Investigation of the solid state properties of amoxicillin trihydrate and the effect of powder pH

Abstract

The purpose of this research was to investigate some physicochemical and solid-state properties of amoxicillin trihydrate (AMT) with different powder pH within the pharmacopoeiaspecified range. AMT batches prepared using Dane salt method with the pH values from 4.39 to 4.97 were subjected to further characterization studies. Optical and scanning electron microscopy showed that different batches of AMT powders were similar in crystal habit, but the length of the crystals increased as the pH increased. Further solid-state investigations using powder x-ray diffraction (PXRD) demonstrated the same PXRD pattern, but the intensity of the peaks raised by the powder pH, indicated increased crystallinity. Differential scanning calorimetry (DSC) studies further confirmed that as the powder pH increased, the crystallinity and, hence, thermal stability of AMT powders increased. Searching for the possible cause of the variations in the solid state properties, HPLC analysis showed that despite possessing the requirements of the United States Pharmacopoeia (USP) for purity/impurity profile, there was a direct relationship between the increase of the powder pH and the purity of AMT, and also decrease in the impurity I (α-Hydroxyphenylglycine) concentration in AMT powder. Recrystallization studies confirmed that the powder pH could be controlled by adjusting the pH of the crystallization.

Overcoming the Cutaneous Barrier with Microemulsions

“…The ability of the final system to improve the transport of therapeutic agents into and across the skin is largely influenced by the internal structure and type of microemulsion used, as well as the composition and concentration of its components [27,46,47,48]. In fact, several studies demonstrate that the type of surfactant blend and/or co-surfactant used (as well as the ratio between them), the type of oil employed and the presence of penetration enhancers in microemulsions largely affect the skin penetration profile of a compound [27,46,47,48].…”

“…In fact, several studies demonstrate that the type of surfactant blend and/or co-surfactant used (as well as the ratio between them), the type of oil employed and the presence of penetration enhancers in microemulsions largely affect the skin penetration profile of a compound [27,46,47,48]. Depending on the physicochemical properties of the active substance, different types of microemulsions can be the optimal carrier.…”

Formulation of Dacarbazine-loaded Cubosomes. Part III. Physicochemical Characterization

“…These include indinavir-loaded microparticle (1,2) controlled-release baclofen tablets (3) bacterial cellulose (4), and solid state amoxicillin trihydrate (5). These drug formulation characterization approaches have been recently used for nanosuspension formulation as well (6).…”

Development of a magnetic system for the treatment of Helicobacter pylori infections

“…It is an efficient means of accessing the crystallization of amorphous polymers used in drug formulations [24]. In Fig.…”

“…3, may come both from the original amoxicillin structure [28], or the crystallization of the Eudragit s S100 polymer in the spray drier process (Fig. 3).…”