Capturing solubility advantages of cocrystals is of great interest, and thus to understand the mechanism by which different excipients could maintain the supersaturation generated by cocrystals at the course of absorption in aqueous media is essential. To achieve this aim, the impact of different excipients on dissolution behavior of indomethacin−saccharin (IND−SAC) were monitored by measuring the concentrations of cocrystal components in the absence and presence of various concentration of excipients by HPLC, and solid phases were analyzed by differential scanning calorimetry after each experiment and the potential of Raman spectroscopy for monitoring phase transformations in situ was tested. No dissolution advantage was offered by cocrystals in the absence of any solution additive. The polymer and surfactant used in the study increased the solubility of IND but not SAC. This differential solubilization effect is believed to have stabilized the cocrystals for a relevant period for the absorption to take place. This could be attributed to either decreased gap between supersaturation and saturation of the drug or drug interaction with the additives. Understanding the effects of excipients type and concentration on the transformation profile is vital for designing enabling formulations for cocrystals. The eutectic constant may be useful in selecting excipients for stabilizing cocrystals.

The present study investigated the bioaccumulation of organochlorines in two milk-producing animals (goats and cows) grazed on the same feed to explore the extent of organochlorines availability in milk and any species effect on the bioaccumulation pattern. Six organochlorine pesticides: aldrin, -endosulfan, -endosulfan, p,p'-DDE, o,p'-DDT and p,p'-DDT were determined in samples collected from four regions in Ethiopia. Aldrin (11.6 µg kg1) was detected only in one cow milk sample and -endosulfan was detected in one goat milk sample at a level of 142.1 µg kg1, and in one cow milk sample (47.8 µg kg1) from the same region. p,p'-DDE was detected in 40% of the milk samples analyzedwhile o,p'-DDT and p,p'-DDT were found in high amounts in almost all samples. The average total DDT (excluding DDD) in the samples was 328.5 µg kg1. Regions known for their malaria epidemics were the most contaminated with DDT residue. The accumulation pattern in both species was not clear under natural sampling.

Two ultraviolet (UV)–spectrodensitometric methods were proposed for the separation and determination of binary and ternary mixtures containing proton pump inhibitors (PPIs). Method A was developed for the assay of omeprazole, panoprazole, rabeprazole, and lansoprazole in binary mixtures with domperidone (DOM) using their isoabsorptive points. Method B was developed for the determination of a ternary mixture containing omeprazole, tinidazole, and clarithromycin. It depends on using malonic acid–acetic anhydride as a spraying reagent to form yellow color (for omeprazole) and dark brown color (for clarithromycin) that are measured at λmax = 350 nm and λmax = 492 nm, respectively, while tinidazole was measured by UV at λmax = 310 nm. For method A, Beer’s law was obeyed for all studied PPIs and domperidone in the concentration range of 180–1440 and 120–720 ng spot−1, respectively. The detection limits for proton pump inhibitors and domperidone were 48.05–73.45 and 30.74–32.50 ng spot−1, respectively, and the quantitation limits were 145.59–222.47 and 93.14–98.48 ng spot−1, respectively. For method B, Beer’s law was obeyed for omeprazole, clarithromycin, and tinidazole in the concentration range of 180–480, 2250–6000, and 30–180 ng spot−1, respectively. The detection limits for omeprazole, clarithromycin, and tinidazole were 20.36, 272.60, and 2.05 ng spot−1, respectively, and the quantitation limits were 61.7, 825.9, and 6.2 ng spot−1, respectively, for the investigated drugs.

Two ultraviolet (UV)–spectrodensitometric methods were proposed for the separation and determination of binary and ternary mixtures containing proton pump inhibitors (PPIs). Method A was developed for the assay of omeprazole, panoprazole, rabeprazole, and lansoprazole in binary mixtures with domperidone (DOM) using their isoabsorptive points. Method B was developed for the determination of a ternary mixture containing omeprazole, tinidazole, and clarithromycin. It depends on using malonic acid–acetic anhydride as a spraying reagent to form yellow color (for omeprazole) and dark brown color (for clarithromycin) that are measured at λmax = 350 nm and λmax = 492 nm, respectively, while tinidazole was measured by UV at λmax = 310 nm. For method A, Beer’s law was obeyed for all studied PPIs and domperidone in the concentration range of 180–1440 and 120–720 ng spot−1, respectively. The detection limits for proton pump inhibitors and domperidone were 48.05–73.45 and 30.74–32.50 ng spot−1, respectively, and the quantitation limits were 145.59–222.47 and 93.14–98.48 ng spot−1, respectively. For method B, Beer’s law was obeyed for omeprazole, clarithromycin, and tinidazole in the concentration range of 180–480, 2250–6000, and 30–180 ng spot−1, respectively. The detection limits for omeprazole, clarithromycin, and tinidazole were 20.36, 272.60, and 2.05 ng spot−1, respectively, and the quantitation limits were 61.7, 825.9, and 6.2 ng spot−1, respectively, for the investigated drugs.

