Presentation on theme: "1 Particle Processing and Modeling in the Pharmaceutical Industry B. J. Glasser Department of Chemical and Biochemical Engineering Rutgers University Piscataway,"— Presentation transcript:
1 Particle Processing and Modeling in the Pharmaceutical Industry B. J. Glasser Department of Chemical and Biochemical Engineering Rutgers University Piscataway, New Jersey 08854
2 Drug A drug product consists of therapeutics and excipients combined in a delivery system. A drug product’s success lies in its ability to deliver the drug at a certain rate in a certain environment in the body. DiscoveryDeliveryManufacture /images/epothilone_anticanc er_compound.jpg /benephit.jpg
3 Regulations “FDA’s responsibility is to protect the American public. In terms of products that are developed by a technology--whether it's a new technology or a conventional technology--our role is to ensure that the products are safe. Our role is not really to make a judgment about whether they should be placed in the marketplace or not.... We are here as the gatekeeper to close the gate if a product is not going to be safe for consumers.... “ GMP regulations address issues including record keeping, personnel qualifications, sanitation, cleanliness, equipment verification, process validation, and complaint handling.
4 Growth of Pharmaceutical Industry in USA US Sales
5 World Pharmaceutical Market
6 Comparison of Annual Sales Per Person ANNUAL SALES PER PERSON OF PHARMACEUTICALS (2004, £ )
7 Growth of Pharmaceutical R&D Expenditure
8 Comparison of Pharmaceutical R&D WORLD VOLUME OF PHARMACEUTICAL R&D (2004 £m)
9 Employment by Establishments Total: employees in USA
10 Pharmaceutical Employment by Position Level Occupation Employment, 2004 Num berPercent Total, all occupations Management, business, and financial occupations Professional and related occupations Office and administrative support occupations Production occupations Sales and related occupations 9 3 Installation, maintenance, and repair occupations Transportation and material moving occupations Others 5 2
11 New Drug Discovery scovery.jpg humbs/nbt F1.jpg
12 Dosage Forms Tablets/Capsules ages/c_rx-capsule.jpg Injectables /injectable.jpg Inhalants /pr/releases/images/v ectura-inhale.gif tech.com/pm/nb1app3. jpg Transdermal products and implants Skin Drug
13 Types of Tablets (>80% of Total Products) Compressed tablets – Multiple compressed tablets Sugar - Coated tablets Film - Coated tablets – Enteric coated tablets Buccal or sublingual tablets Chewable tablets Effervescent tablets Hypodermic tablets Advantages convenience of consumptiom shelf-life (stability) economics of manufacturing patient acceptance
14 Product/Process Development Paradigm Adjusted particle properties Preliminary process (unknown manufacturability) Drug is converted into Particles (sub-optimal delivery properties) Drug Synthesis Raw Chemicals Formulation Process Development & Scale up Adjusted process (unknownscalability ) Manufacturing Product
15 Pharmaceutical Engineering Around 15 years to bring a new drug to market Blockbuster drug - $1B annual sales Product development and scale-up Hiring of chemical engineers Muzzio, Shinbrot, & Glasser, “Powder Technology in the Pharmaceutical Industry: The Need to Catch Up Fast”, Powder Tech., 124,1-7, (2002). Glasser, Cole & Muzzio, “Pharmaceutical Engineering Training”, Pharmaceutical Technology, 25:12, 34-36, (2001).
16 Flow Sheet for Tablet Manufacture Source: F. Muzzio
17 Synthesis Improvement in organic synthesis allow us to make larger and larger molecules.
18 Crystallization Spheres Needles Cubes
19 Agitated Drying of Crystals Crystal Size Distribution: Attrition decreases the size. Agglomeration increases the size. Lekhal et al. Powder Technology (2003) Drying Parameters: Drying Temperature Agitation Speed Drying time Vacuum
20 Drying Freeze Drying Spray Drying solvent evaporation Spray drying consists of the following unit operations: Pre-concentration of liquid Atomization (creation of droplets) Drying in stream of hot, dry gas (usually air) Separation of powder from moist gas Cooling Packaging of product
21 Milling and Granulation Create a desired particle size Improve flow and handling Increase flow rate Increase uniformity in finished product Increase density -reduce volume required for processing and storage -Increase batch size Reductions in dust Improve appearance Decrease ingredient segregation Can improve dissolution (surfactant effects) Three Main Granulation Mechanisms
22 Milling/Granulation Equipment A Pulva mill is used for fine grinding of dry or wet materials ranging from 180 microns (80 U.S mesh) to 45 microns (200 U.S. mesh). High shear granulators use both an impeller to provide vigorous mechanical agitation and a chopper to break large agglomerates and promote the growth of small ones. Typically, they produce hard granules less than 2 mm in size.
