax Micelle/aggregate of

Drug/Glutamic acid derivative

Ambisome Drug solubilized in lipid bilayer

Drug Targeting Concepts of I.V. Administered Systems

EPR effect

Nanoparticle properties and design

Increased retention in the circulation due to PEGylation

Ligand–receptor type interactions

Design Requirement of Drug Delivery Systems

Route of Administration

Drug Properties

Biocompatibility

Ability to Targeting

Nature of delivery vehicle

Mechanism of drug release

Duration of delivery

GOAL

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Liposomes (Vesicles)

The Technology

• Self assembled, closed systems made of lipids in the form of one or

multiple concentric bilayers capable of delivering hydrophilic/

hydrophobic/ amphiphilic drugs

Key Advantages

• Suitable for delivery of hydrophobic, hydrophilic and amphipatic

drugs and agents

• Chemically and physically well characterized entities

• Biocompatible

• Suitable for controlled release

• Suitable to give localized action in particular tissues.

• Suitable to administer via various routes

• Protect drug from degradation in body

• Reduces side effects

• Improves patient quality of life

Liposomes (Vesicles)

Liposome Forming Material - Phospholipid

- Biodegradable and biocompatible

- Non-immunogenic and component of cell membrane

- Approved by regulatory authorities for pharmaceutical use

Key Features:

76

Classification Based on Size

• Small unilamellar vesicles

• Medium sized unilamellar vesicles

• Large unilamellar vesicles

• Oligolamellar vesicles

• Multilamellar large vesicles

• Multivesicular vesicles

78

Classification Based on Specific Properties

• Conventional liposomes are encaptured by

macrophages

• Stealth liposomes evades this process and

remain long-circulating in the blood.

Conventional and Stealth liposomes

79

Liposome Targeting

Accumulates in tumor through leaky

micro-vasculature of tumor tissue

Retained at site due to insufficient

lymphatic drainage from the tumor

Maintain higher concentration of

liposomal drug in the tumor.

Intact vasculature of heart and healthy

organs prevents drug exposure lowering

the toxicity to cardiac muscle and

healthy organs Lower toxicity and Higher tumor accumulation (EPR effect)

Passive Targeting

The tumor microenvironment contributes to destabilizing the lipid carrier through

the action of the slightly acidic pH of interstitial fluids, the release of lipases from

dying tumor cells, and the release of enzymes and oxidizing agents by tumor

infiltrating inflammatory cells. In addition, phagocytic cells residing in tumors could

metabolize liposomes and release free drug, killing neighboring cells via the

bystander effect.

Drug Release from Liposome into Tumor

Higher concentration of the drug is

therefore maintained inside the tumor by

pegylated liposomes for prolonged period

of time.

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81

Marketed Liposomal Products

Approved Liposome Products in US

Doxil Doxorubicin 1995

Daunoxome Daunorubicin 1996

Ambisome Amphotericin B 1997

Depocyt Cytarabine 1999

First Generic Liposomal Injection approval

Doxorubicin Sun Pharma 2013

liposome inj

82

Steps Involved in Manufacture of Liposomes

• Selection and Analysis of raw materials – Drug, Phospholipids,

cholesterol, buffer etc.

• Optimization of composition of formulation (Drug: lipid).

• Preparation of multilamellar vesicles by Spray drying, ethanol injection,

thin film hydration etc.

• Preparation of unilamellar vesicles by size reduction.

• Drug loading – Active or Passive methods.

• Removal of free drug.

• Sterilization process.

83

Analytical Challenges

Description

Assay

Related substances

pH

Osmolality

Particulate matter

Sterility

Bacterial endotoxin

Absorbance

Transmittance

Fill range

Volume variation

Reconstitution time (lyo products)

Content Uniformity (lyo products)

General Tests

Analytical Challenges

Liposome specific tests Instrument Used

Lipid content HPLC

Phosphorus content ICP

Lyso lipids HPLC

Physical form of drug inside liposome Fluorescence spectroscopy, TEM, SAXS

In vitro drug release study HPLC

In vitro Plasma stability HPLC, LCMS

Internal volume NMR

Phase transition temperature DSC

Particle size and PDI Particle Size Analyzer

Particle Shape and Lamellarity TEM

% Free drug & % encapsulated drug HPLC

Zeta potential Zeta Sizer

85

Total Drug present in the formulation by HPLC, LCMS methods.

