1. Langer, R. New methods of drug delivery. Science 249, 1527–1532 (1990).
2. Putney, S.D. & Burke, P.A. Improving protein therapeutics with sustained-release formulations. Nat. Biotechnol. 16, 153–157 (1998).
3. Banerjee, P.S., Hosny, E.A. & Robinson, J.R. Parenteral delivery of peptide and protein drugs. in Peptide and Protein Delivery, Vol. 4 (ed. Lee, V.H.L.) 487–543 (Marcel Dekker, Los Angeles, 1991).
4. Shah, V.P., Skelly, J.P., Barr, W.H., Malinowski, H. & Amidon, G. Scale-up of controlled release products—preliminary considerations. Pharm. Technol. 5, 35–40 (1992).
5. Hagedorn, H.C., Jensen, B.N., Krarup, N.B. & Wodstrup, I. Protamine insulinate. JAMA 106, 177–180 (1936).