23 Blending Three main mechanisms for mixing (J.C. Williams) Convection Driven by bulk flow Fast macromixing Easy to scale up Limited by segregated flow structures (incomplete mixing) Dispersion Driven by individual particle motion Always slow Leads to complete macroscopic homogeneity Scale-up criteria unknown Shear Caused by velocity gradients Required for micromixingof cohesive systems Scale-up criteria unknown
24 Powder Blenders Source: F. Muzzio
25 Problems in Mixing - Segregation Segregation occurs if particles differ in size, density, shape, or other characteristics. Source: F. Muzzio
26 Fluidized Bed Drying * Kunii and Levenspiel, 1991 V o : fluid velocity u t : particle terminal velocity V Om : minimum fluidization velocity
27 Blending Drying Spray-drying Granulation Coating Pelletizing Adsorption High mass and heat transfer Billions of dollars on fluidized bed processes each year Application of FBs in Pharmaceutical Industry
28 Classification of Gas-Fluidized Beds
29 Problems in Fluidized Bed Processing Bubbling Uniform expansion Clustering Streamer Packed bed Increasing Gas Flows Different Flow Regimes Flow Instability Voidage Waves Drying or Reaction Rate Selectivity Product Yield Safety Environmental Impact
30 Tableting Compaction Mechanism Particle re-arrangement (low pressure densification). Particles move into closer packing, air leaves the powder plug. Spherical particles move less than irregularly shaped particles Deformation occurs as pressure is increased, enlarging the area of contact between particles Fragmentation, which gives high yield stress, occurs next as pressure increases. New surfaces and bonding points are created Bond formation then takes place between previously existing and newly created surfaces
31 Tableting Machines Four main stages for tableting : Die fill, weight adjustment, compression, and ejection Rotary tablet presses
32 Problems in Tableting
33 Coating There are several types of coating method that are divided into two main categories: the single layer and the multi-layer coating methods. The first category is most commonly used for the pharmaceutical patches Some of the main variables involved in the selection of the appropriate method are: The number of layers Layer thickness Viscosity Solids content Accuracy Solvent systems Surface treatment and so on
34 Coating Equipment The surface profile of a drug- eluting coating on a stent examined with an optical interferometer reveals some waviness in the coating, along with a lower region in the middle of the area examined Talwar Pharma manufactures a wide range of pellet products, mainly omeprazole and lansoprazole pellets, and offers stage wise quality tests at drug coating stage, sub-coating stage and enteric coating stage technology.com/contractor_images/ta lwar/3.jpg
35 Sampling Accurate sampling is a key technical need for quality control and process characterization In pharmaceutical manufacturing, batch sampling is increasingly becoming a regulatory expectation Standard tools (thief probes) are extremely unreliable, often resulting in samples of uncertain size and composition Random Mixtures (Normal Distributions) Unperturbed Sampling (no thief error) Unchanging Mixtures (no segregation) Stratified Sampling Three Assumptions Source: F. Muzzio
36 Sampling Machines Cavities can be filled with solid dies Only lower cavity used Globe-Pharma Sampler
37 Challenges in Pharmaceutical Industry Development cost is rising – 50% increase in five years Why is this happening? –New drugs are harder to formulate –Products are increasing in complexity –“Regulation is inefficient” Source: F. Muzzio Health care cost is rising rapidly Uninsured, underinsured, and third world populations cannot afford many new drugs Many drugs do not get developed because the economic incentive is not there Number of new drugs has decreased 50% in 10 years
38 The Barriers – and the Opportunity Three inter-related barriers –Lack of synergy between fundamental science and domain knowledge –Lack of predictive models –Lack of the properly trained human resource A major opportunity –Develop the predictive science –Create inter-disciplinary training programs –Provide a forum for science-based regulation Source: F. Muzzio
– Imagine if …… Product development only took six months Cost of development and manufacturing could be cut in half Products and processes could be designed in the computer (like airplanes, microchips) Regulation promoted continuous improvement Pharmaceutical manufacturing was Mature Portable Highly reliable (2.5s 6s) Could manufacture finished pharmaceuticals in a compact device, such as a modified ink-jet printer? –Greatly reduced facilities cost –Reduced batch size and stock –Personalized dosage based on weight –Scalable, flexible Source: F. Muzzio
