A simple and sensitive high-performance liquid chromatography method for determination of ciprofloxacin in bioavailability studies of conventional and gastroretentive prolonged-release formulations

QbD-Engineered Development and Validation of a RP-HPLC Method for Simultaneous Estimation of Rutin and Ciprofloxacin HCl in Bilosomal Nanoformulation

In the given study, a new reverse-phase high-performance liquid chromatography (RP-HPLC) method has been reported for the simultaneous estimation of ciprofloxacin hydrochloride (CPX) and rutin (RUT) using quality by design (QbD) approach. The analysis was carried out by applying the Box-Behnken design having fewer design points and less experimental runs. It relates between factors and responses and gives statistically significant values, along with enhancing the quality of the analysis. CPX and RUT were separated on the Kromasil C₁₈ column (4.6 × 150 mm, 5 μm) using an isocratic mobile phase combination of phosphoric acid buffer (pH 3.0) and acetonitrile with the ratio of 87:13% v/v at a flow rate of 1.0 mL/min. CPX and RUT were detected at their respective wavelengths of 278 and 368 nm using a photodiode array detector. The developed method was validated according to guideline ICH Q2 R (1). The validation parameters taken were linearity, system suitability, accuracy, precision, robustness, sensitivity, and solution stability which were in the acceptable range. The findings suggest that the developed RP-HPLC method can be successfully applied to analyze novel CPX-RUT-loaded bilosomal nanoformulation prepared by thin-film hydration technique.

A Comprehensive Study of a New 1.75 Hydrate of Ciprofloxacin Salicylate: SCXRD Structure Determination, Solid Characterization, Water Stability, Solubility, and Dissolution Study

One problem that often arises during the formulation of a dosage form is the solubility and dissolution of the active ingredients. This problem arises in ciprofloxacin, which is a BCS class IV fluoroquinolone antibiotic. A pseudopolymorph is a kind of polymorph in which the number of hydrates is different. In this study, a new pseudopolymorph comprised of ciprofloxacin and salicylic acid was found, namely the salt ciprofloxacin salicylate 1.75 hydrate form. This new solid phase was analyzed by Fourier-transform infrared spectroscope (FTIR), Raman spectroscopy, and thermal analysis and proven by Powder X-ray Diffractometry (PXRD) analysis. The crystal structure was successfully determined by Single Crystal X-ray Diffractometry (SCXRD) analysis. It was found that the piperazinyl group of ciprofloxacin is protonated by H+ from the carboxylic group of salicylic acid. In the unit cell, two ciprofloxacin and two salicylic acid molecules were independent with four water molecules, in which one water molecule had 0.5 occupancy due to inversion symmetry. Interestingly, this hydrate crystal dehydrated by grinding for 105 minutes forms an anhydrous crystalline phase, which was analyzed with FTIR, Raman spectroscopy, thermal analysis, and PXRD. The solubility and dissolution tests were carried out using UV-Visible spectrophotometry and a multiple linear regression method. This new hydrate solid phase has a better profile than the original ciprofloxacin crystal, according to the solubility and dissolution tests.

Cetyltrimethylammonium Bromide (CTAB) Bloated Micelles and Merged CTAB/Bolaamphiphiles Self-Assembled Vesicles toward the Generation of Highly Porous Alumina as Efficacious Inorganic Adsorbents

Herein, in a new approach, highly porous alumina materials (HiPAs) have been synthesized through cetyltrimethylammonium bromide (CTAB) bloated micelles or merged CTAB/dicarboxylic acid vesicular aggregates (di-acids with 8, 10, and 12 carbon atoms) as novel templates and characterized by N₂ sorption, low- and wide-angle XRD (X-ray diffraction), FE-SEM (field emission scanning electron microscopy), TEM (transmission electron microscopy), HR-TEM (high-resolution transmission electron microscopy), DLS (dynamic light scattering), and AFM (atomic force microscopy) analyses. In the absence of dicarboxylic acids, CTAB bloated micelles in ethanol-aqueous solutions were conductive to the formation of mesoporous γ-alumina hollow spheres (HiPA-CT) with high surface area (394 m² g^-1) and ultralarge pore volume (1.8 cm³ g^-1). Notably, merged giant vesicular assemblies formed between dicarboxylic acids and CTAB endowed the mesoporous alumina nanoparticle aggregates with tunable and unprecedented pore features (surface area of 415-735 m² g^-1 and ultrahigh pore volume of 1.37-2.57 cm³ g^-1), in which their pinnacle was obtained via CTAB/10 (HiPA-CT-10). Due to the tailored porosity, the HiPA-CT and HiPA-CT-10 were exploited for ciprofloxacin (CIP) adsorption experiments. The adsorption efficiency attained a climax at pH 6. At CIP concentrations below 1 ppm, 91 and 86% of CIP were removed by HiPA-CT and HiPA-CT-10, respectively. The maximum adsorption capacities of HiPA-CT and HiPA-CT-10 are 120 and 184 mg g^-1, respectively, in which the latter is surpassing those of inorganic antibiotic adsorbents reported so far. The kinetic results showed that the removal of CIP by HiPA-CT was faster due to the presence of macropores and more accessible active sites on mesoporous surfaces. The reusability test was acceptable after eight runs. The results signify that these novel materials have high potential for reducing our environmental concerns.