Vivapur 101

Felodipine (Nivedita Chemicals PVT Ltd, India); lactose monohydrate (LM) (Pharmatose 80M and Pharmatose 200M, DMV International, Holland) and microcrystalline cellulose (MC) (Vivapur 101 and Vivapur 102, JRS Pharma, Germany) were used as diluents; polyvinylpirrolidone – PVP (Kollidon K30, BASF, Germany) was used as binder; aqueous dispersion of ethyl acrylate and methyl methacrylate (Eudragit NE 40D, Evonix, Germany), acrylate, methyl methacrylate and a low content of methacrylic acid ester with quaternary ammonium groups (Eudragit RS 30D, Evonix, Germany), aqueous ethyl-cellulose dispersion (Surelease E719040, Colorcon, UK) were used as film forming polymers and low viscosity hydroxipropylmethylcellulose; HPMC (Methocel E5LV, Colorcon, U.S.A.) was used as a pore forming agent in the polymeric coating; triethyl citrate; TEC (Merck, Germany) was used as plasticizer in the polymeric coating. All the other substances used in this research were analytic grade from Merck, Germany.

The pharmaceutical excipient microcrystalline cellulose (MCC, x₁₀ = 20 μm, x₅₀ = 63 μm, x₉₀ = 139 μm, Vivapur® 101, JRS Pharma, Rosenberg, Germany) and the active pharmaceutical ingredient ibuprofen (IBU, x₁₀ = 9 μm, x₅₀ = 31 μm, x₉₀ = 34 μm Novartis Pharma, Basel, Switzerland) were selected as materials. MCC mainly consists of elongated primary particles and of approximately spherical agglomerates, while the particle shape of IBU is approximately rectangular (Fig. 1). The solid density determined by helium pycnometry is 1.544 g/cm³ for MCC and 1.112 g/cm³ for IBU. Additionally, magnesium stearate (Faci, Carasco GE, Italy) was used as lubricant.Fig. 1

SEM images of the MCC and IBU powders.

Fig. 1