An HPLC method for the separation of six target alkaloids from Papaver somniferum L. (morphine, codeine, oripavine, thebaine, papaverine, and noscapine) was developed, optimized, and validated. The chromatographic behavior of these alkaloids was investigated using a reversed-phase chromatography at acidic and alkaline pH. The effects of ion-pairing agents, pH value of the mobile phase, concentration of the buffer components, mobile phase organic modifier, and column temperature were studied. Regardless of the large differences in their pKa values, all alkaloids were separated within a close retention window, and good peak shape was achieved for each of the six alkaloids. The proposed method has adequate selectivity, linearity, accuracy, precision, and reproducibility and is applicable for poppy straw.

A new Hydrophilic Interaction Liquid Chromatography (HILIC) method was developed for simultaneous determination of cetylpyridinium chloride and benzocaine as active substances in lozenges. Method development included investigation of the influence of the critical chromatographic conditions such as: type of organic modifier, mobile phase strength, ionic strength and pH value of the buffer used in the mobile phase, as well as experimental determination of dominant mechanism of retention. The optimal chromatographic conditions were obtained using bare silica column and a mobile phase consisting of acetonitrile and ammonium formate (50 mM, pH = 4.0) in ratio 80 : 20 V/V. The method was validated in terms of specificity, linearity, accuracy and precision. The validation results indicate that the proposed HILIC method is suitable for quantitative analysis of cetylpyridinium chloride and benzocaine in lozenges.

The increasing environmental concerns and regulatory restrictions on toxic conventional solvents have driven the search for sustainable alternatives. Dimethyl isosorbide (DMI), a bio-renewable solvent, has shown potential as a replacement for short-chain glycol ethers, although its use as solvent in liquid chromatography (LC) is underexplored. This study presents a physicochemical characterization of DMI with a particular focus on its application as an innovative solvent in LC analyses. The partition coefficient (log P = −0.44) was determined using the OECD 107 method, and viscosity measurements for DMI and its mixtures with water and ethanol were conducted at 25 °C, 40 °C, and 60 °C. Viscosity ranged from 1.28 mPa·s at 60 °C to 2.62 mPa·s at 40 °C. The Central Composite Face 2³ experimental design for studying the chromatographic behavior of DMI confirmed that 50% (v/v) DMI can be effectively utilized in the mobile phases, at a column temperature of 40 °C, with backpressures ranging from 160 to 300 bar and a UV cut-off at 240 nm. Its effectiveness as an eluent in LC was demonstrated for the quantification of methylparaben and propylparaben in pharmaceutical formulations. This study highlights DMI’s promise as a sustainable bio-renewable alternative to conventional organic solvents used as eluents in LC, supporting eco-friendly practices in pharmaceutical analysis.

Objective: Antibodies to ganglioside GM1 are associated with Guillain-Barré Syndrome (GBS) in patients with serologic evidence of a preceding infection with Campylobacter jejuni. Molecular mimicry between C. jejuni Lipopolysaccharide (LPS) and ganglioside GM1 has been proven to be the immunopathogenic mechanism of the disease in the axonal variant of GBS. GM1-positive sera cross-react with several Gal-GalNAc-bearing glycoproteins from the human peripheral nerve and C. jejuni (O:19). This study aimed to examine the immunoreactivity of the digested cross-reactive glycoproteins isolated from the human peripheral nerve and C. jejuni (O:19) with Peanut Agglutinin (PNA) as a marker for the Gal-GalNAc determinant, and with sera from patients with GBS. Materials and Methods: For this purpose, the cross-reactive glycoproteins from peripheral nerve and C. jejuni (O:19) were enzymatically digested with trypsin and the obtained peptides were incubated with PNA and GBS sera. Results: Western blot analysis of the separated peptides revealed several bands showing positive reactivity to PNA and to sera from patients with GBS, present in both digests from peripheral nerve and C. jejuni (O:19). Conclusions: These data indicate the possible molecular mimicry between the cross-reactive glycoproteins present in C. jejuni and human peripheral nerve and its potential role in the development of GBS following infection with C. jejuni (O:19).

The purpose of this study was to develop and validate a discriminative dissolution method for the metformin film-coated tablet with immediate release of the active substance that belongs to class III of the Biopharmaceutical Classification System (BCS). Different conditions such as type of dissolution medium, volume of dissolution medium, rotation speed, apparatus, and filter suitability were evaluated. The most discriminative release profile for the metformin film-coated tablet was accomplished by using Apparatus II (paddle) and 1000 mL of phosphate buffer pH 6.8 as the dissolution medium and maintained on 37 ± 0.5°C with a rotation speed of 75 rpm. The quantification of the released active substance was performed by UV/Vis spectrophotometry, at 232 nm. Acceptance criteria for not less than 75% (Q) of the labeled content for 45 minutes were set. The dissolution method was validated according to the current international guidelines using the following parameters: specificity, accuracy, precision, linearity, robustness, and stability of the solutions, found to be meeting the predetermined acceptance criteria. A developed dissolution method has discriminatory power to reflect the characteristics of the medicinal product and is able to distinguish any changes related to quantitative formulation and can be also applied for routine batch testing.