Application of Supercritical Fluids for improving the dissolution rate of poorly soluble drugs

Size: px

Start display at page:

Download "Application of Supercritical Fluids for improving the dissolution rate of poorly soluble drugs"

Earl O’Brien’
8 years ago
Views:

1 Application of Supercritical Fluids for improving the dissolution rate of poorly soluble drugs Ruggero Bettini Department of Pharmacy Interdepartmental Centre for Innovation in Heath Products, Biopharmanet-TEC University of Parma, Italy Novara, April 11, 2014

2 Poorly soluble API in modern pharmaceutics Growing number of new API (at least 40%) with low aqueous solubility but high therapeutic efficacy Non linear PK Limited and erratic BA Limited dosability in liquid forms Lifecycle management of already marked API 2

3 Why poorly soluble drugs? Drug-like structure for optimisation of specific binding sites Large number of candidates with large MW due to lots of substitutions Reduction of number of new compound in the pipelines

4 Solubility (dissolution rate) enhancement Particle reduction Salt formation Solid dispersion complexation Crystal engineering Physico-chemical modification

5 Biopharmaceutical challenges associated with poorly soluble API Crystal structure & API solubility For BCS class II and IV drugs changes in physico-chemical properties potentially would lead to better oral bioavailability Different administration route

6 Tailored solid state characteristics Particle size Particle shape Particle porosity Surface properties Crystalline purity Crystal habit 6

7 Challenging regulatory issues in medicine production QbD - ICH Q8 PAT Quality Risk management - ICH Q9 Pharmaceutical quality system - ICH Q10 Strong need for process simplification, control and understanding 7

8 Process simplification by SCF Solvent + drug Crystallization Harvesting Drying Sieving Milling (Solvent) + drug +SCF Micron-sized powder 8

9 Pressure (bar) Supercritical Fluid as Reaction Media for Pharmaceutical Processes 140 Supercritical region 120 Liquid Solid Ridge 60 Critical point Triple point Gas Temperature ( C) 9

10 CO 2 isothermal density curves Calculated with Refprop, NIST

11 Particles formation using SCF Supercritical fluid as a solvent:. Rapid Expansion Supercritical Solution (RESS) Supercritical fluid as an antisolvent:. Supercritical Antisolvent Crystallization (SAS). Solution Enhanced Dispersion by Supercritical Fluids (SEDS) Supercritical fluid as an expanding /plasticizing agent Precipitation from a gas saturated solution (PGSS) Supercritical-assisted atomization (SAA; CAN-BD) Variasol 11

Still a cool topic Solubility study of tadalafil solid dispersions obtained by antisolvent precipitation K. Włodarski, W. Sawicki, &. Wojnarowska and M.

12 Still a cool topic Solubility study of tadalafil solid dispersions obtained by antisolvent precipitation K. Włodarski, W. Sawicki, &. Wojnarowska and M. Paluch Supercritical Carbon Dioxide Assisted Melt Extrusion for Forming Homogeneous Drug Dispersion G. Marosi, T. Vigh, Z. Nagy, M. Sauceau, E. Rodier and J. Fages Simultaneous Micronization and Cocrystallization of Ibuprofen by Rapid Expansion of Supercritical Solutions (RESS) K. Mu llers and M. Wahl Strategies to enhance bioavailability of active compounds through supercritical fluid technology The hybrid approach C. Duarte

14 Pluronic F127 L64 solid dispersion

17 Crystals and particles formation with supercritical CO 2 Traditional crystallization processes operational constraints: temperature range cooling rate solute concentration (progressive separation of solid phases) SC CO 2 processes peculiar process conditions: pressure and/or temperature variation rate of solvent evaporation flexibility in operation parameters fine tuning of the density and the solvent (modulating temperature and pressure) 17

18 RESS Meeting of the Royal Society (London 1879) : «We have the phenomenon of a solid dissolving in a gas, and when the solid is precipitated by reducing the pressure, it is brought down as a 'snow' in the gas» Hannay and Hogarth Krukonis, 1984

19 Acetylsalicylic acid by RESS ASA raw material ASA 50 C, 200 bar Reduction of particle size linearly correlated with the pressure No influence of temperature on particle size 19

20 ASA particle size vs pressure Untreated ASA dv (0.5) = 520 µm

21 Drug dissolution Noyes-Whitney equation dm dt DA ( C s - C ) t = h Particle size & crystal habit Solid phase

22 Acetylsalicylic acid by RESS Melting point depression PXRD ASA raw material 50 C, 200 bar

23 Acetylsalicylic acid by RESS Melting temperature decreases linearly correlated with the reciprocal of the mean particles radius. Gibbs-Duhem-Laplace equation: K T e = - + R p T f T e melting temperature treated ASA R p Particle radius T f melting temperature untreated ASA K function of melting entropy, molar volume surface tension.

