Effect of Excipients on Dissolution: Case Studies with Bio-relevant/ Hydro-alcoholic Media

Effect of Excipients on Dissolution: Case Studies with Bio-relevant/ Hydro-alcoholic Media Sandip B. Tiwari, Ph.D. Technical Director: South Asia Colorcon Asia Pvt. Ltd., Goa, India DISSO-INDIA 2013, May 03-04, 2013

Outline Dissolution test: basics Tests before bio-study What controls the release profiles Formulation excipients or test conditions Variability levels of the formulation: effects of excipients/ technology Fed and fasted effects Effect of hydro-alcoholic media: effect of formulation excipients

Oral Drug Delivery Heart Liver (Metabolism?) Site of Action? Mucosal lining Drug Absorption Drug Mouth Stomach Drug Release from Dosage Forms Drug Dissolution Membrane Transport Small Intestine Large Intestine Rectum Reasons for poor bioavailability: No dissolution at absorption site Degradation / non absorbable complex / metabolism / Low permeability

Dissolution Test A measure of the proportion of drug dissolving in a stated time under standardized conditions in-vitro. The Pharmacopoeia stresses that in the majority of cases no attempt has been made to correlate dissolution results with invivo data. In a few cases, the in-vitro dissolution data correlates with in-vivo performance. Quality control: - Process control - Batch-to-batch quality

Factors Affecting Dissolution of an API Intrinsic dissolution rate (substance related) Chemistry, polymorphic nature, crystalline or not, etc Volume of liquid to dissolve in! Differences between GIT and USP Composition of the media Difficult to replicate the GIT due to its variability Agitation rate Differences between USP methods and GIT Time allowed to be dissolved / removed (absorbed) Sink condition (differences between USP and GIT) Immediate environment (formulation type/ excipients) Other factors: temperature, viscosity, surface area etc

USP Dissolution Apparatus USP apparatus Suitable for Agitation method Standards 1 Basket Solids, beads, capsules, floaters, MR 2 Paddle Solids, suspension, MR, Patches 3 BioDis Non-disintegrating tablets and Beads, MR 4 Flow-through cell Solids, powders, beads, implants Rotating stirrer Rotating stirrer Dipping rate Fluid movement 5 Paddle over disc Patches Rotating stirrer 900 ml 32 C 6 Cylinder Patches Rotating stirrer 900 ml 32 C 40 mesh basket 100 rpm 900 ml at 37 C Inert material 900 ml at 37 C 50 rpm Sinkers Mesh screen at top and bottom 200-250 ml Variations in Size, flow rate, filters 7 Reciprocating holder Patches, solids Reciprocation Sample holder 50-200 ml 32 C

Does the Dissolution Tester Simulate This? Antral contraction waves

Diltiazem HCl ER Tablet Release in Buffer Media at 37 0 C Drug released (%) 100 90 80 70 60 50 40 30 20 10 0 Paddle 50rpm Basket 50 rpm Paddle 100rpm Basket 100rpm Paddle 75rpm Basket 75rpm 0 2 4 6 8 10 12 14 16 Time (hours)

Biorelevant Dissolution Media Fasted state Stomach: FaSSGF: simulates reduced surface tension in the stomach Small intestine: FaSSIF to simulate basal bile secretion Colon: SCOF (ph 5.8 acetate buffer) Fed State Stomach: Ensure Plus to simulate gastric conditions after a standard breakfast Small intestine: FeSSIF to simulate postprandial bile secretion, increased buffer capacity and osmolality after food intake Based on J. Dressman s recommendation

In Vitro Simulation of the Gastric Contents: Preprandial (FaSSGF) HCl (ph 1.2-2.0) Pepsin 0.01-0.05 N 1.0 mg/ml Na Taurocholate 80 µm Sodium chloride Distilled Water 2.0 g qs 1000 ml Based on Vertzoni et al. J.Pharm Pharmacol. (2005)