Entrapped drug in liposomes by separation process like centrifugation

or by column separation (example – Sephadex) and then quantification.

Free drug (Unentrapped drug) in formulation.

Assay of Drug in Liposomal Products

86

Analysis of Individual lipids present in the formulation like HSPC,

Cholesterol, DSPG, mPEG-DSPE depending on the formulation.

Analysis of the degradation products of the lipids in formulation like Lyso-

PC, which will influence the stability of the formulation.

Cholesterol will determine the rigidity of the bilayer and thereby the drug

release from liposomes

Analysis of the lipids is very critical as the change in composition will alter

the product performance

Lipid Analysis in Liposomal Products

87

Phase transition temperature of the liposomes depends on the

type of lipids used.

This determines the conditions for the formation of the

liposomes, drug loading, in-vitro and in-vivo drug release.

This also determines the stability and storage condition of the

liposomal formulations.

Examples of Phase transition temperatures of lipids:

HSPC – 52° - 55°C

DPPC – 38° - 42°C

DMPC – 18° - 23.2°C

Phase Transition Temperature of Liposomal Products

88

Particle size plays a major role in the success of the performance of the

product.

Particle Size Analysis of Liposomal Drug Products

89

Cryo TEM image of Multilamellar Vesicles Before Size Reduction

90

Cryo TEM image of Multilamellar Vesicles After Size Reduction

91

Cryo TEM Image of Hydrophilic Drug Containing Liposomes

92

Cryo TEM Image of Hydrophobic Drug Containing Liposomes

93

Zeta Potential Analysis of Liposomal Drug Products

The magnitude of the zeta potential gives an indication of the potential stability of

the colloidal system.

If all the particles in suspension have a large negative or positive zeta potential then

they will tend to repel each other and there is no tendency to flocculate. However, if

the particles have low zeta potential values then there is no force to prevent the

particles coming together and flocculate. The general dividing line between stable

and unstable suspensions is generally taken at either +30mV or -30mV.

Generally Particles with zeta potentials more positive than +30mV or more negative

than -30mV are normally considered stable.

In case of pegylated liposomes, the zeta potential is around -10mV. The liposomes

is stable in spite of low zeta potential due to steric hindrance provided by the PEG

layer on the surface of the liposomes.

94

This study is performed to understand the release pattern of drug

from the liposomes when administered in-vivo.

This is performed using dialysis membranes / HLB cartridges

having specific affinity for the free drug.

Selection of media, experimental conditions like pH, temperature,

ionic concentrations play important role in the drug release.

Free drug and entrapped drug are separated after specific time

points and Drug release curve is plotted with respect to time.

Invitro Drug Release of Liposomal Drug Products

95

At the preclinical stage, Sponsors should perform minimum of the following studies:

Single and multiple dose pharmacokinetics, toxicokinetics, and tissue distribution

studies in relevant species.

a) Pharmacokinetic study in tumor bearing mice (in case of anticancer drug) /

normal mice (in case of other drugs) and also in rats.

b) Organ Distribution study in mice and rats.

c) Pharmacokinetic / Toxicokinetic study in higher animal like dog/monkey.

a) Tumor regression study in case of anti cancer drugs (Ex. Doxorubicin)

b) Antifungal activity in case of antifungal agents (Ex. Amphotericin B)

Preclinical Studies of Liposomal Drug Products

Toxicokinetic and Pharmacokinetic Studies:

Efficacy Studies:

FDA’s Draft Guidance on Liposome Drug Products

Draft Guidance

since August 2002

Physicochemical Characterization Requirement

• Description

• morphology of the liposome, including

lamellarity determination, if applicable

• net charge

• volume of entrapment in liposomal

vesicles

• particle size (mean and distribution

profile)

• phase transition temperature

• spectroscopic data, as applicable

• in vitro release of the drug substance

from the liposome drug product

• osmotic properties

• light scattering index

• assay for encapsulated and

unencapsulated (i.e., free) drug

substance

• degradation products related to the lipids

• assay of lipid components

• in vitro test for release of drug substance

from the liposome

Pharmacokinetic and Bioavailability Requirement

• a single-dose pharmacokinetic study; this should be a

comparative study between the liposome and nonliposome

drug product, when appropriate

• a multiple-dose study evaluating the pharmacokinetics of the

drug substance after administration of the liposome drug

product

• a dose-proportionality study over the expected therapeutic

dose range after administration of the liposome drug product

Pharmacopoeial Status

• Indian Pharmacopoeia has published a

chapter on Liposomal products in its 2010

edition

• Also a monograph on Liposomal

Amphotericin B for injection is included in IP.

