Analytical methods for determination of terbinafine hydrochloride in pharmaceuticals and biological materials

Pollutants in aquatic system: a frontier perspective of emerging threat and strategies to solve the crisis for safe drinking water

Water is an indispensable natural resource and is the most vital substance for the existence of life on earth. However, due to anthropogenic activities, it is being polluted at an alarming rate which has led to serious concern about water shortage across the world. Moreover, toxic contaminants released into water bodies from various industrial and domestic activities negatively affect aquatic and terrestrial organisms and cause serious diseases such as cancer, renal problems, gastroenteritis, diarrhea, and nausea in humans. Therefore, water treatments that can eliminate toxins are very crucial. Unfortunately, pollution treatment remains a difficulty when four broad considerations are taken into account: effectiveness, reusability, environmental friendliness, and affordability. In this situation, protecting water from contamination or creating affordable remedial techniques has become a serious issue. Although traditional wastewater treatment technologies have existed since antiquity, they are both expensive and inefficient. Nowadays, advanced sustainable technical approaches are being created to replace traditional wastewater treatment processes. The present study reviews the sources, toxicity, and possible remediation techniques of the water contaminants.

Analysis of terbinafine in PLGA-based drug delivery systems by a fast and sensitive UHPLC-DAD method

A novel ultra-high performance chromatography method with multichannel detection that allows fast, sensitive, and robust analysis of an antifungal drug terbinafine and its three main impurities β-terbinafine, (Z)-terbinafine, and 4-methylterbinafine in just 5.0 min has been developed. Analysis of terbinafine is important in pharmaceutical analysis since it enables the detection of its impurities at very low concentrations. In this study, we focused on the development, optimization, and validation of the UHPLC method as well as its subsequent application in the evaluation of terbinafine and its three main impurities in the dissolution medium to reveal the incorporation of terbinafine in two poly(lactic-co-glycolic acid) (PLGA) carriers and testing of the drug release at pH 5.5. PLGA based drug delivery systems such as solid dispersions, thin films, microparticles, and nanoparticles are new favorable ways of terbinafine administration. PLGA features excellent tissue compatibility, biodegradation, and adjustable drug release profile. Our pre-formulation study indicates that poly(acrylic acid) branched PLGA polyester has more suitable properties than tripentaerythritol branched PLGA polyester. Therefore, the former is likely to enable design of a new drug delivery system for topically applied terbinafine that could facilitate its administration and increase patient compliance.

α-Cyclodextrin-based poly(pseudo)rotaxane for antifungal drug delivery to the vaginal mucosa

This work aimed to evaluate poly(pseudo)rotaxanes (PPRs) potential for vaginal antifungal delivery. For this, PPRs containing terbinafine (TB) 2 % were obtained using two small surfactants, Kolliphor® RH40 and Gelucire® 48/16, and different α-cyclodextrin (α-CD) concentrations (5 and 10 %). PPRs were characterized by their physicochemical characteristics, irritation, and mucoadhesion capabilities. Formulations' performance was assessed in a vertical penetration model, which uses ex vivo entire porcine vagina. Conventional penetration experiments with excised vaginal tissue were performed as a control. Results showed all formulations were non-irritant according to the HET-CAM test. Furthermore, PPRs with 10 % αCD showed superior mucoadhesion (p < 0.05). Conventional horizontal penetration studies could not differentiate formulations (p > 0.05). However, PPRs with 10 % αCD presented a better performance in vertical ex vivo studies, achieving higher drug penetration into the vaginal mucosa (p < 0.05), which is probably related to the formulation's prolonged residence time. In addition, the antifungal activity of the formulations was maintained against Candida albicans and C. glabrata cultures. More importantly, the formulation's viscosity and drug delivery control had no negative impact on the antifungal activity. In conclusion, the best performance in a more realistic model evidenced the remarkable potential of PPRs for vaginal drug delivery.

Modified Screen-Printed Microchip for Potentiometric Detection of Terbinafine Drugs

The development of miniaturized microchips has widespread and growing interest in manufacturing potentiometric sensors with extremely valuable modifying response characteristics. In this context, here, we demonstrate microfabrication, electrochemical evaluation, and analytical applications of disposable thin-film potentiometric microsensors responsive to terbinafine antifungal medication. Miniaturized microchips have been realized by integration of the sensitive layer membrane modified by carbon nanotubes onto the surface of the plastic screen-printed microchip support using a new approach, which has been recently developed. The sensitive membrane comprises terbinafine HCl: ammonium heptamolybdate complex ion pair as ionophore, o-nitrophenyl octyl ether as a solvent mediator, potassium tetrakis (4-chlorophenyl) borate as an anion excluder, and polyvinyl chloride as support. The microsensor based on this plasticised sensitive membrane provides the Nernstian response and covers a wide concentration range of terbinafine of 10−8–10−2 mole·L−1. The merits offered by the elaborated terbinafine microchip over the bulk-based electrode include reasonable sensitivity (58.5 mV/concentration decade), fast response time (∼30 s.), long-term stability (4 months), integration, and automation feasibility. Furthermore, microfabricated terbinafine chips were successfully applied to the measurements of the investigated medication in some real samples with high accuracy (96.9%) and precision (<3%).