40 Significance of Particle Processes Essential for 60% of manufactured products Numerous, recurring industrial problems –40-50% operations below design specifications –Commissioning delays & productivity delays –No strong theoretical design basis –Design strategies are usually empirical Erratic flow and inhomogeneity Bridgwater, Gran. Matt., 2002 Knowlton, et al Chem Eng. Prog., 1994 FDC, The Gold Sheet, 2002 Wall Street Journal, 2003 Acute for pharmaceutical industry –80% of drug products are capsules, pills or tablets –18% FDA recalls for “potency/content uniformity” –Uncertain, rudimentary scale-up –Manufacturing efficiency lags other industries
41 Granular Materials Not Yet Understood Extreme behavioral regimes Makse et al, Nature 1995 Umbanhowar et al, Nature 1996 Jenike and Johanssen, 2004 GEA Buck, Inc., 2004 Curious phenomena Scale-gap between particle-level and macroscopic models Michaels, Powhder Tech., 2003
43 Segregation in Granular Materials Treated as unpredictable, inevitable Dominated by rules-of- thumb Breau et al, Phys. Rev. Lett., 2003 Alexander, Muzzio, Shinbrot, Chem. Eng Sci 2003 Broad application hampered: –Numerous qualitative mechanisms –Little agreement, eg. Brazil nut effect
44 Granular Flows in Different Geometries Goldfarb, Glasser and Shinbrot, Nature, (2002) Conway, Shinbrot and Glasser, Nature, (2004) Conway, Lekhal, Glasser, Khinast AIChE J. (2006) Liss, Conway, Zega, and Glasser, Pharmaceutical Technology, (2004) Dry Solids Wet Solids Lekhal, Conway, Glasser, Khinast Chem. Eng. Sci. (2006)
45 Introduction to Nanoparticles Nanoparticles are ultra fine powders whose particle sizes are in the range of nm. Applications in materials and manufacturing, health care, medicine, electronics, environment, energy, chemical and pharmaceutical biotechnology, agriculture, information technology. Nanoparticles in the range of 1-5 nm have potential applications in nanoscale electronics. Nanoparticles below 5 nm exhibit unique physical and chemical properties. %20cells.jpg
46 Contd.. Introduction to Nanoparticles Difference in the range of structural chemistries between bulk and nanoscale particles make nanoparticles unique in vast applications. Properties of nanoparticles vary considerably with size Activity and selectivity can be greatly influenced by nanoparticles. Particle size is critical in determining the properties of nanoparticles. Synthesis of nanomaterials over a range of chemical composition and sizes has been a challenge. An ordered geometry and structure is of interest in nanoparticles (control of shape, size and structure). Spherical nanoparticles were of interest due to their high surface area. Due to high surface area, metal oxide nanoparticles have wide range of applications in sensors, catalysis and electronics.
47 Drug Nanoparticles In pharmaceutics, active ingredient is in the form of solid particles. Application of nanotechnology for treatment, diagnosis, monitoring, and control of biological systems has been determined by NIH as nanomedicine. Drug nanoparticles can be used with the development of nanotechnology. For example, in 2005, FDA approved 130 nm albumin nanoparticles loaded with paclitaxel. Several polymeric, metal nanoparticles, liposomes, micelles, quantum dots, dendrimers, microcapsules, cells, cell ghosts, lipoproteins, and many different nanoassemblies play a major role in diagnosis and therapy. Nanoparticulate pharmaceutical carriers enhance the vivo efficiency of many drugs
48 Importance of Nanosize in Drug Delivery Ref: Gupta R.B, Kompella U.B, Nanoparticle Technology for Drug Delivery, Drugs and Pharmaceutical Sciences. 2006; 159: 2-3.
49 Cond.. Importance of Nanosize Size matching is important for drug delivery. Drug delivery aimed at influencing the biochemistry of the body. Nanoparticles are of great interest in drug delivery due to comparable sizes to the human cells. Biological systems are in the nanometer range To treat the disease, one needs to use the same nanoscale. For example correcting faulty gene, killing leprosy bacteria in the blood cells, blocking multiplication of viral genome, killing cancer cell, repair cellular metabolism etc.
50 Importance of Nanoparticle Surface Ref: Gupta R.B, Kompella U.B, Nanoparticle Technology for Drug Delivery, Drugs and Pharmaceutical Sciences. 2006; 159: 3-4.
51 Cond.. Importance of Nanoparticle Surface (Gupta et.al, 2006) Small size nanoparticles are suitable for variety of drug delivery applications. As the particle size decreases, number of molecules present on particle surface increases. Increased contact area can increase adhesion For spherical solid particle of diameter d, surface area per unit mass, S g, is
52 Nanoparticle Flow for Drug Delivery Nanoparticle flow can be facilitated by –Convective flow induced by the flow of blood, lymph or interstitial fluid –Influence of the interaction of nanoparticles with themselves or with biological components –Diffusion and particle movement of particle suspensions in interstitial tissue Advantages of nanoparticle flow –Small dimension allows them to interact more effectively with cells –Can be safely injected –Diffuse further into tissues –Diffuse through individual cells Larger particles are vulnerable to detachment by shear forces