Development of validated stability-indicating assay methods--critical review.

Development and bioavailability assessment of ramipril nanoemulsion formulation.

Statistics for analytical chemistry

A review with 310 references. Photochemical degradation is likely to be an important loss mechanism for many pharmaceutical pollutants in surface waters. This review summarizes the current knowledge of the photochemical behavior of pharmaceuticals and highlights the use of the fundamental photochemistry and phototoxicity literature to help understand and predict the aquatic fate of pharmaceuticals. Naproxen and diclofenac are shown to exemplify the idea that photochemical behavior obtained from fundamental photochemistry studies can be related to environmental conditions. There are, however, numerous compounds that have been found in environmental matrices for which no photochemistry data relatable to environmental conditions are available. It will be necessary to combine the results available in the large body of fundamental photochemistry and phototoxicity literature with laboratory and field experiments designed to determine direct and indirect photolysis rates and to identify photoproducts. This course will lead to a thorough understanding of the role of photodegradation on the fate and impact of pharmaceutical pollutants.

Photodegradation of pharmaceuticals in the aquatic environment: A review

Ramipril nanoemulsion formulations were successfully prepared by the spontaneous emulsification method (titration method) Sefsol 218 was selected as the oil phase for the development of the formulation on the basis of the solubility studies The differences in the droplet size between the formulations selected from the phase diagram was not statistically significant, although the polydispersity was at a minimum for the formulation containing 20% oil, 27% Smix, and 53% vol/vol aqueous phase The droplet size was found to be 345 nm Therefore, nanoemulsion, a multipurpose technology, can be exploited in drug delivery for poorly soluble drugs Nanoemulsions have a higher solubilization capacity than simple micellar solutions, and their thermodynamic stability offers advantages over unstable dispersions, such as emulsions and suspensions, because they can be manufactured with little energy input (heat or mixing) and have a long shelf life This technical note explains the basis for calculation and construction of pseudoternary phase diagrams and, most important, explains selection of the formulations from the phase diagrams to avoid metastable formulations having minimum surfactant concentration in the least possible time

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Formulation development and optimization using nanoemulsion technique: a technical note.

A stability-indicating LC method for the simultaneous determination of ramipril and hydrochlorothiazide in dosage forms.

Binding of therapeutic agents to plasma proteins, particularly to serum albumin, provides valuable information in the drug development. This study was designed to evaluate the binding interaction of neratinib with bovine serum albumin (BSA). Neratinib blocks HER2 signaling and is effective in trastuzumab-resistant breast cancer treatment. Spectrofluorometric, UV spectrophotometric, and fourier transform infrared (FT-IR) and molecular docking experiments were performed to study this interaction. The fluorescence of BSA is attributed to the presence of tryptophan (Trp) residues. The fluorescence of BSA in presence of neratinib was studied using the excitation wavelength of 280 nm and the emission was measured at 300-500 nm at three different temperatures. Neratinib quenched the BSA intrinsic fluorescence by static mechanism. A complex formation occurred due to the interaction leading to BSA absorption shift. The fluorescence, UV- absorption, three dimensional fluorescence and FT-IR data showed conformational changes occurred in BSA after interaction with neratinib. The binding constant values decreased as the temperature increased suggesting an instable complex formation at high temperature. Site I (sub-domain IIA) was observed as the principal binding site for neratinib. Hydrogen bonding and Van der Waals forces were suggested to be involved in the BSA-neratinib interaction due to the negative values of entropy and enthalpy changes.

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Study of Interactions of an Anticancer Drug Neratinib With Bovine Serum Albumin: Spectroscopic and Molecular Docking Approach.

A highly sensitive fluorimetric method has been developed for the determination of gentamicin. The method is based on its coupling with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) in 50% (v/v) methanolic phosphate buffer (pH 7.2) to give an intensely fluorescent product having excitation and emission wavelengths at 465 nm and 530 nm, respectively. The experimental parameters were carefully studied and incorporated into the procedure. The fluorescence-concentration plot is rectilinear over the range 0.56–2.8 µg/mL (r = 0.999) with minimum detectability (S/N = 2) of 0.11 µg/mL (1.6 × 10−7 mol/L). The method was applied successfully to the determination of the drug in pharmaceutical dosage forms and the percentage recoveries were satisfactorily accurate and precise. The method was further applied to spiked human plasma samples, the percentage recovery was 97.9 ± 3.4. The interference encountered from endogenous amino acids could be eliminated through selective complexation with freshly prepared copper (II) hydroxide. A proposal of the reaction pathway is presented. The method can measure the intact drug, and can be used in presence of possible interference.

Fluorimetric Determination of Gentamicin in Dosage Forms and Biological Fluids Through Derivatization with 4-Chloro-7-Nitrobenzo-2-Oxa-1,3-Diazole (NBD-Cl)

M. A. Abounassif

Papers

A stability-indicating LC method for the simultaneous determination of ramipril and hydrochlorothiazide in dosage forms.

Study of Interactions of an Anticancer Drug Neratinib With Bovine Serum Albumin: Spectroscopic and Molecular Docking Approach.

Fluorimetric Determination of Gentamicin in Dosage Forms and Biological Fluids Through Derivatization with 4-Chloro-7-Nitrobenzo-2-Oxa-1,3-Diazole (NBD-Cl)

Stability studies on some benzocycloheptane antihistaminic agents.

Photodegradation kinetic study and stability-indicating assay of danazol using high-performance liquid chromatography.