Two ultraviolet (UV)–spectrodensitometric methods were proposed for the separation and determination of binary and ternary mixtures containing proton pump inhibitors (PPIs). Method A was developed for the assay of omeprazole, panoprazole, rabeprazole, and lansoprazole in binary mixtures with domperidone (DOM) using their isoabsorptive points. Method B was developed for the determination of a ternary mixture containing omeprazole, tinidazole, and clarithromycin. It depends on using malonic acid–acetic anhydride as a spraying reagent to form yellow color (for omeprazole) and dark brown color (for clarithromycin) that are measured at λmax = 350 nm and λmax = 492 nm, respectively, while tinidazole was measured by UV at λmax = 310 nm. For method A, Beer’s law was obeyed for all studied PPIs and domperidone in the concentration range of 180–1440 and 120–720 ng spot−1, respectively. The detection limits for proton pump inhibitors and domperidone were 48.05–73.45 and 30.74–32.50 ng spot−1, respectively, and the quantitation limits were 145.59–222.47 and 93.14–98.48 ng spot−1, respectively. For method B, Beer’s law was obeyed for omeprazole, clarithromycin, and tinidazole in the concentration range of 180–480, 2250–6000, and 30–180 ng spot−1, respectively. The detection limits for omeprazole, clarithromycin, and tinidazole were 20.36, 272.60, and 2.05 ng spot−1, respectively, and the quantitation limits were 61.7, 825.9, and 6.2 ng spot−1, respectively, for the investigated drugs.

A simple, rapid and sensitive spectrofluorimertic method was developed for the determination of certain proton pump inhibitors (PPIs) belonging to benzimidazole drugs omeprazole (OMZ), rabeprazole (RAB), pantoprazole (PAN) and lansoprazole (LAN). The method depends on coupling with sodium 1,2-naphthoquinone-4-sulphonate (NQS) in presence of methanolic solution of iodine and alkaline medium to yield an intensely fluorescent derivative measured at λexc.= 340 nm and λem.= 480 nm. A linear relationship was achieved between measured relative fluorescence intensity and concentration of each of the studied drug in the ranges 5-60, 10-80, 10-65 and 10-85 ng ml-1 for OMZ, LAN, PAN and RAB, respectively with good correlation coefficients. The limits of detection and quantification, intra-day, inter-day precision, and accuracy of the method have been evaluated. The proposed method was successfully applied to the assay of the studied PPIs in dosage forms and the results were statistically agree well with those of reported methods.

A simple, rapid and sensitive spectrofluorimertic method was developed for the determination of certain proton pump inhibitors (PPIs) belonging to benzimidazole drugs omeprazole (OMZ), rabeprazole (RAB), pantoprazole (PAN) and lansoprazole (LAN). The method depends on coupling with sodium 1,2-naphthoquinone-4-sulphonate (NQS) in presence of methanolic solution of iodine and alkaline medium to yield an intensely fluorescent derivative measured at λexc.= 340 nm and λem.= 480 nm. A linear relationship was achieved between measured relative fluorescence intensity and concentration of each of the studied drug in the ranges 5-60, 10-80, 10-65 and 10-85 ng ml-1 for OMZ, LAN, PAN and RAB, respectively with good correlation coefficients. The limits of detection and quantification, intra-day, inter-day precision, and accuracy of the method have been evaluated. The proposed method was successfully applied to the assay of the studied PPIs in dosage forms and the results were statistically agree well with those of reported methods.

A simple, rapid and sensitive spectrofluorimertic method was developed for the determination of certain proton pump inhibitors (PPIs) belonging to benzimidazole drugs omeprazole (OMZ), rabeprazole (RAB), pantoprazole (PAN) and lansoprazole (LAN). The method depends on coupling with sodium 1,2-naphthoquinone-4-sulphonate (NQS) in presence of methanolic solution of iodine and alkaline medium to yield an intensely fluorescent derivative measured at λexc.= 340 nm and λem.= 480 nm. A linear relationship was achieved between measured relative fluorescence intensity and concentration of each of the studied drug in the ranges 5-60, 10-80, 10-65 and 10-85 ng ml-1 for OMZ, LAN, PAN and RAB, respectively with good correlation coefficients. The limits of detection and quantification, intra-day, inter-day precision, and accuracy of the method have been evaluated. The proposed method was successfully applied to the assay of the studied PPIs in dosage forms and the results were statistically agree well with those of reported methods.

The objective of this work was to evaluate liposome-containing gel formulations for the sustained, site-specific delivery of celecoxib (CXB). Liposomes composed of phosphadtidylcholine (and various amounts of cholesterol (Ch) were prepared using thin film hydration and characterized for encapsulation efficiency, vesicle size, and drug-excipient interaction using differential scanning calorimetry and Fourier-transform infrared spectroscopy. The selected liposome formulation was incorporated in different gel formulations: the Ch ratio affected the encapsulation efficiency of the drug, by increasing Ch ratio up until 1:1 the encapsulation efficiency increased. Further increasing the Ch ratio resulted in decreasing encapsulation efficiency. In vitro drug release and skin permeation studies showed sustained release and enhanced permeation compared with gel formulations containing free drug. In the rat paw edema test, the anti-inflammatory activity of the selected liposomal gel formulation was higher and more sustained compared with that of the nonliposomal gel formulation containing free drug. These results suggest that the liposome-containing gels are promising formulations for sustained, site-specific delivery of CXB.

The objective of this work was to evaluate liposome-containing gel formulations for the sustained, site-specific delivery of celecoxib (CXB). Liposomes composed of phosphadtidylcholine (and various amounts of cholesterol (Ch) were prepared using thin film hydration and characterized for encapsulation efficiency, vesicle size, and drug-excipient interaction using differential scanning calorimetry and Fourier-transform infrared spectroscopy. The selected liposome formulation was incorporated in different gel formulations: the Ch ratio affected the encapsulation efficiency of the drug, by increasing Ch ratio up until 1:1 the encapsulation efficiency increased. Further increasing the Ch ratio resulted in decreasing encapsulation efficiency. In vitro drug release and skin permeation studies showed sustained release and enhanced permeation compared with gel formulations containing free drug. In the rat paw edema test, the anti-inflammatory activity of the selected liposomal gel formulation was higher and more sustained compared with that of the nonliposomal gel formulation containing free drug. These results suggest that the liposome-containing gels are promising formulations for sustained, site-specific delivery of CXB.