A stability-indicating HPLC method for estimation of doxylamine succinate in tablets and characterization of its major alkaline stress degradation product

Background

A new selective rapid RP-HPLC-DAD method was developed and evaluated for the quantification of doxylamine succinate (DOX) in bulk and pharmaceutical dosage form. The separation of DOX at different degradation conditions was achieved with a Kromasil C18 (4.6 × 250 mm, 5-μm particle size). The mobile phase employed comprised of phosphate buffer (pH 3.5) and methanol in the ratio of 45:55 v/v. The flow rate was kept maintained at 1.0 ml/min and eluents were detected at 262 nm. The drug was subjected to different stress conditions like acid, base, neutral, hydrolysis, oxidation, photolysis, and thermal degradation. The analytical performance of the proposed HPLC method was thoroughly validated in terms of linearity, precision, accuracy, specificity, robustness, detection, and quantification limits.

Results

The method produces linear responses that were found in the range of 10–50 μg/ml. The regression equation was found to be Y = 42984x − 10260. The correlation coefficient was found to be 0.9998. The LOD and LOQ for DOX were found to be 0.96 and 3.28 μg/ml, respectively. The short-term solution stability of DOX (100 μg/ml) was evaluated under (25 ± 2°C) storage condition and found to be 98.82 to 101%. The percentage recovery for DOX was in the range of 99.73 to 99.91%. The obtained results of the stress degradation study and peak purity data indicate the potential of the developed HPLC method to resolve degradants from DOX peak. The major alkaline degradation product was isolated using preparative chromatographic technique and extensive FT-IR was performed to ascertain the structure of the alkaline degradant.

Conclusion

It was concluded that the proposed method was simple, sensitive, accurate, cost-effective, and less time-consuming for the quantification of DOX. This method was successfully utilized for stability testing of commercially available DOX tablets. Hence, the proposed method can be applied for routine quality control of DOX in bulk drug as well as in marketed formulations.

Protocatechuic acid attenuates chronic unpredictable mild stress induced-behavioral and biochemical alterations in mice

Amelioration of oxidative stress via promoting the endogenous antioxidant system and enhancement of monoamines in brain were the important underlying antidepressant mechanism of protocatechuic acid (PCA). The aim of the present study is to explore the potential antidepressant mechanism(s) PCA in chronic unpredictable mild stress (CUMS) mice. Mice were subjected to CUMS protocol for 4 weeks, and administered with PCA (100 and 200 mg/kg) and fluoxetine (20 mg/kg) for 24 days (from day 8th to 31st). Behavioral (sucrose preference, immobility time, exploratory behavior), and biochemical alterations such as serum corticosterone, brain derived neurotrophic factor (BDNF), inflammatory cytokines, tumor necrosis factor- α (TNF-α), interleukin-6 (IL-6), and antioxidants parameters were investigated. Experimental findings revealed that CUMS subjected mice exhibited significant impairment in behavioral alterations, such as increased immobility time, impaired preference to the sucrose solution, BDNF levels and, serum corticosterone, cytokines, malondialdehyde (MDA) formation with impaired antioxidants in the hippocampus and cerebral cortex. Administration of PCA to CUMS mice attenuated the immobility time, serum corticosterone, cytokines TNF-α, and IL-6, MDA formation and improved sucrose preference, including restoration of BDNF level. Thus, the present findings demonstrated the antidepressant potential of PCA which is largely achieved probably through maintaining BDNF level, and by modulation of the oxidative stress response, cytokines systems, and antioxidant defense system in mice.

Facile synthesis of multi-walled carbon nanotube via folic acid grafted nanoparticle for precise delivery of doxorubicin

The motive of work was to develop a multi-walled carbon nanoplatform through facile method for transportation of potential anticancer drug doxorubicin (DOX). Folic acid (FA)-ethylene diamine (EDA) anchored and acid functionalised MWCNTs were covalently grafted with DOX via π-π stacking interaction. The resultant composite was corroborated by ¹H NMR, FTIR, XRD, EDX, SEM, and DSC study. The drug entrapment efficiency of FA-conjugated MWCNT was found high and stability study revealed its suitability in biological system. FA-EDA-MWCNTs-DOX conjugate demonstrated a significant in vitro anticancer activity on human breast cancer MCF-7 cells. MTT study revealed the lesser cytotoxicity of folate-conjugated MWCNTs. The obtained results demonstrated the targeting specificity of FA-conjugate via overexpressed folate receptor deemed greater scientific value to overcome multidrug protection during cancer therapy. The proposed strategy is a gentle contribution towards development of biocompatible targeted drug delivery and offers potential to address the current challenges in cancer therapy.

Facile synthesis of mesoporous alumina using hexadecyltrimethylammonium bromide (HTAB) as template: simplified sol-gel approach

Herein the authors present the synthesis of surface functionalised mesoporous alumina (MeAl) for textural characterisation by a simplified sol-gel method obtained by using hexadecyltrimethylammonium bromide as a template. Etoricoxib (ETOX) was used as a model drug for the study. Alumina supported mesoporous material containing drug was characterised using instrumental technique namely Brunauer-Emmett-Teller surface area, Fourier transform-infrared, differential scanning calorimetry, transmission electron microscopy, X-ray diffraction, and field emission scanning electron microscopy. Diffusion study using a dialysis bag method used to check the release pattern of ETOX-loaded-MeAl. Results of characterisation study revealed the successful surface functionalisation of the drug on nanocomposite. The IC50 value obtained from cell viability study demonstrated the non-toxic behaviour of synthesised drug-loaded mesoporous alumina up to the tested concentration range. The present work has demonstrated that synthesised MeAl showed excellent stability with an expanded surface area suitable for carrier material for drug delivery system.