The use of Arrhenius kinetics to evaluate different hydrolytic stability of amiloride hydrochloride and cyclopenthiazide using chromatographic methods

Enhanced degradation of amiloride over Bi2FeNbO7/bisulfite process: Key factors and mechanism

Construction of Bi₂FeNbO₇/bisulfite system for abatement of pharmaceutical residue was achieved. An attempt to synthesize Bi₂FeNbO₇ through hydrothermal technique was confirmed by X-ray diffraction. The magnetic field experiment revealed that Bi₂FeNbO₇ possessed a saturation magnetization of 6.99 emu/g, indicating magnetic attributes of Bi₂FeNbO₇. Scanning electron microscopy images showed that Bi₂FeNbO₇ exhibited regular octahedra in the size of 200-300 nm. In a self-made device, the activation of sodium bisulfite using Bi₂FeNbO₇ for the disposal of amiloride has been carefully explored. The effects of solution pH, sodium bisulfite concentration, Bi₂FeNbO₇ dosage, amiloride concentration, coexisting ions, and water matrix on the performance of Bi₂FeNbO₇/bisulfite system was investigated. The catalytic performance of Bi₂FeNbO₇/bisulfite to degrade amiloride was considerably higher than that of traditional iron oxides. The maximum removal efficiency of amiloride was 97.9% in Bi₂FeNbO₇/bisulfite process. The involvement of Fe might be crucial for activating bisulfite to create active species. The dominating radical in Bi₂FeNbO₇/bisulfite process was identified as SO₃^•‒. With the help of UHPLC/MS/MS, three new degradation products of amiloride were found. Dehalogenation and deamination of amiloride might account for the formation of these transformation products. This work provides a highly efficient Bi₂FeNbO₇/bisulfite process for the disposal of pharmaceutical pollutants in water treatment.

Precisely Fabricated Sulpiride-Loaded Nanolipospheres with Ameliorated Oral Bioavailability and Antidepressant Activity

BACKGROUND

Sulpiride (SUL), is a selective antidopaminergic drug that had extensive biological activities. However, its sparingly aqueous solubility and limited gastrointestinal permeability lead to scanty oral bioavailability which hinders its clinical efficacy.

OBJECTIVE

SUL-loaded lipospheres (SUL-LPS) were designed to serve as an oral biocompatible nanovector for improving SUL permeability as well as conquering its low oral absorption and then in turn enhancing its antidepressant action.

METHODS

SUL-LPS were fabricated via two processing techniques namely, melt emulsification and solvent evaporation. The impact of different lipid cores, phospholipid shells together with various surfactant concentrations and types on the lipospheres properties were screened. Detailed physicochemical elucidations were performed followed by ex vivo permeation appraisal using the non-everted intestine model. The pharmacokinetic parameters of SUL-LPS, free SUL and marketed product were assessed following oral administration to healthy rats. Reserpine-induced depression rat model was used to assess the antidepressant action of SUL-LPS on which full behavioural and biochemical analysis was conducted. Safety attributes of nanoencapsulated SUL on the brain and other internal organs were evaluated.

RESULTS

The optimum LPS revealed an excellent nanosize with a narrow PdI, negative zeta potential and acceptable entrapment efficiency of 68.62 nm, 0.242, -30.4 mV and 84.12%, respectively. SUL-LPS showed a sustained release pattern and 2.1-fold enhancement in the intestinal permeation parameters with low mucin interaction. Oral pharmacokinetic appraisal exhibited that LPS provided 3.4-fold improvement in SUL oral bioavailability together with long-circulating properties, relative to the free drug. Pharmacodynamic study confirmed the superior antidepressant action of SUL-LPS as evident by 1.6 and 1.25-fold elevation in the serotonin and dopamine expressions, respectively. Meanwhile, nanotoxicological appraisal proved the biocompatibility of SUL-LPS upon repetitive oral administration.

CONCLUSION

Rationally designed lipospheres hold promising in vitro and in vivo characteristics for efficient delivery of SUL with high oral bioavailability, antidepressant activity together with a good safety profile.

Stability of extemporaneously compounded amiloride nasal spray

Anxiety disorders (AD) are the most common mental conditions affecting an estimated 40 million adults in the United States. Amiloride, a diuretic agent, has shown efficacy in reducing anxious responses in preclinical models by inhibiting the acid-sensing ion channels (ASIC). By delivering amiloride via nasal route, rapid onset of action can be achieved due to direct "nose-to-brain" access. Therefore, this study reports the formulation, physical, chemical, and microbiological stability of an extemporaneously prepared amiloride 2 mg/mL nasal spray. The amiloride nasal spray was prepared by adding 100 mg of amiloride hydrochloride to 50 mL of sterile water for injection in a sterile reagent bottle. A stability-indicating high-performance liquid chromatography (HPLC) method was developed and validated. Forced-degradation studies were performed to confirm the ability of the HPLC method to identify the degradation products from amiloride distinctively. The physical stability of the amiloride nasal spray was assessed by pH, clarity, and viscosity assessments. For chemical stability studies, samples of nasal sprays stored at room temperature were collected at time-points 0, 3 hr., 24 hr., and 7 days and were assayed in triplicate using the stability-indicating HPLC method. Microbiological stability of the nasal spray solution was evaluated for up to 7 days based on the sterility test outlined in United States Pharmacopoeia (USP) chapter 71. The stability-indicating HPLC method identified the degradation products of amiloride without interference from amiloride. All tested solutions retained over 90% of the initial amiloride concentration for the 7-day study period. There were no changes in color, pH, and viscosity in any sample. The nasal spray solutions were sterile for up to 7 days in all samples tested. An extemporaneously prepared nasal spray solution of amiloride hydrochloride (2 mg/mL) was physically, chemically, and microbiologically stable for 7 days when stored at room temperature.