Quantitative determination of solid-state forms of a pharmaceutical development compound in drug substance and tablets.

Common analytical techniques including Raman, NIR, and XRD were evaluated for quantitative determination of three solid-state forms (amorphous, Form B and Form C) of a development compound. Raman spectroscopy was selected as the primary analytical technique with sufficient sensitivity to monitor and quantify the neat drug substance alone and in the drug product. A reliable multivariate curve resolution (MCR) method based on the second derivative Raman measurements of the three pure physical forms was developed and validated with 3.5% root mean square error of prediction (RMSEP) for Form B, which was selected as the preferred form for further development. A partial least squares (PLS) algorithm was also used for the multivariate calibration of both the NIR and Raman measurements. The long-term stability of Form B as a neat active pharmaceutical ingredient (API) and in a tablet formulation was quantitatively monitored under various stress conditions of temperature and moisture. Moisture, temperature, excipients and compression were found to have significant effects on the phase transition behavior of Form B.

The benefits of renin-angiotensin blockade in renal transplant recipients with biopsy-proven allograft nephropathy.

BACKGROUND: Allograft nephropathy, regardless of aetiology, leads to progressive renal injury and eventual graft loss. In native kidney disease, treatment of hypertension, in particular with angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB), has proven beneficial in retarding renal function decline. In the present study, we reviewed the clinical course of a renal transplant recipient cohort that was prescribed either an ACEi or ARB for biopsy-proven allograft nephropathy. METHODS: Patients were followed from the time of post-biopsy initiation of ACEi/ARB and were stratified based on biopsy findings. Outcomes of interest included safety, allograft survival, renal function and change in slope of renal function pre- and post-ACEi/ARB. RESULTS: The 5 year allograft survival after biopsy diagnosis of allograft nephropathy was 83%. Serum creatinine was 191+/-97 (86-377) micromol/l at the time of biopsy and 228+/-102 (102-575) micromol/l at last follow-up. The slopes of reciprocal creatinine vs time were used to calculate the decline in renal function and were compared pre- and post-ACEi/ARB. The mean slope+/-SD was -0.06+/-0.21 l/micromol x 10(-3) per month in the 12 months prior to therapy and -0.03+/-0.09 l/micromol x 10(-3) per month following therapy. The absolute difference in slopes was 0.03 (P =<0.0001). CONCLUSIONS: Treatment with ACEi/ARB may be beneficial in the management of allograft nephropathy.