Simulation of Fasted State in the Small Intestine: FaSSIF NaH 2 PO 4 1.977 g Sodium taurocholate 3 mm Lecithin 0.75 mm NaCl 3.093 g NaOH qs ph 6.5 Distilled Water qs 500 ml ph 6.5 Osmolality 270 + 10 mosm Buffer Capacity 10 + 2 meq/l/ph unit

Simulation of Fed State in the Small Intestine: FeSSIF Acetic acid 8.65 g Sodium taurocholate 15 mm Lecithin 3.75 mm Glycerolmonooleate 5 mm NaCl 11.874 g NaOH qs ph 5 Distilled Water qs 1 Liter ph 5 Osmolality 635 + 10 mosm Buffer Capacity 76 + 2 meq/l/ph unit

Simulating GIT: USP Apparatus 3 (BioDis ) Useful for non disintegrating tablets / beads MR dosage forms

USP Apparatus 3 - BioDis 6 rows of vessels variable ph values and media different residence times per medium variable passage times variable volumes: 200 250 ml per vessel dip rate 5 40 dpm: variable motility patterns mesh sizes 75-840 µm: variable hydrodynamics complex media: food effects

Case Studies: Testing Setup Tests 8 tablet at a time Six sequential media for each tablet Automatic sampler for each media at programable times Sample Analysis using HPLC Adjustable dip rates and screen sizes for variable hydrodynamics 20, 30, 40 Mesh 5 to 40 dpm

Case Studies: Bio-relevant Media and Physiological Residence Times ** Halved bile salts

Verapamil 240mg ER Formulation Based on HyperStart Material %w/w mg/tablet Verapamil HCl 47.8 240.0 HPMC (Methocel K100LV CR) 30.0 150.0 HPMC (Methocel E5)* 0.4 2.0 Lactose-spray dried (Fast Flo NF) 20.9 105.0 Colloidal silicon dioxide (CAB-O-SIL M- 5) 0.5 2.5 Magnesium stearate NF 0.5 2.5 Total: 100.0 502.0 *Methocel E5 was used as a wet granulation binder

Verapamil 240mg ER (n=6) USP II- 50 & 100rpm Dissolution medium 900ml of simulated gastric and intestinal fluid no enzymes (37 ± 0.5 C) Percent Dissolved 100 90 80 70 60 50 40 30 20 10 0 0 60 120 180 240 300 360 420 480 Time (Minutes) Verapamil HCl 240 mg SR USP Low USP High

Verapamil 240mg ER (n=6) USP II- 100rpm Dissolution medium 900ml of simulated gastric and intestinal fluid no enzymes (37 ± 0.5 C) 100 90 80 70 Drug Released (%) 60 50 40 30 20 10 0 0 1 2 3 4 5 6 7 8 Time (Hours) Verapamil HCl 240mg ER USP Low USP High Isoptin Marketed SR Brand

Verapamil 240mg ER: Apparatus 3 Fasting state Fed state 120 120 Verapamil released [%] 100 80 60 40 20 Colorcon ADS-I Calan SR 240 mg Verapamil released [%] 100 80 60 40 20 Colorcon ADS-I Calan SR 240 mg 0 0 200 400 600 800 1000 1200 Time [min] 0 0 200 400 600 800 1000 1200 Time [min]

Verapamil 240mg ER: Apparatus 3 Colorcon Formulation Innovator Formulation 120 120 Verapamil released [%] 100 80 60 40 20 0 Colorcon ADS -1 Fasted Colorcon ADS -1 Fed 0 200 400 600 800 1000 1200 Verapamil released [%] 100 80 60 40 20 0 Calan SR 240 mg Fasted Calan SR 240 mg Fed 0 200 400 600 800 1000 1200 Time [min] Time [min]

Carbamazepine 200mg ER Formulation Based on HyperStart Material Supplier %w/w mg/tablet Carbamazepine Max Pharma, DE 57.14 200.00 HPMC (Methocel K100LV CR) Colorcon Ltd, UK 30.00 105.00 MCC 90µm (Avicel PH102) FMC, Ireland 10.95 38.32 HPMC (Methocel E3LV)* Colorcon Ltd, UK 0.16 0.56 Sodium lauryl sulphate** Stepan, UK 0.50 1.75 Fumed silica (Aerosil 200) Degussa, France 1.00 3.50 Magnesium stearate Peter Greven, UK 0.25 0.87 Total: 100.00 350.00 * Methocel E3LV was used as a WG binder. ** Sodium lauryl sulphate (SLS), a surfactant was used within the binder solution to improve carbamazepine solubility.

