Stability evaluation of compounded clonidine hydrochloride oral liquids based on a solid-phase extraction HPLC-UV method

The present study aimed to assess the stability of clonidine hydrochloride oral liquids (20-μg/mL) prepared from two different generic tablets in Ora-Blend and stored in amber plastic bottles. Physical and chemical stabilities were evaluated over a period of 90 days at 25°C. Analytical challenges were overcome with the development of a new extraction procedure based on solid phase extraction to ensure efficient clonidine hydrochloride quantification. The absence of physical instabilities, evaluated by qualitative and quantitative measurements (static multiple light scattering), as well as the absence of chemical instabilities, evidenced by a stability-indicating HPLC-UV method, confirmed that a beyond-use date of 90 days was appropriate for these compounded oral liquids.

Peter Gray. 25 August 1926 — 7 June 2012

Peter Gray was an internationally recognized research leader in the areas of combustion chemistry and chemical instabilities. His undergraduate education and early research career were in Cambridge. He moved to the University of Leeds in 1955, becoming Head of Physical Chemistry there in 1965. In 1988 he returned to Cambridge as Master of Gonville and Caius College. Peter’s scientific contributions covered experimental and theoretical studies of chemical and thermal instabilities in combustion systems and in isothermal systems exhibiting autocatalysis, and of flames and chemical waves. His work provided the framework for understanding the thermokinetic origin of cool flames and multiple-stage ignitions and for the onset of ignition and oscillations in chemical systems more generally. He served on a series of important government committees and held major office for the Faraday Society and the Combustion Institute. He published more than 300 research articles and one monograph and was awarded a series of major prizes, including the Marlow Medal, the Bernard Lewis Gold Medal and the Italgas Prize.

EFFECTS OF THE ω MESON SELF COUPLING ON THE THERMAL PROPERTIES OF ASYMMETRIC NUCLEAR MATTER

Effects of the ω meson self coupling (OMSC) on the thermal properties of asymmetric nuclear matter (ANM) are studied within the framework of relativistic mean field (RMF) model that includes contributions of all possible mixed interactions among meson fields involved up to quartic order. In particular, we study the mechanical and chemical instabilities (spinodal), as well as the liquid-gas phase transition (binodal) at finite temperature. It is found that the onset of spinodal instabilities and the binodal curve are only marginally affected by variation of the OMSC parameter, whereas the binodal curve shows a strong correlation to the symmetry energy. Comparison with other ERMF parameter sets is also performed.