24 Particles formation with SF as an antisolvent RESSS attractive, simple and relatively easy to implement on a small scale when a single nozzle is used. Low solubility of pharmaceutical product (solvent polarity issue) Decrease of the solvent power by addition of a second fluid (SF) in which the solvent is miscible and the solute is insoluble. Oversaturation and precipitation 24

25 Mass transfer phenomena diffusion of the antisolvent into the organic phase Particles formation and growth evaporation of the organic solvent into the antisolvent L+S M L SF N i = k L,SF a (C i e - C) M SF 25

26 Crystal surface Diffusion theory in crystal growth C ss Crystallization N = k c a drop (C ss - C s ) C s Dissolution N = k d a cry (C s - C bulk ) C bulk 26

27 Mass transfer & particle formation Contact area Miscibility of the solvent and SF Droplet size Weber number Mixing efficiency Reynolds number We= v a 2 r a d s N Re = rn sl h Ratio between disruptive fluid dynamic forces and shape maintaining interfacial forces N Re > turbulent flow N Re < laminar flow 27

28 SAS experimental set-up

29 Intensity (cps) SAS re-crystallization of didanosine from DMSO Commercial SAS at 200 bar PXRD Theta 2 (deg) 13 C CPMAS NMR 29

30 SAS re-crystallization of didanosine from DMSO particle size reduction and morphology D v (0.1) μm D v (0.5) μm D v (0.9) μm Commercial SAS at 100 bar SAS at 150 bar SAS at 200 bar

31 Particle size reduction vs CO 2 density

32 SAS re-crystallization of didanosine from DMSO Equilibrium solubility and dissolution rate Equilibrium solubility mg/ml Commercial 25.4 (0.7) 200 bar 26.9 (0.5)

33 Intensity (cps) Intensity (cps) SAS re-crystallization of didanosine from DMSO: mechanical stability Crystallinity and milling time Commercial product SAS recrystallized at 200 bar Commercial 2 hours milling 4 hours milling SAS from DMSO 30' milling 2 hours milling 4 hours milling Theta (deg) 2 Theta (deg) 33

34 PGSS Apparatus 1. CO 2 reservoir 2. Chiller 3. Pump 4. Inlet valve 5. Thermostat 6. Outlet valve 7. Thermostat 8. Micrometric valve 9. Nozzle 10. Precipitation and collection chamber

35 Precipitation and collecting chamber

36 CO 2 as plasticizing agent for PEG

37 Process yield and particle titles PEG 4000 dispersion Yield % Theor. % Actual % 5%, 55 C, 100 bar ± %, 55 C, 200 bar ± %, 55 C, 100 bar ± %, 55 C, 200 bar ± 0.19

38 Particle Size Distribution D v 0.1 ( m) D v 0.5 ( m) D v 0.9 ( m) Diazepam raw Microparticles with PEG C/100 bar C/150 bar C/200 bar C/250 bar Microparticles with PEG C/100 bar C/150 bar C/200 bar C/250 bar

39 Diazepam dissolution from PGSS produced PEG 4000 monostearate microparticles

40 Lorazepam as model compound BCS Class II Thermolabile molecule

41 Lorazepam dissolution from PGSS produced PEG 6000 microparticles Basket 100 rpm, 500 ml ph 6.5 buffer, 10 mg LZ, µm particle size 5% API 10%API

42 Intensità (cps) Lorazepam PEG 6000 solid dispersion physical stability PM PGSS 4 moths PGSS time zero Theta

43 Diazepam PEG 4000 microparticles from PGSS 55 C, 100 bar, 500X 55 C, 100 bar, 3300X 55 C, 200 bar, 430X 55 C, 200 bar, 850X

44 SEM images PGSS PEG 4000 particles

45 PEG 4000 particle density vs pressure

46 CO 2 as swelling agent for PEG 1500

47 Conclusions Supercritical fluids based processes are suitable for altering morphology, solid-state and particle size of pharmaceuticals Particles of a desired solid state can be produced by exploiting a broad set of operating conditions (T, p, solvent) Not a panacea. Useful for solving peculiar and specific problems Great expectation from multicomponent systems 47

48 Acknowledgement University of Parma Emilia Romagna Region MIUR, PRIN Program MAE, Italy-RSA Bilateral Agreement MAE, Vigoni Italy- Germany Bilateral Agreement

LIPE- Institut National des Sciences Appliquées 31077 Toulouse, France Contact: adamou@enstimac.fr

LIPE- Institut National des Sciences Appliquées 31077 Toulouse, France Contact: adamou@enstimac.fr Characterization of the ionic liquid bmimpf 6 in supercritical conditions Abla ADAMOU a, Jean-Jacques LETOURNEAU a, Elisabeth RODIER a, René DAVID a, Pascal GUIRAUD b a LGPSD- UMR CNRS 2392, Ecole des