Carbamazepine 200mg ER (n=6) USP I 100 rpm Dissolution medium - 900ml of purified water, 37.0 ± 0.5ºC 100 90 80 Drug Released (%) 70 60 50 40 30 20 10 Carbamazepine (200mg) ER Matrix USP Lower Acceptance Criteria USP Upper Acceptance Criteria 0 0 2 4 6 8 10 12 14 16 18 20 22 24 Time (hours)

Carbamazepine 200mg ER: USP3 Fasting state Fed state 80 80 70 70 CBZ released [%] 60 50 40 30 20 10 Colorcon ADS Tegretol XR 200 mg CBZ released [%] 60 50 40 30 20 10 Colorcon ADS Tegretol XR 200 mg 0 0 200 400 600 800 1000 1200 0 0 200 400 600 800 1000 1200 Time [min] Time [min]

Carbamazepine 200mg ER: USP3 Colorcon Formulation Innovator Formulation 80 80.0 70 70.0 CBZ released [%] 60 50 40 30 20 10 Colorcon ADS - Fasted Colorcon ADS - Fed CBZ released [%] 60.0 50.0 40.0 30.0 20.0 10.0 Tegretol XR 200 mg - Fasted Tegretol XR 200 mg - Fed 0 0 200 400 600 800 1000 1200 0.0 0 200 400 600 800 1000 1200 Time [min] Time [min]

Metformin 500mg ER Formulation Based on HyperStart Material Supplier %w/w mg/tablet Metformin HCl Ferico Labs 50 500 Methocel K100M CR Colorcon 30 300 Avicel PH102 FMC 19 190 Aerosil 200 Degussa 0.5 5 Magnesium stearate Peter Greven 0.5 5 Total: 100% 1000mg

Metformin 500mg ER (n=6) USP II -100 rpm Dissolution medium - 1000ml of purified water, 37.0 ± 0.5 C % drug release 110 100 90 80 70 60 50 40 30 20 10 0 Glucophage XR 500mg tablets Colorcon 500mg Metformin MR tablets 0 100 200 300 400 500 600 700 800 Time (mins)

Metformin 500mg ER: Apparatus 3 Fasting state Fed state 120 120 Metformin released [%] 100 80 60 40 20 Colorcon ADS Glucophage XR 500 mg Metformin released [%] 100 80 60 40 20 Colorcon ADS Glucophage XR 500 mg 0 0 200 400 600 800 1000 1200 0 0 200 400 600 800 1000 1200 Time [min] Time [min]

Metformin 500mg ER: Apparatus 3 Colorcon Formulation Innovator Formulation 120 120 Metformin released [%] 100 80 60 40 20 Colorcon ADS Fasted Colorcon ADS Fed Metformin released [%] 100 80 60 40 20 Glucophage XR 500 mg Fasted Glucophage XR 500 mg Fed 0 0 200 400 600 800 1000 1200 0 0 200 400 600 800 1000 1200 Time [min] Time [min]

Some Biopharmaceutic Considerations Transit / window of absorption Elimination path / first pass metabolism issue Fed versus fasted API absorption / complexation Dosage form effects Osmotics Matrices Barrier membrane MPs Reduced toxicity related to C max

Potential Effects of Alcohol on ER Dosage Forms In July 2005 the FDA issued an alert for healthcare professionals regarding an alcohol-palladone TM interaction. Palladone TM is a once-daily opioid capsule containing pellets each of which has drug embedded in an ER matrix Strengths: 12 mg, 16 mg, 24 mg, 32 mg hydromorphone HCl No food effect or ph effect When ingested with alcohol the peak plasma concentration of hydromorphone increased to potentially lethal levels due to breakdown of the ER formulation. The objective of this study was to investigate the influence of hydroalcoholic solutions on the hydration, swelling and gel formation of HPMC compacts and drug release from their matrices.