Guidances for Generic Liposomal Products

• Lipid content

• Free and encapsulated drug

• Internal and total sulfate

• Ammonium concentration

• Histidine concentration

• Sucrose concentration

• State of encapsulated drug

• Form of a doxorubicin sulfate precipitate inside the liposome

• Internal environment (volume, pH, sulfate and ammonium ion concentration)

• Liposome morphology and number of lamellae

• Lipid bilayer phase transitions

• Liposome size distribution

• Grafted PEG at the liposome surface

• Electrical surface potential or charge

Draft Guidance on Doxorubicin Hydrochloride - USFDA

Pharmaceutical Equivalence Tests

Bioequivalence Requirement

1. Bioequivalence Study

In vitro Leakage Under Multiple Conditions

• Lipidic components (description, source and characterisation, manufacture, specification

and stability);

• Quality, purity and stability of other nonlipidic starting materials and critical excipients;

• Identification and control of key intermediates in the manufacturing process;

• Active substance/ lipidic moiety ratio at relevant manufacturing steps to ensure consistent

formulation;

• Liposome morphology, size and size distribution,

• Fraction of encapsulated active substance (amount of free/entrapped)

• Assay of lipidic components;

• Osmolarity;

• Stability of the active substance, lipids and functional excipients in the finished product,

including quantification of critical degradation products (e.g. Lyso phosphatidylcholine,

oxidated/ hydrolytic moieties)

• Stability studies under proposed in-use conditions;

• In vitro drug substance release rate from the liposome in relevant media and stress

conditions;

• Validated process for reconstitution and/or pharmacy preparation


EMEA Reflection Paper

Maintenance of liposomal formulation integrity in plasma;

Characterization/ specification testing for lipid bilayer phase transition; temperature and/or

liposomal ‘surface’ charge;

Confirmation of physical state of the active substance inside the liposome

for pegylated liposomal formulations:

details of linkage chemistry (PEG-lipid),

molecular weight of pegylated lipid and size distribution,

disposition of PEG at surface,

stability of pegylation;

Discriminating validated in-vitro release methods should be developed to:

monitor the simulated release of the active substance from the liposomes when in

circulation and if possible around the targeted site of action (e.g. different pH

environments at site of action).


Non-Clinical and Clinical Studies

Non clinical Studies

Pharmacokinetic studies

o accumulation in target organs, pharmacokinetics and distribution

Pharmacodynamic

o demonstration of similarity in pharmacodynamic response at different dose

levels using adequate models

o in-vitro tests which characterize the interaction between liposomes and

target cells or with other cells where the interaction is toxicologically relevant

and important

Toxicological studies

Clinical Studies

Comparative pharmacokinetic studies

Conclusions

• Target Delivery system expected to grow at a faster phase in the next

decade.

• Better understanding in the manufacturing and characterization of TDS

in the last 2 decades will boost the development of the injectable target

delivery system.

• Availability of various guidance documents and monographs will provide

better clarity of the requirements for development of generic liposomal

dosage form.

• This will help generic manufacturers in bringing generic liposomal

formulation to the market faster thereby enable affordable therapy to

needy patients.

Performance Test for Novel Dosage

Forms

Vinod P. Shah, Ph. D.

