Formulation and Evaluation of Cephalexin Extended-release Matrix Tablets Using Hydroxy Propyl Methyl Cellulose as Rate-controlling Polymer

The Next Generation COVID-19 Antiviral; Niclosamide-Based Inorganic Nanohybrid System Kills SARS-CoV-2

The coronavirus disease 2019 (COVID-19) pandemic is a serious global threat with surging new variants of concern. Although global vaccinations have slowed the pandemic, their longevity is still unknown. Therefore, new orally administrable antiviral agents are highly demanded. Among various repurposed drugs, niclosamide (NIC) is the most potential one for various viral diseases such as COVID-19, SARS (severe acute respiratory syndrome), MERS (middle east respiratory syndrome), influenza, RSV (respiratory syncytial virus), etc. Since NIC cannot be effectively absorbed, a required plasma concentration for antiviral potency is hard to maintain, thereby restricting its entry into the infected cells. Such a 60-year-old bioavailability challenging issue has been overcome by engineering with MgO and hydroxypropyl methylcellulose (HPMC), forming hydrophilic NIC-MgO-HPMC, with improved intestinal permeability without altering NIC metabolism as confirmed by parallel artificial membrane permeability assay. The inhibitory effect on SARS-CoV-2  replication is confirmed in the Syrian hamster model to reduce lung injury. Clinical studies reveal that the bioavailability of NIC hybrid drug can go 4 times higher than the intact NIC. The phase II clinical trial shows a dose-dependent bioavailability of NIC from hybrid drug  suggesting its potential applicability as a game changer in achieving the much-anticipated endemic phase.

Formulation of Self-Nanoemulsifying Drug Delivery System of Cephalexin: Physiochemical Characterization and Antibacterial Evaluation

A cephalexin (CEP) self-nanoemulsifying drug delivery system (SNEDDS) was developed in this study to improve the drug’s oral administration. The CEP-SNEDDS was made utilizing an aqueous titration method employing Lauroglycol 90, Poloxamer 188, and Transcutol-HP. Box-Behnken design (BBD) with three factors at three levels was used for optimization, and their impacts on globule size (nm), transmittance (percent), and emulsification time (s) were assessed. The optimized formulation (Opt-F3) was further tested for zeta potential, refractive index, percent transmittance, thermodynamic stability, in-vitro release, ex vivo permeability, antibacterial activity, and bioavailability. The chosen formulation (Opt-F3) had a globule size of 87.25 ± 3.16 nm, PDI of 0.25, zeta potential of −24.37 mV, self-emulsification duration of 52 ± 1.7 s, and percentage transmittance of 99.13 ± 1.5%, viscosity of 96.26 ± 2.72 cp, and refractive index of 1.29 ± 0.1. It showed a sustained release profile (94.28 ± 5.92 percent in 24 h). The Opt-F3 formulation had 3.95 times the permeability of CEP-dispersion. In comparison to CEP-dispersion, it also demonstrated greater antibacterial efficacy against tested Gram-positive and Gram-negative pathogens. The oral bioavailability of Opt-F3 is 3.48 times higher than that of CEP-dispersion, according to an in-vivo investigation. It has been determined that the prepared CEP-SNEDDS may be an advantageous carrier for CEP delivery.

Preparation and characterization of a novel thermosensitive and bioadhesive cephalexin nanohydrogel: a promising platform for topical antibacterial delivery

OBJECTIVE

Impetigo is a common and highly contagious bacterial skin infection that mostly affects young children and infants. Herein, we report the development of a thermosensitive and bioadhesive in-situ hydrogel-forming system containing cephalexin-loaded nanoparticles (NPs) suitable for antibacterial drug delivery.

METHODS

The nanohydrogel was formulated using drug-loaded NPs and characterized by its physicochemical characteristics. Antibacterial activities of the cephalexin NPs and nanohydrogel were examined in vitro against Staphylococcus aureus (S. aureus). The ex vivo drug permeation study was performed using rat skin. Finally, this formulation was tested for in vivo antibacterial activity using superficial skin infections in rats.

RESULTS

The mean size and entrapment efficiency of the NPs were found to be 178 nm and 58%, respectively. The transmission electron microscopy analysis verified the formation of spherical NPs. The drug-loaded NPs showed an enhanced eradication effect against S. aureus according to the declined MIC values in comparison with the untreated drug. The ex vivo permeation profile of the cephalexin nanohydrogel showed a slow release pattern for 8 h. When applied on rat skin for 6 days, the nanohydrogel exhibited a superior antibacterial activity with normal hair growth and skin appearance as compared to the plain drug hydrogel.

CONCLUSIONS

These findings suggested that the nanohydrogel could serve as a valuable drug delivery platform against superficial bacterial infections.

Comprehensive review on additives of topical dosage forms for drug delivery

Skin is the largest organ of the human body and plays the most important role in protecting against pathogen and foreign matter. Three important modes such as topical, regional and transdermal are widely used for delivery of various dosage forms. Among these modes, the topical dosage forms are preferred because it provides local therapeutic activity when applied to the skin or mucous membranes. Additives or pharmaceutical excipients (non-drug component of dosage form) are used as inactive ingredients in dosage form or tools for structuring dosage forms. The main use of topical dosage form additives are controling the extent of absorption, maintaining the viscosity, improving the stability as well as organoleptic property and increasing the bulk of the formulation. The overall goal of this article is to provide the clinician with information related to the topical dosage form additives and their current major applications against various diseases.