Solubility of the Tested Drugs (Martindale, 1999) Active Felodipine Gliclazide Metformin HCl Solubility in water Practically insoluble Practically insoluble Freely soluble Solubility in alcohol freely soluble in absolute alcohol, in methyl alcohol slightly soluble in alcohol slightly soluble in alcohol

Felodipine 5 mg HPMC ER Formulation Material Supplier % w/w mg/tablet Felodipine Spodefell, UK 2.5 5 HPMC (Methocel K100LV CR) Lactose (Fast Flo ) Colorcon Ltd, UK 37.0 74 Foremost Farms, USA 59.5 119 Fumed silica (Aerosil 200) Degussa, France 0.5 1 Magnesium stearate Peter Greven, UK 0.5 1 Total 100.0 200

Gliclazide 30 mg HPMC ER Formulation Material Supplier % w/w mg/tablet Gliclazide HPMC (Methocel K100LV CR) Microcrystalline cellulose 90m Fumed silica (Aerosil 200) Synergy Enterprises, India 15.0 30 Colorcon Ltd, UK 35.0 70 FMC, Ireland 49.0 98 Degussa, France 0.5 1 Magnesium stearate Peter Greven, UK 0.5 1 Total 100.0 200

Metformin HCl 500 mg HPMC ER Formulation Material Supplier % w/w mg/tablet Metformin HCl Ferico Labs, India 50.0 500 HPMC (Methocel K100M CR) Colorcon Ltd, UK 30.0 300 Microcrystalline cellulose 90m FMC, Ireland 19.0 190 Fumed silica (Aerosil 200) Degussa, France 0.5 5 Magnesium stearate Peter Greven, UK 0.5 5 Total 100.0 1000

Dissolution Media Selection 5% v/v ethanol 40% v/v ethanol

For How Long to Test in Hydro-Alcoholic Media? Duodenum Stomach Jejunum Ileum Ascending colon

Felodipine Release Profiles 12 hours in hydro-alcoholic media 1 hour in hydro-alcoholic media 100 100 90 90 80 80 Drug released (%) 70 60 50 40 30 20 10 0 In ph 6.5 phosphate buffer + 1% SLS In 5% v/v ethanol solution in phosphate buffer + 1% SLS In 40% v/v ethanol solution in phosphate buffer + 1% SLS 0 1 2 3 4 5 6 7 8 9 10 11 12 Drug released (%) 70 60 50 40 30 20 10 0 No exposure to alcohol 1 hour in 5% v/v aqueous ethanol solution 1 hour in 40% v/v aqueous ethanol solution 0 1 2 3 4 5 6 7 8 9 10 11 12 Time (hours) Time (hours)

Gliclazide Release Profiles 12 hours in hydro-alcoholic media 1 hour in hydro-alcoholic media 100 90 100 90 Drug Released (%) 80 70 60 50 40 30 20 10 0 0 1 2 3 4 5 6 7 8 9 10 11 12 Time (hours) In purified water In 5% v/v aqueous ethanol solution In 40% v/v aqueous ethanol solution % drug release 80 70 60 50 40 30 20 10 0 0 1 2 3 4 5 6 7 8 9 10 11 12 Time (hours) In purified water 1 hour in 5% v/v aqueous ethanol solution 1 hour in 40% v/v aqueous ethanol solution

Metformin HCl Release Profiles 100 90 12 hours in hydro-alcoholic media 100 90 1 hour in hydro-alcoholic media Drug released (%) 80 70 60 50 40 In purified water Drug released (%) 80 70 60 50 40 In purified water 30 20 10 In 5% v/v aqueous ethanol solution In 40% v/v aqueous ethanol solution 30 20 10 1 hour in 5% v/v aqueous ethanol solution 1 hour in 40% v/v aqueous ethanol solution 0 0 1 2 3 4 5 6 7 8 9 10 11 12 0 0 1 2 3 4 5 6 7 8 9 10 11 12 Time (hours) Time (hours)