Consultant, USP

Taxonomy of Dosage Forms

Novel Dosage Forms

Product Quality and

Product Performance Test

Performance Test for Novel Dosage Forms

– Transdermal Drug Delivery System

– Semisolids: creams, ointments and gels

– Liposomes

Outline

Dosage Form Taxonomy (USP)

111

Route of Administration

Intended site of release

Dosage Form Examples

Dosage Form Quality Tests

Dosage Form Performance

Tests* Parenteral Body tissues

and fluids Injectables, Liposomes, micro and nano particles, implants, stents

<1> <1001>**

Oral Gastro intestinal tract

Tablets and capsules, liquids

<2> <701>, <711>

Topical / Transdermal

Skin Semisolids, TDS

<3> <724>, <1724>

Mucosal (Local or Systemic)

Mouth, eye, ear, rectum, vagina, intra-uterine

Films, tablets, liquids, suspensions, suppositories

<4> <1004>**

Inhalation Nasal cavity, lung

Liquids, aerosols, powders

<5> <601>, <602>, <603>, <604>,

<1601> * CK Brown et. al., FIP/AAPS Workshop Report: Dissolution/in vitro release testing of

novel/special dosage forms. AAPS PharmSci Tech. 12(2): 782-794, 2011

** Under Development

Traditional solid oral dosage forms

dissolution test e.g., tablets, capsules,

suspensions

Novel (non-oral) dosage forms

In vitro release test e.g., transdermal patches,

liposomes, stents, implants

Drug-device eluting dosage forms

Drug elution test

Pharmaceutical Dosage Forms

Orally disintegrating tablets

Chewable tablets

Medicated chewing gum

Suspensions

Suppositories

Transdermal patches

Topical semisolids – cream, ointment, gel

Subcutaneous implants

Injectable microparticulate formulations, Microspheres

Liposomes

Drug eluting stents

Novel Dosage Forms

Product Quality Test

Intended to assess attributes such as identity, strength,

purity, content uniformity, pH, minimum fill, microbial limits.

Product Performance Test

Designed to assess product performance and in many cases

relates to drug release from the dosage form.

Quality tests assess the integrity of the dosage form,

whereas performance tests assess drug release and other

attributes that relate to in vivo drug performance.

Taken together, quality and performance tests assure the

identity, strength, quality, and purity of the pharmaceutical

dosage form.

Product Quality & Product Performance Tests

USP General Chapters <1> through <5> provide

– information about the product quality tests

– a framework to support new individual monographs that are

“moving forward” documents and are not intended to replace the

need for individual monographs.

– a pick list of consolidated common product quality test

requirements in a concise and a coherent fashion.

If a validated performance test procedure is available for the

specific drug product, it is identified in general chapter below

<1000>. Additional information, or information on promising

technologies that have not yet been fully validated, may be

presented in informational chapters above <1000>.

Product Quality Tests

Product quality and performance tests link with

establishment of BA or BE Assessment of

Drug Product Performance – Bioavailability,

Bioequivalence and Dissolution <1090>.

When documentation of BA or BE is less

certain USP Medicines Compendium general

chapter Drug Product Performance <12>

provides information on optimum drug product

performance

Drug Product Performance Test

Why in vitro testing?

It is a product quality test

– As a QC measure

– Drug release as a means of product sameness under SUPAC related changes

It is a product performance test

It is a tool to biopharmaceutics characterization of the product

In Vitro Release: Novel Dosage Forms

Dissolution tests for solid dosage forms are well established

General principles of dissolution test should be applicable to

in vitro release of novel dosage forms -

has been expanded to a variety of novel / special

dosage forms such as TDS (patches), gel, creams, lotions,

ointments, suppositories, injectable microparticulate system,

liposomes, drug eluting stents, implants, aerosols

Due to complexity and drug delivery of novel / special

dosage forms, different apparatus and procedures need to

be employed – on a case-by-case basis.

Concept of In Vitro Testing

• Current compendial apparatus

– - Paddle over disk – USP Apparatus 5

– - Rotating cylinder – USP Apparatus 6

– - Reciprocating disk – USP Apparatus 7

• Method of Choice: Paddle over disk with watch

glass-patch-screen sandwich assembly (Apparatus 5)

• Ensures patch is prevented from floating during test

• pH of the medium ideally 5-6

• Test temperature - 32oC

Unnecessary proliferation of

dissolution equipment should be avoided

Transdermal Patches

Semisolid Dosage Forms: creams, Ointments, Gels

• Method of choice: Vertical diffusion cell with a synthetic membrane

VDC method is described in USP <1724>

(USP36/NF31, 1st Supplement, Official August 1, 2013)

• It is a measure of product quality and sameness with SUPAC

related changes.

