Determination of organic impurities in pharmaceutical preparations

Abstract

Data reported in the literature on methods for the determination of organic impurities in pharmaceutical preparations are systematized; the characteristics and possibilities of the methods are compared.

Colloidal astaxanthin: Preparation, characterisation and bioavailability evaluation

“…Generally, the solvent evaporation from dispersion systems is a two-stage process, first, depends on the volatility and vapor pressure of the solvent that was limited by the boundary layer phenomenon, and the second, depends on internal diffusion ability (known as diffusion coefficient) that depends on the molecular branching and molecular size. Previous researches showed that the molecular nature of solvent which governs the molecular interactions (van der Waals/hydrogen bonds) between the solvent and other dispersion components has the highest effect on the solvent residual of the nanodispersion systems compared to the molecular characteristics and consequently the stabilizer nature of colloidal particles (Glazkov, Bochkareva, & Revel'skii, 2005;Witschi & Doelker, 1997).…”

Isolation of oxidative degradation products of atorvastatin with supercritical fluid chromatography

“…The concentration of structurally related compounds (related impurities) in small quantities in the active substance is limited to very low levels by the Pharmacopoeia specifications. They may cause adverse effects owing to their potential pharmacological and toxicological properties and are therefore potentially harmful (Glazkov et al, 2005). Furthermore, the study of the impurity profile and their structure elucidation is of great interest to chemists in developing the synthesis of the active substances.…”

“…When the impurity in the API is present in quite a low concentration, chromatography is applied. The most popular methods are thin-layer and especially preparative high-performance liquid chromatography (HPLC) (Glazkov et al, 2005). In this paper a technique with major potential in the field of isolation of impurities, that is, supercritical fluid chromatography (SFC), was applied.…”