1. Choi, P., W.J. Criddle andJ. Thomas (1979)Analyst 104, 451–455.
2. Houwen, O.A.G.J.Van Der (1980) Unpublished results.
3. Sane, R.T., P.D. Karkanis andP.G. Anaokar (1980)Ind. J. Pharm. Sci. 41, 143–144.
4. Sapio, J.P., K. Sethachutkul andJ.E. Moody (1979)J. Pharm. Sci. 68, 506–508.
5. Vaart, F.J. Van De, A. Hulshoff andA.W.M. Indemans (1980a)Pharm. Weekbl. 115, 1429–1438;Ibidem (1980b)Pharm. Weekbl. Sci. Ed. 2, 179–185;Ibidem (1982)Pharm. Weekbl: Sci. Ed. 4, 16–20.