Saturated Solubility of the Candidate Drugs in Various Media (g/l) Felodipine Gliclazide Metformin HCl Water 0.002 0.045 450.413 5% v/v ethanol in water 0.005 0.054 378.647 40% v/v ethanol in water 2.490 0.503 295.466 ph 6.5 phosphate buffer + 1% SLS 5% v/v ethanol in phosphate buffer + 1% SLS 40% v/v ethanol in phosphate buffer + 1% SLS 0.811 - - 0.721 - - 4.374 - -

Values of f 2 for Drug Release Profiles from HPMC Matrices in Various Media Dissolution medium 5% v/v ethanol 40% v/v ethanol Duration of exposure to alcohol containing media Felodipine formulation Gliclazide formulation Metformin HCl formulation 12 hours 1 hour 12 hours 1 hour 71 76 63 63 80 65 79 55 68 86 44 54

Hydro-Alcoholic Media Uptake of Methocel Compacts (n = 3) 1000 900 Compact wet weight (mg) 800 700 600 500 400 300 200 100 0 0 10 20 30 40 50 60 70 80 90 100 110 120 Time (min) K100LV CR (0:100 ethanol: w ater) K100LV CR (25:75 ethanol: w ater) K100LV CR (50:50 ethanol: w ater) K4M CR (0:100 ethanol: w ater) K4M CR (25:75 ethanol: w ater) K4M CR (50:50 ethanol: w ater) K100M CR (0:100 ethanol: w ater) K100M CR (25:75 ethanol: w ater) K100M CR (50:50 ethanol: w ater)

Hydro-Alcoholic Media Uptake of Methocel Compacts (n = 3) In water and hydro-alcoholic solutions all compacts underwent swelling and gelation without any disruption to the matrix integrity. A similar progressive weight gain by compacts in water and hydro-alcoholic media with time occurred. The extent of swelling increased with increasing viscosity grade of HPMC from 100 to 4000 cps. No significant difference in compact relative swelling was observed for Methocel K4M CR and K100M CR.

Solubility of Tableting Fillers in Various Media (Handbook of Pharmaceutical Excipients, 2003) What about other factors, i.e. differences in the solubility of matrix ingredients in various media? The most commonly used fillers in HPMC matrices are microcrystalline cellulose (MCC), lactose, pregelatinized starch (PGS) and dibasic calcium phosphate dihydrate (DCPD). The effect of hydro-alcoholic media exposure on tablets with different fillers will probably increase in the following order: MCC or DCPD -> PGS - > lactose (In felodipine formulation no significant effect)

Solubility of Tableting Fillers in Various Media (Handbook of Pharmaceutical Excipients, 2003) Filler Solubility in water Solubility in alcohol MCC Practically insoluble Practically insoluble in most organic solvents Lactose 1 in 4.63 Practically insoluble in ethanol PGS Slightly soluble to soluble Practically insoluble in organic solvents DCPD Practically insoluble Practically insoluble in ethanol

Conclusions ER HPMC tablets of felodipine 5 mg, gliclazide 30 mg and metformin HCl 500 mg retained their hydrated structural integrity when exposed to 5% and 40% v/v ethanol solutions for up to 12 hours without any failure of the matrices resulting in dosedumping. Drug release profiles from these ER metformin HCl tablets were different when exposed to 0% and 40% v/v ethanol solutions for 12 hours that were explained by changes in drug solubility. When the matrices were exposed to hydro-alcoholic media for only 1 hour the change in drug release profiles was not significant.

Summary Formulation excipients or test conditions dictate the drug release profile. Use of Apparatus I or II may not show differences in in-vitro behavior of formulations vis-à-vis innovator formulations prior to bio-study conclusion. Use of Apparatus III with simulated bio-relevant media could be a good tool to indicate performance of formulations in-vitro, and possibly in-vivo Effect of hydro-alcoholic media on drug release profile is dictated by solubility of API/ excipients and duration of exposure.