Yes / Objectives In this work we investigated the residual organic solvent content and physicochemical properties of spray-dried chlorothiazide sodium (CTZNa) and potassium (CTZK) salts.
Methods The powders were characterised by thermal, X-ray diffraction, infrared and dynamic vapour sorption (DVS) analyses. Solvent levels were investigated by Karl–Fischer titration and gas chromatography.
Key findings Spray-drying from water, methanol (MeOH) and mixes of MeOH and butyl acetate (BA) resulted in amorphous microparticles. The glass transition temperatures of CTZNa and CTZK were ∼192 and ∼159°C, respectively. These materials retained their amorphous nature when stored at 25°C in dry conditions for at least 6 months with no chemical decomposition observed. DVS determined the critical relative humidity of recrystallisation of CTZNa and CTZK to be 57% RH and 58% RH, respectively. The inlet temperature dependant oxidation of MeOH to formaldehyde was observed; the formaldehyde was seen to deposit within the amorphous matrix of spray-dried product. Spray-drying in the open blowing mode coupled with secondary drying resulted in a three-fold reduction in residual BA (below pharmacopoeial permitted daily exposure limit) compared to spray-drying in the closed mode.
Conclusions Experiments showed that recirculation of recovered drying gas increases the risk of deposition of residual solvents in the spray-dried product. / The Irish Research Council for Science and Engineering Technology (IRCSET), the Solid State Pharmaceutical Cluster (SSPC), supported by Science Foundation Ireland under grant number (07/SRC/B1158) and the Irish Drug Delivery Research Network, a Strategic Research Cluster grant (07/SRC/B1154) under the National Development Plan co-funded by EU Structural Funds and Science Foundation Ireland.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/14361 |
| Date | 24 May 2012 |
| Creators | Paluch, Krzysztof J., Tajber, L., Amaro, M.I., Corrigan, O.I., Healy, A.M. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, Accepted manuscript |
| Rights | © 2012 Wiley This is the peer reviewed version of the following article: Paluch KJ, Tajber L, Amaro MI et al (2012) Impact of process variables on the micromeritic and physicochemical properties of spraydried microparticles – Part II. Physicochemical characterisation of spray-dried materials. 64(11): 1583-1591., which has been published in final form at http://dx.doi.org/10.1111/j.2042- 7158.2012.01543.x. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving., Unspecified |
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