Usp chemical medicines & excipients-consideration of novel formulations


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12th USP Science & Standards Symposium - New Delhi

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Usp chemical medicines & excipients-consideration of novel formulations

  1. 1. Track I, Session II: Chemical Medicines and ExcipientsConsideration 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
  2. 2. Moderator: Albinus D’Sa, Ph.D. US Food and Drug Administration-India
  3. 3. Solid Oral Formulations Advances Dr. Sukhjeet Panacea Biotec
  4. 4. Solid Oral Formulation Advances  During the past biopharmaceutics, three decades, pharmacokinetics due and to the evolving discipline pharmacodynamics, of 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
  6. 6. Solid Oral Formulation Advances Bioavailability Enhancement of Poorly Soluble Drugs  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. 6
  7. 7. Solid Oral Formulation Advances Bioavailability Enhancement of Poorly Soluble Drugs  Nanocrystals  Solid Dispersion 7
  9. 9. 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. 10. Nanocrystals Source : Nanotechnology in Ireland: A Snapshot 10
  11. 11. 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 11
  12. 12. Case Study – Effect of particle size Comparative PK Profile of Immunosuppressant in animals Concentration (ng/ml) 20 Pharmacokinetic Profile Comparison 15 Coarse API~10microns Micronized API~1.5microns Drug in Solution Nanoparticulate API~less than 1microns 10 5 0 0 4 8 12 16 20 (hr) Time 24 28 32 36 40 44 48 Animal PK study Results – Statistical Analysis PK Parameter AUC(0-t) (hr*ng/ml) Coarse API~10microns Micronized API~1.5microns Nanoparticulate API~less than 1microns Drug in Solution 194.66 494.08 1391.20 976.86 12
  13. 13. 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 Invega Sustenna® Paliperidone palimtate Treatment of schizophrenia 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 First Horizon Pharmaceuticals Johnson and Johnson marketed marketed 13
  14. 14. Nanocrystals Preparation Methods  Precipitation (Bottom up)  Milling (Top down)  Homogenization (Top down)  Top down and Bottom up 14
  15. 15. Nanocrystals Preparation Methods  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
  16. 16. Nanocrystals Preparation Methods  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, IDDP™ 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
  17. 17. Nanocrystals Preparation Methods Advantages and disadvantages Technology Precipitation Milling Homogenization Advantages Disadvantages •- 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) •- 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 •- universally applicable •- high energy technique •- no problem with large batches •- great experience needed •- fast method (several minutes possibly) 17
  18. 18. Nanocrystals- Characterization Characterization technique for drug Nanocrystals Analytical purpose Structural analysis Analytical techniques Conclusion from the results Optical microscopy Size distribution, flocculation tendency, detection of large particles, SEM, TEM, AFM surface morphology of bulk and single BET particles, Porosity, surface area Solid state analysis DSC, PXRD, Raman spectroscopy, Amorphous content, polymorphism IR spectroscopy, Hot stage microscopy Particle size analysis Laser Diffraction , Dynamic light Size and size distribution scattering, coulter counter Surface charge characteristics laser Doppler anemometry (Zeta Agglomeration tendency potential), Capillary Zone stability prediction electrophoresis Rheological assessment Rheometer (Cone and plate, Viscosity rotational cylinder 18
  19. 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 19
  21. 21. 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 21
  22. 22. Solid Dispersion Conventional Dispersion Pharmacokinetic profile of tacrolimus in animal model. 22
  23. 23. 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
  24. 24. Solid Dispersion Classification  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
  25. 25. Solid Dispersion Classification  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
  26. 26. Solid Dispersion Advantages  Reduced particle size  Improved wettability  Higher porosity  Drugs in amorphous state 26
  27. 27. Solid Dispersion Preparation Method  Fusion method  Hot melt extrusion  Solvent method  Supercritical fluid method 27
  28. 28. Solid Dispersion Preparation Method  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
  29. 29. Solid Dispersion Preparation Method Advantages and Disadvantages Method Advantages Disadvantages Hot melt extrusion Solvent Method Supercritical fluid drying      Short time process Solvent free Solvent free Good controlled temperature system Large scale production available  Not suitable for thermally labile drugs   Not suitable for thermally labile drugs Carriers without proper thermoplastic properties can not be used  Short time process Micro to nanoparticulates obtained Robust process Large scale production available    Fusion Possible solvents residue in the product  Mild production condition  Possible solvent residue in the product Solubilizing power of supercritical fluid (CO2) limited  29
  30. 30. Solid Dispersion- Characterization  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. 30
  31. 31. 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. 31
  32. 32. 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
  33. 33. Solid Dispersion- Marketed Preparations Product/Substance Dispersion Polymer or Technology used Company Carrier Gris-PEG ® Polyethylene glycol (Griseofulvin) Melt process, exact Novartis process unknown Sproramax capsules Hydroxypropyl Spray layering Janseen (Itraconazole) methylcellulose (HPMC) Cesamet® (Nabilone) Providone Process unknown Lilly Kaletra (Lopinavir and Polyvinylpyrolidone Melt - extrusion Abbot ritonavir) (PVP)/polyvinyl acetate Ibuprofen Various Melt - extrusion Soliqs Isoptin SRE-240 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. Pharmaceutica Laboratories (Verapamil) 33
  35. 35. 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 productby-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
  36. 36. Regulatory Challenges  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
  37. 37. Regulatory Challenges  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
  38. 38. Regulatory Challenges  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
  39. 39. Advances in Topical Drug Delivery Vinod P. Shah, Ph. D. Consultant, USP
  40. 40. Topical Drug Products  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
  41. 41. Topical Dosage Forms  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
  42. 42. 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”.
