Biopharmaceutics

Biography

Biography: Monica C Chuong

Abstract

Niacin and lovastatin are cholesterol lowering drugs. Niacin synthesized from tryptophan belongs to BCS class 1 with pKa 2.17 and plasma t1/2 20-48 min. Lovastatin naturally occurring in oyster mushrooms was isolated from Aspergillus terreus in 1982 and derived from red yeast rice in 1998. It is classified as BCS class 2 with pKa 13.49 andt1/2 4.5h. This presentation aims (1) to review lovastatin production using submerged culture vs. solid state fermentation of Aspergillus terreus and various chemically defined media, (2) toelucidate the fabrication ofa two-layer tablet design containing 250 mg niacin and 20 mg lovastatin, (3) to describe the formulation of a 20 mg lovastatin mini tablet in the delayed-then-extended dissolution release manner (without niacin). For aim 1, five literatures will be summarized. For aim 2, niacin heated with carnauba wax and stearic acid to blend. Once cooled, the solid mixture was tritulated with Carbomer 940 NF, Methocel K4M CR, sodium starch glucolate and Kollidone VA 64 to compress into a caplet. Ground mixture of lovastatin (the second drug), magnesium stearate, SDS and Avicel PH100 were added on top of niacin caplet to compress into the second layer. For aim 3, beta-cyclodextrin was complexed with lovastin (1:1 molar ratio) in hydroalcoholic solution. Once evaporated dried, this powder added with other excipients was compressed into mini tablets containing 20 mg lovastatin each. These cores were further enteric coated with a dispersion of Eudragit L 30D-55 and water (1:1 v/v). Content assay and in vitro release samples were quantified by HPLC.DSC confirmed no interaction between lovastatin and excipients. This project recommends that niacin (a rather acidic very water soluble small molecule) and lovastatin (an acid labile poorly water soluble macromolecule) be formulated separately.