ABSTRACT
Sustained release dosage forms are a convenient means to obtain a reduction in daily administration of drugs with fast absorption and/or elimination. In this study three different drugs are compared: one is slightly water soluble, and two are highly water soluble (Table 1). Production of hydrophilic matrices is a well-known technology, by direct compression as well as by wet granulation [1,2]. A lot of research has been done and the literature on this subject is plentiful. Different polymers may be used to control the diffusion of the drug. Among them, hydroxypropylmethylcellulose (HPMC) seems most employed [3-5]. Table 1-Drug characteristics
MATERIALS
The following ingredients were used for the preparation of hydrophilic matrices: calcium hydrogen phosphate dihydrate, (SPCI, La Plaine Saint Denis), calcium hydrogen phosphate for direct compression (Emcompress, SPCI), lactose 150 mesh (Sucre de Lait, Sains-du-Nord),
lactose Fast Flo (SEPPIC, Paris), polyvinylpyrrolidone (PVP) (Luviscol K30, BASF, Levallois), HPMC (Methocel K4M and E4M CR, Colorcon, Bougival or Metolose 60SH4000 and 90SH4000, SEPPIC), hydroxyethylcellulose (HEC) (Natrosol, Aqualon, Rueil-Malmaison), magnesium stearate (Stéarinerie Dubois, Paris) and colloidal silicon dioxide (Aerosil 200, Degussa, Neuilly sur Seine).