  43. 43. Methods of BE of Topical Dermatological Drug Products Experimental Procedures Acceptable Promising Clinical DPK Pharmacodynamic Microdialyss Unacceptable Spectroscopy Suction Blister PK In Vitro Skin Biopsy Grafted Skin Surface Recovery
  44. 44. 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?
  45. 45. 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
  46. 46. 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
  47. 47. In vitro Release (IVR) Test  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.
  48. 48. Q1, Q2 and Q3. In vitro Release  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.
  49. 49. 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.
  50. 50. Product Quality & Product Performance Test 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.
  51. 51. Drug Product Quality Tests <3>  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
  52. 52. In Vitro Release <1724>  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)
  53. 53. 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
  54. 54. In Vitro Release  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)
  55. 55. Conclusions  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
  56. 56. Target Delivery of Injectables N. Subramanian, M.Pharm., Ph.D. Agila Specialities Ltd., (Division of Strides Arcolabs Ltd.)
  57. 57. Topics Covered  Market Trend of Target delivery Systems  Classification  Design requirements  Liposomal Drug Delivery System – Manufacturing & Characterization aspects.  Regulatory Viewpoint on Liposomal drug product  Conclusion
  58. 58. Drug Discovery Timelines Preclinical Phase I/II/III Phase IV • 1000 Molecules • 3-6 years • 25 Molecules • 6-7 years • 1 Molecule New Drug to Market
  59. 59. Drug Delivery System – Global market View  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. *Source – BCC Research
  60. 60. Drug Delivery System – Global market View  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%.
  61. 61. 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.
  62. 62. Nanocarrier Market Share by Technology in 2021 Nanoshells Polymeric nanocarriers Liposomes Micelles Dendrimers AU nanocarriers
  63. 63. 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
  64. 64. Therapeutic Monoclonal Antibodies in Cancer Therapy
  65. 65. Antibody Drug Conjugates in Cancer Therapy
  66. 66. 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
  67. 67. 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
  68. 68. Design Requirement of Drug Delivery Systems Route of Administration Duration of delivery Drug Properties GOAL Mechanism of drug release Biocompatibility Nature of delivery vehicle Ability to Targeting
  69. 69. Liposomes (Vesicles) The Technology • Self assembled, closed systems made of lipids in the form of one or multiple concentric bilayers capable hydrophobic/ amphiphilic drugs of delivering hydrophilic/ 74
  70. 70. Liposomes (Vesicles) 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
  71. 71. Liposome Forming Material - Phospholipid Key Features: - Biodegradable and biocompatible - Non-immunogenic and component of cell membrane - Approved by regulatory authorities for pharmaceutical use 76
  72. 72. Classification Based on Size • Small unilamellar vesicles • Medium sized unilamellar vesicles • Large unilamellar vesicles • Oligolamellar vesicles • Multilamellar large vesicles • Multivesicular vesicles
  73. 73. Classification Based on Specific Properties Conventional and Stealth liposomes • Conventional liposomes are encaptured by macrophages • Stealth liposomes evades this process and remain long-circulating in the blood. 78
  74. 74. Liposome Targeting Passive 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) 79
  75. 75. Drug Release from Liposome into Tumor 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. Higher concentration of the drug is therefore maintained inside the tumor by pegylated liposomes for prolonged period of time. 80
  76. 76. 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 81
  77. 77. 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. 82
  78. 78. Analytical Challenges General Tests 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) 83
  79. 79. 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
  80. 80. Assay of Drug in Liposomal Products  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. 85
  81. 81. Lipid Analysis in Liposomal Products  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 LysoPC, 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 86
  82. 82. Phase Transition Temperature of Liposomal Products  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 87
  83. 83. Particle Size Analysis of Liposomal Drug Products  Particle size plays a major role in the success of the performance of the product. 88
  84. 84. Cryo TEM image of Multilamellar Vesicles Before Size Reduction 89
  85. 85. Cryo TEM image of Multilamellar Vesicles After Size Reduction 90
  86. 86. Cryo TEM Image of Hydrophilic Drug Containing Liposomes 91
  87. 87. Cryo TEM Image of Hydrophobic Drug Containing Liposomes 92
  88. 88. 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. 93
  89. 89. Invitro Drug Release of Liposomal Drug Products  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. 94
  90. 90. Preclinical Studies of Liposomal Drug Products At the preclinical stage, Sponsors should perform minimum of the following studies: Toxicokinetic and Pharmacokinetic 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. Efficacy Studies: a) Tumor regression study in case of anti cancer drugs (Ex. Doxorubicin) b) Antifungal activity in case of antifungal agents (Ex. Amphotericin B) 95
  91. 91. FDA’s Draft Guidance on Liposome Drug Products Draft Guidance since August 2002
  92. 92. Physicochemical Characterization Requirement • Description • • morphology of the liposome, including unencapsulated (i.e., free) drug lamellarity determination, if applicable substance assay for encapsulated and • net charge • degradation products related to the lipids • volume of entrapment in liposomal • assay of lipid components vesicles • in vitro test for release of drug substance • 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 from the liposome
  93. 93. 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
  94. 94. 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.
