MULTIPARTICULATES [CH. 12 137 Fig. 5—Influence of thermal treatment on the drug release from tablets containing 15% LMW DL-PLA, 25% theophylline and 60% microcrystalline cellulose. dissolution rate of tablets after thermal treatment. However, our preliminary results also suggest that the ratio of drug to excipient and the properties of the excipient may also exert a significant influence on the retardation mechanism of thermally treated compacts. REFERENCES 1 [] R.K.Kulkarni, E.G.Moore, A.F.Hegyeli and F.Leonard, J. Blomed. Mater. Res., 5, 169 (1971). 2 [] M.Anderson and F.Gibbons, Biomater., Med. Dev., Ary, Org., 2(3), 235 (1974). 3 [] S.Yolles and M.F.Sartori, in A.Kydonieus (ed.), <strong>Controlled</strong> <strong>Release</strong> <strong>Technology</strong>: Erodible Matrices, CRC Press, Boca Raton, 1980, p. 1. 4 [] B.Farhadieh, S.Borodkin and J.D.Buddenhagen, J. Pharm. Sci., 60, 209 (1971). 5 [] C.G.Pitt, M.M.Gratzl, A.R.Jeffcoat and R.Zweidinger, J. Pharm. Sci., 68, 1534 (1979). 6 [] J.Heller and R.W.Baker, Theory and Practice of <strong>Controlled</strong> <strong>Drug</strong> Delivery from Biodegradable Polymers, Academic Press, New York, 1980. 7 [] A.Schindler, J.F.Kimble and G.Pitt, Contemporary Topics in Polymer Science, Vol. 2, Plenum, New York, 1977, p. 271. 8 [] R.Bodmier and J.W.McGinity, Pharm. Res., 4, 465 (1987). 9 [] R.Chang, J.Price and C.Whitworth, <strong>Drug</strong> Dev. Ind. Pharm. 12(14), 2355 (1986). 10 [] Handbook of <strong>Pharmaceutical</strong> Excipients, Vol. 1, American Pharmacetical Association, Washington, DC, 1986, p. 53.
138 CH. 12] BIODEGRADABLE POLYMERS Fig. 6—Influence of thermal treatment on the drug release from tablets containing 15% LMW DL-PLA, 60% theophylline and 25% microcrystalline cellulose. Fig. 7—Influence of thermal treatment on the drug release from tablets containing 15% LMW L-PLA, 25% theophylline and 60% microcrystalline cellulose.