Avicel ph101

Riboflavin, nicotinic acid, and ascorbic acid were provided by DSM Nutritional Products AG (DSM Nutritional Products AG, Kaiseraugst, Switzerland). Microcrystalline cellulose (Avicel^®PH101 and Avicel^®PH102, DuPont, Paris, France), a mixture of calcium hydrogen phosphate dihydrate, sodium starch glycolate and silicon dioxide (94:5:1) (Fagron, Capelle aan den IJsel, The Netherlands), magnesium stearate (Spruyt Hillen, Capelle aan den IJsel, The Netherlands), silicon dioxide (Spruyt Hillen, Capelle aan den IJsel, The Netherlands), methacrylic acid-methyl methacrylate copolymer 1:2 (Eudragit^® S100, Evonik industries AG, Essen, Germany), croscarmellose sodium (Ac-di-Sol^®, DuPont, Paris, France), talc (Duchefa Farma, Haarlem, The Netherlands), Polyethylene glycol 6000 (VWR, Amsterdam The Netherlands), acetone (Duchefa Farma, Haarlem, The Netherlands), red gelatin capsules size 0 (Spruyt Hillen, Capelle aan den IJsel, The Netherlands), and purified water were used for the production of the capsules. Riboflavin, nicotinic acid, and ascorbic acid were all of food grade, the other ingredients were pharmacopoeia grade (Ph. Eur. or USP/NF).

A powder mixture of hydralazine as the active pharmaceutical ingredient (API) and excipients was kindly provided by the Department of Pharmaceutical Technology (Faculty of Pharmacy in Hradec Králové, Charles University, Prague, Czech Republic). The powder mixture consisted of 15% hydralazine (Teva, Opava, Czech Republic), 25% microcrystalline cellulose Avicel^® PH101 (DuPont, Cork Ireland) and 60% anhydrous lactose NF DT^® (Foremost, Rothschild, Los Angeles, CA, USA). All the measurements and manipulations with the powder, granules and tablets were carried out at a controlled ambient temperature of 25.0 ± 2.0 °C and a relative air humidity of 40.0 ± 8.0%, analyzed using an E5005 hygrometer (Emos, Prerov, Czech Republic).

Fenofibrate was purchased from Acros Organics (Morris Plains, NJ, USA). The mesoporous silica (Parteck^® SLC, disordered pore size at 6 nm) was purchased from Millipore Sigma (St. Louis, MO, USA). The polymers polyvinylpyrrolidone K-90 (PVP K90) and hypromellose E15 (HPMC E15) were purchased from BASF (Florham Park, NJ, USA) and Ashland (Cherry Hill, NJ, USA), respectively. Avicel PH101 (lot# P118832588) was purchased from DuPont (Wilmington, DE, USA). Milli-Q water was obtained from Bristol Myers Squibb (Summit, NJ, USA). All organic solvents (HPLC grade), such as methanol and acetone, were purchased from Sigma-Aldrich (St. Louis, MO, USA). Simulated intestinal fluid (SIF) powder was purchased from Biorelevant.com Ltd. (London, UK).