  95. 95. Guidances for Generic Liposomal Products
  96. 96. Pharmaceutical Equivalence Tests Draft Guidance on Doxorubicin Hydrochloride - USFDA • • • • • • • • • • • • • • 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
  97. 97. Bioequivalence Requirement 1. Bioequivalence Study
  98. 98. In vitro Leakage Under Multiple Conditions
  99. 99. Pharmaceutical Equivalence Tests EMEA Reflection Paper • • • • • • • • • • • • 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
  100. 100. Pharmaceutical Equivalence Tests  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).
  101. 101. 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
  102. 102. 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.
  103. 103. Performance Test for Novel Dosage Forms Vinod P. Shah, Ph. D. Consultant, USP
  104. 104. Outline  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
  105. 105. Dosage Form Taxonomy (USP) Route of Intended site Administration of release Dosage Form Examples Dosage Form Dosage Form Quality Tests Performance Tests* Parenteral Body tissues and fluids Injectables, Liposomes, micro and nano particles, implants, stents <1> <1001>** Oral Gastro intestinal Tablets and capsules, tract liquids <2> <701>, <711> Topical / Skin Transdermal Mucosal Mouth, eye, ear, (Local or Systemic) rectum, vagina, intra-uterine Semisolids, TDS <3> <724>, <1724> Films, tablets, liquids, suspensions, suppositories <4> <1004>** Inhalation Liquids, aerosols, powders <5> <601>, <602>, <603>, <604>, <1601> Nasal cavity, lung * 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 111
  106. 106. Pharmaceutical Dosage Forms  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
  107. 107. Novel 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
  108. 108. 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.
  109. 109. Product Quality 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>.
  110. 110. Drug Product Performance Test  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
  111. 111. In Vitro Release: Novel Dosage Forms  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
  112. 112. Concept of In Vitro Testing  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.
  113. 113. Transdermal Patches • Current compendial apparatus – - Paddle over disk – USP Apparatus 5 – - Rotating cylinder – USP Apparatus 6 – - Reciprocating disk – USP Apparatus 7 • • Ensures patch is prevented from floating during test • pH of the medium ideally 5-6 •  Method of Choice: Paddle over disk with watch glass-patch-screen sandwich assembly (Apparatus 5) Test temperature - 32oC Unnecessary proliferation of dissolution equipment should be avoided
  114. 114. 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
  115. 115. 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
  116. 116. Accelerated Release Testing: Risperdal Consta Temperature: Flow rate: Release medium: 45, 50 and 54.5C 8ml/min Phosphate buffer saline (PBS pH 7.4) Fraction released 1 0.8 0.6 45°C 0.4 50°C 0.2 54.5°C 0 0 1 2 3 4 5 6 7 8 Time (Days)  Microspheres release for: • ~ 2 days at 54.5°C • ~ 3 days at 50°C • ~ 7 days at 45°C Archana Rawat Ph. D. Thesis 2011. University of Connecticut
  117. 117. Plasma Profile Deconvolution: Risperdal® Consta® Plasma profile Deconvoluted plasma profile Fraction Absorbed 1 0.8 In vivo profile 0.6 0.4 0.2 0 0 10 20 30 40 50 Time (Days)  Plasma profile deconvolution using Loo-Riegelman method Schizophrenia Research 70 (2004) 91– 100 60 70
  118. 118. In Vitro-In Vivo Comparison: Risperdal® Consta® In vivo profile (scaling factor: 7) 1 In vivo profile (scaling factor: 19) In vitro profile (45°C) 0.8 Fraction Release/Absorbed Fraction Released/Absorbed 1 0.6 0.4 0.2 0 0.8 In vitro profile (50°C) 0.6 0.4 0.2 0 0 2 4 6 8 10 0 1 2 Time (Days) 4 1 0.8 0.6 0.4 In vivo profile (scaling factor: 39) In vitro profile (54.5°C) 0.2 Fraction Released (In vitro) 1 Fraction released/absorbed 3 Tim e (Days) 0.8 y = 0.9687x + 0.017 R2 = 0.995 0.6 0.4 0.2 0 0 0 0.5 1 Time (Days) 1.5 2 0 0.2 0.4 0.6 Fraction Absorbed (In vivo) Archana Rawat Ph. D. Thesis 2011. University of Connecticut 0.8 1
  119. 119. Aerosol Products – MDI and DPI • Oral inhalation aerosols • Nasal inhalation aerosols • Aerodynamic particle size distribution measured by multistage cascade impactor • Delivered dose uniformity
  120. 120. 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
  121. 121. 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
  122. 122. 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