Development of Solvent-Free Co-Ground Method to Produce Terbinafine Hydrochloride Cyclodextrin Binary Systems; Structural and In Vitro Characterizations

Molecular complexation with cyclodextrins (CDs) has long been a known process for modifying the physicochemical properties of problematic active pharmaceutical ingredients with poor water solubility. In current times, the focus has been on the solvent-free co-grinding process, which is an industrially feasible process qualifying as a green technology. In this study, terbinafine hydrochloride (TER), a low solubility antifungal drug was used as a model drug. This study aimed to prepare co-ground products and follow through the preparation process of the co-grinding method in the case of TER and two amorphous CD derivatives: (2-hydroxypropyl)-β-cyclodextrin (HPBCD); heptakis-(2,6-di-O-methyl)-β-cyclodextrin (DIMEB). For this evaluation, the following analytical tools and methods were used: phase solubility studies, differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), hot-stage X-ray powder diffractometry (HOT-XRPD), Fourier-transform infrared (FT-IR), Raman spectroscopy, and Scanning Electron Microscopy (SEM). Furthermore, in vitro characterization (dissolution and diffusion studies) was performed in two kinds of dissolution medium without enzymes. In the XRPD and SEM studies, it was found that the co-grinding of the components resulted in amorphous products. FT-IR and Raman spectroscopies confirmed the formation of an inclusion complex through the unsaturated aliphatic chain of TER and CDs. In vitro characterization suggested better dissolution properties for both CDs and decreased diffusion at higher pH levels in the case of HPBCD.

Investigating the interaction of terbinafine with xanthenes dye for its feasible determination applying the resonance Rayleigh scattering technique

Terbinafine hydrochloride is a potent antifungal drug indicated for oral and topical treatment of mycoses. A resonance Rayleigh scattering (RRS) method was developed for the determination of terbinafine hydrochloride through a feasible complexation reaction with erythrosine B. In a weakly acidic medium (acetate buffer, pH 5.0), terbinafine hydrochloride can react with erythrosine B through the electrostatic attraction and virtue of hydrophobic force to form an ion-association complex. The reaction resulted in the appearance of a new RRS peak at 369 nm. The RRS peak was increased by increasing the concentration of terbinafine hydrochloride in the linear range of 0.1-1.5 µg ml-1. All the reaction conditions (erythrosine B concentration, buffer volume, diluting solvent and pH) were optimized. The detection limit was 0.029 µg ml-1 while the quantitation limit was 0.089 µg ml-1. The suggested method after its validation was successfully applied for the determination of terbinafine hydrochloride in different pharmaceutical formulations (tablets and cream) with sufficient recovery.

New approaches to identification and characterization of tioconazole in raw material and in pharmaceutical dosage forms

Tioconazole (TCZ), a broad-spectrum antifungal agent, has significant activity against Candida albicans and other Candida species, and therefore, it is indicated for the topical treatment of superficial mycoses. The main goal of this work is to report an exhaustive identification and characterization procedure to improve and facilitate the online quality control and continuous process monitoring of TCZ in bulk material and loaded in two different dosage forms: ovules and nail lacquer. The methodologies were based on thermal (differential scanning calorimetry (DSC), melting point, and thermogravimetry (TG)), spectroscopic (ultraviolet (UV), Raman, near infrared (NIR), infrared spectroscopy coupled to attenuated total reflectance (FTIR-ATR), and nuclear magnetic resonance (NMR)), microscopic and X-ray diffraction (XRD). The TCZ bulk powder showed a high crystallinity, as observed by XRD, with a particles size distribution (3-95 µm) resolved by microscopic measurements. TCZ melting point (82.8 °C) and a degradation peak centered at 297.8 °C were obtained by DSC and DTG, respectively. An unambiguous structure elucidation of TCZ was obtained by mono- and two- dimensional 1H and 13C NMR spectral data analysis. The FTIR-ATR, Raman and NIR spectra of both the raw material and the commercial products were analyzed and their characteristic bands were tabulated. The best methods for TCZ identification in ovules were DSC, TG, XRD, NIR and Raman, while NIR and FTIR-ATR were the most appropriate techniques to analyze it in the nail lacquer. DSC, TG, DRX, Raman, FTIR-ATR and NIR spectroscopy are effective techniques to be used in online process analysis, because they do not require sample preparation, and they are considerably sensitive to analyze complex samples.