• With Q1, Q2 and Q3 (in vitro release) the method can be

used for biowaiver of acyclovir ointment

Drug Release from Microspheres

Risperdal® Consta® 25 mg long acting injection

Manufacturer: McNEIL JANSSEN

API: Risperidone

Route of Administration: Intra-muscular

Indication: Long term treatment of

Schizophrenia

Archana Rawat Ph. D. Thesis 2011. University of Connecticut

Accelerated Release Testing: Risperdal Consta

Microspheres release for:

• ~ 2 days at 54.5°C

• ~ 3 days at 50°C

• ~ 7 days at 45°C

0

0.2

0.4

0.6

0.8

1

0 1 2 3 4 5 6 7 8

Time (Days)

Fra

cti

on

rele

ased

45°C

50°C

54.5°C

Temperature: 45, 50 and 54.5C

Flow rate: 8ml/min

Release medium: Phosphate buffer saline (PBS pH 7.4)


Schizophrenia Research 70 (2004) 91– 100

Plasma Profile Deconvolution: Risperdal® Consta®

0

0.2

0.4

0.6

0.8

1

0 10 20 30 40 50 60 70

Time (Days)

Fra

cti

on

Ab

so

rbe

d

In vivo profile

Plasma profile Deconvoluted plasma profile

Plasma profile deconvolution using Loo-Riegelman method

0

0.2

0.4

0.6

0.8

1

0 2 4 6 8 10Time (Days)

Fra

cti

on

Re

lea

se

d/A

bs

orb

ed

In vivo profile (scaling factor: 7)

In vitro profile (45°C)

0

0.2

0.4

0.6

0.8

1

0 1 2 3 4

Time (Days)

Fra

cti

on

Rele

ase/A

bso

rbed


In vitro profile (50°C)

0

0.2

0.4

0.6

0.8

1

0 0.5 1 1.5 2

Time (Days)

Fra

cti

on

re

lea

se

d/a

bs

orb

ed


In vitro profile (54.5°C)

In Vitro-In Vivo Comparison: Risperdal® Consta®

y = 0.9687x + 0.017

R2 = 0.995

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Fraction Absorbed (In vivo)

Fra

cti

on

Re

lea

se

d (

In v

itro

)


Aerosol Products – MDI and DPI

• Oral inhalation aerosols

• Nasal inhalation aerosols

• Aerodynamic particle size distribution

measured by multistage cascade impactor

• Delivered dose uniformity

Summary

Preferred / Recommended Apparatus

Type of Dosage Form

• Solid oral dosage forms

• Oral suspensions

• Orally disintegrating tablets

• Chewable tablets

• Transdermal patches

• Topicals – Semisolids

• Suppositories

• Medicated gums

• Microparticle formulation

• Implants

Release Method

• Basket or Paddle

• Paddle

• Paddle

• Basket, Paddle,

• Paddle over disk

• Vertical diffusion cell

• Paddle, Modified basket

• Special apparatus

• Modified flow through cell

• Modified flow through cell

Conclusions

• An appropriate drug release test is required to characterize

the drug product and to assure batch-to-batch reproducibility

for consistent in vivo performance

• The in vitro drug release test for some ‘special’ dosage forms

such as semi-solid dosage forms and transdermal drug

delivery systems have proven to be equally valuable as the

dissolution test for solid dosage forms

• The in vitro drug release test shows promise for other

dosage forms such as chewable tablets, suspensions and

suppositories

•For other dosage forms such as chewing gums, powders,

parenterals, further method development and refinement is

needed to make the drug release test a valuable tool

Novel / Special Dosage Forms - Report

FIP/AAPS Joint Workshop Report: Dissolution / In vitro

Release Testing of Novel / Special Dosage Forms: CK Brown, HD Friedel, AR Barker, LF Buhse, S Keitel, TL Cecil, J

Kraemer, JM Morris, C Reppas, MP Sticklemeyer, C Yomota, VP

Shah.

- AAPS PharmSciTech: Vol 12, Issue 2, 782-794, 2011 - Dissolution Technologies: Vol 18 (4), 51-64, 2011. - Die Pharmazeutische Industrie:

- Indian J of Pharm Sci: 73(3), 338-353, 2011.

FIP/RPSGB Workshop in London – October 20-21, 2008

AAPS/FIP Workshop in Los Angeles – November 7-8, 2009

usp chemical medicines & excipients-consideration of novel formulations

Health & Medicine