Complexity in estimation of esomeprazole and its related impurities' stability in various stress conditions in low-dose aspirin and esomeprazole magnesium capsules

Greenness-sustainability metrics for assessment smart-chemometric spectrophotometric strategy for evaluation of the combination of six gastric proton-pump inhibitors with two selected impurities

Green analytical approaches are employed for the determination of active pharmaceutical ingredients, in conjunction with their impurities. Smart chemometric spectrophotometric techniques, including orthogonal partial least square (OPLS), variable selection such as genetic algorithm (GA-OPLS), and interval selection (i-OPLS), were utilized. These chemometric models were implemented for assessing six proton-pump inhibitors Omeprazole, Esomeprazole, Lansoprazole, Pantoprazole, Rabeprazole, and Dexlansoprazole along with two selected official impurities, namely 4-Desmethoxy omeprazole impurity and Rabeprazole-impurity B. Experimental design was implemented to separate impurities, in the process of multivariate calibration, a five-level eight-factor calibration design consisting of 25 samples was selected. This design was deliberately selected to guarantee that the components were mutually orthogonal to assess the model's performance and reliability, a separate validation set of 15 samples was constructed. The best-performing of the proposed techniques were identified by considering the least favorable values of the Correlation Coefficient (R ≥ 0.9995), the Root Mean Square Error of Prediction (RMSEP) values between (0.0102-0.5622), and the Relative Error of Prediction (REP) values between (0.2961-1.1917). The proposed and reported methods' greenness-sustainability was quantitatively evaluated, and a comparative study of the greenness profile was established through a spider chart, the National Environmental Method Index tool, advanced and modified NEMI along with the Hexagon tool, and the whiteness qualities of the presented approaches were assessed by implementing the recently adopted Red-Green-Blue paradigm and White Analytical Chemistry tool. These approaches are well-suited for use in quality control laboratories due to their observed acceptance, long-term sustainability, simplicity, and affordability.

Aggregated Solution Morphology of Poly(acrylic acid)-Poly(styrene) Block Copolymers Improves Drug Supersaturation Maintenance and Caco-2 Cell Membrane Permeation

Amorphous solid dispersions of polymers and drugs have been shown to improve supersaturation maintenance of poorly water-soluble drugs. Herein, amorphous spray-dried dispersions (SDDs) of poly(acrylic acid)-polystyrene (PS-b-PAA) diblock copolymers with differing degrees of polymerization were prepared in aggregated and nonaggregated states with the Biopharmaceutical Classification System Class II drug, probucol (PBC). Specifically, PS₉₀-b-PAA₁₅, PS₉₀-b-PAA₈₀, PS₃₈-b-PAA₂₂₀, and PS₃₈-b-PAA₃₂₀ amphiphilic block polymers that covered a compositional range in the area of oral drug delivery were prepared to examine the role of molecular weight and controlled aggregation in promoting drug supersaturation and maintenance. In addition, hydrophilic homopolymers PAA₂₀, PAA₉₆, PAA₂₂₆, and PAA₃₉₂ were prepared as controls to evaluate the role of the block copolymer-based SDDs in PBC solubilization. Characterization such as powder X-ray diffraction, scanning electron microscopy, and dissolution tests under nonsink conditions were then performed to evaluate the SDDs. When comparing the block copolymer systems, polymers that were preaggregated into micellular structures prior to spray drying with the drug promoted higher drug solubility and maintenance than when the drug was formulated with molecularly dissolved PS-PAA block polymer. Interestingly, the aggregated PS₉₀-b-PAA₈₀ SDD with 25 wt % PBC achieved 100% burst release and maintained full supersaturation of PBC at pH 6.5 (physiological pH in the small intestine). Dissolution studies conducted at the pH of the stomach (pH = 1.2) show that a minimal amount of drug (∼10 μg/mL) was released, which could be used for protecting drugs from acidic environments (stomach) before reaching the small intestine. To evaluate drug bioavailability, in vitro Caco-2 cell assays were performed, which reveal that PAA-based excipients do not hinder drug permeation across the epithelial membrane and that PS₉₀-b-PAA₈₀ SDD with 25 wt % PBC achieved the highest membrane permeability coefficient. This work demonstrates that block copolymer-based SDDs capable of preaggregating into nanostructures may be a tunable drug-delivery platform that can improve solubility and supersaturation maintenance of Class II pharmaceutics while also not prohibiting bioavailability through model intestinal membranes. Indeed, this concept may be extended to accommodate a myriad of pharmaceutical and excipient structures.

A novel ion-pair RP-HPLC method for simultaneous quantification of naproxen and esomeprazole in pharmaceutical formulations

A rapid, sensitive and stability indicating ion-pair reversed-phase high-performance liquid chromatographic method was developed for simultaneous estimation of naproxen (NPX) and esomeprazole (ESP) in pharmaceutical preparations. In our study, this new method was used to overcome the instability problem of ESP during high-performance liquid chromatographic analysis in the presence of acidic drugs such as NPX. The method was validated according to ICH, FDA and USP guidelines with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity and system suitability. The method was developed by using an isocratic condition of mobile phase comprising buffer [tetrabutylammonium hydroxide (0.0077 M) and n-heptane sulfonic acid-Na salt (0.002 M), pH 7.6], acetonitrile and methanol in a 60 : 20 : 20 v/v/v ratio at a flow rate of 1.5 mL/min over a C-18 (Octadecyl-silica, 5 µm, 250 × 4.6 mm) column at ambient temperature. The recovery for both drugs was found to be >99% which demonstrated the accuracy of this method. Intra- and inter-day precision studies of the new method were less than the maximum allowable limit [% relative standard deviation (RSD) ≤2.0 according to FDA]. The method showed linear response with a correlation coefficient (r(2)) value of 0.999 for both drugs. More importantly, ESP was quite stable in diluting solvent and mobile phase in the presence of NPX for >3 days. Therefore, it was found to be an accurate, reproducible, sensitive and highly stability-indicating method and can be successfully applied for routine analysis of simultaneous assay of NPX and ESP in pharmaceutical dosage forms.