In situ Gel of Metoprolol Tartrate: Physicochemical Characterization, In vitro Diffusion and Histological Studies

Hydrogel dressing composed of nanoAg@QAC promotes the healing of bacterial infected diabetic wounds

Diabetes mellitus ranks as the eighth most prevalent cause of mortality and disability worldwide. It is a major challenge for clinics to treat diabetic-infected wounds. The hydrogel (referred to as NanoAg@QAC), which combines the advantages of nanosilver (NanoAg) and quaternary ammonium chitosan (QAC), possesses the characteristics of an ideal wound dressing, including proper mechanical properties, antimicrobial activity, anti-biofilm properties, and cytocompatibility. The NanoAg@QAC hydrogel proved to be efficacious in treating infections caused by S. aureus and P. aeruginosa in vivo, thereby promoting wound closure during the initial phase of healing. The application of the NanoAg@QAC hydrogel efficiently suppressed M1-type macrophage marker iNOS expression and simultaneously enhanced the M2-type macrophage marker CD206, which promoted the M1 to M2 transition. The hydrogel significantly reduced the pro-inflammatory cytokine interleukin-1β (IL-1β) and increased the levels of vascular endothelial growth factor A (VEGFA), which alleviated the inflammatory response of the wound and promoted neovascularization. Furthermore, the NanoAg@QAC hydrogel enhanced tissue regeneration and collagen deposition. Thisw study demonstrates that the NanoAg@QAC hydrogel exhibits significant potential for application in the treatment of diabetic-infected wounds.

Recent advances in the synthesis of highly substituted imidazolidines

Imidazolidine is a saturated heterocycle with a cyclic aminal core that can be found in natural products and biologically active molecules. Additionally, these heterocyclic compounds have been utilized as chiral ligands, N-heterocyclic carbene precursors, and catalysts in organic synthesis. This review is an attempt to compile the literature of various synthetic procedures of highly substituted imidazolidines, chiral imidazolidines with high diastereoselectivities and enantioselectivities, bis-imidazolidines, and spiro-imidazolidines, as well as their pharmacological properties during the period from 1949 to 2023.

Review of Intranasal Active Pharmaceutical Ingredient Delivery Systems

In recent decades, there has been an increased interest in the development of intranasal delivery systems for active pharmaceutical ingredients (APIs) not only for treating local nasal diseases but also for treating systemic diseases, central nervous system (CNS) disorders, and vaccine delivery. The nasal cavity possesses a unique set of anatomical characteristics for delivering active pharmaceutical ingredients, but there are several limitations that recent research in the field of the intranasal administration of APIs aims to overcome. For the effective delivery of nasal preparations, active pharmaceutical ingredients are incorporated into various micro- and nanosystems. Some of the most commonly encountered API delivery systems in the scientific literature include liposomal systems, polymer particles with mucoadhesive properties, in situ gels, nano- and microemulsions, and solid lipid particles. This article provides a review of research on the development of nasal preparations for treating local nasal cavity diseases (in particular, for antibiotic delivery), systemic diseases (analgesics, drugs for cardiovascular diseases, antiviral and antiemetic drugs), CNS disorders (Alzheimer's disease, Parkinson's disease, epilepsy, schizophrenia, depression), and vaccine delivery. The literature data show that active research is underway to reformulate drugs of various pharmacotherapeutic groups into a nasal form.

Pullulan and Pluronic F-127 based in situ gel system for intranasal delivery: Development, in vitro and in vivo evaluation

The current work seeks to use Pullulan and Pluronic F-127 (PF-127), a new gel-forming material, for sildenafil citrate (SLC) intranasal delivery. The cold approach was used to develop an SLC-loaded in situ gel based on thermoreversible polymer PF-127 and mucoadhesive polymer Pullulan. In situ gel systems based on Pullulan responds intelligently to environmental stimuli like charge, pH, temperature, light, and redox. To achieve gelation at physiological temperature formulations were modified to have gelation temperatures lower than 34.1°C. Physical appearance and rheological measurements were used to calculate the temperature of gelation. With the addition of increasing quantities of Pullulan, the gelation temperatures fell (from 34.1°C for 8% w/v, 10% w/v, and 12% w/v 0.5% Pullulan). In the goat nasal mucosal membrane, Pullulan concentration increased the mucoadhesive force in terms of detachment stress. The results of drug permeation testing in vitro investigations over the goat nasal mucosa showed that utilizing an in situ gelling formulation with a Pullulan content of 0.5% or higher can greatly boost the effective penetration coefficient. The formulation was shown to be safe for the nasal mucosa after a histological investigation. Conclusively, Pullulan and PF-127 may be appropriate carriers for SLC intranasal administration.

In vitro and ex vivo studies on diltiazem hydrochloride-loaded microsponges in rectal gels for chronic anal fissures treatment

Diltiazem hydrochloride, topically applied at 2% concentration, is considered effective for the treatment of chronic anal fissures, although it involves several side effects among which anal pruritus and postural hypotension. To test the hypothesis that a sustained delivery system of diltiazem hydrochloride may be helpful for the treatment of chronic anal fissures, in the present study we evaluated the potential of gels containing diltiazem hydrochloride entrapped in microsponges. Such microsponges were based on Eudragit RS 100 and the effect of some formulation variables was assessed by a 2³ full factorial screening design. An optimized formulation of diltiazem hydrochloride microsponges was dispersed in Methylcellulose 2% or Poloxamer 407 20% and the resulting gels (micro-l-diltiazem hydrochloride 2%) were subjected to in vitro drug release, ex vivo permeability and drug deposition after application on porcine rectal mucosa. The results showed a prolonged release up to 24 h from micro-l-diltiazem hydrochloride at 2% in the gels. The permeation tests revealed up to 18% higher drug retention on the mucosal tissue after 24 h by the micro-l-diltiazem hydrochloride 2% gels compared to conventional diltiazem hydrochloride gels at 2%. These results suggest that diltiazem hydrochloride-loaded microsponges dispersed in rectal gels may be useful to overcome some limitations of conventional local chronic anal fissure therapy.

Intranasal chitosan-g-HPβCD nanoparticles of efavirenz for the CNS targeting

Incompetence of antiretrovirals (ARV) in complete eradication of HIV from the CNS is the biggest issue in neuro-AIDS treatment. The ineffectiveness is largely due to the poor penetration of ARV. Hence, the present study is attempted to enhance the CNS uptake of efavirenz (EFV) by designing intranasal EFV nanoparticles (EFV-NPs). EFV-NPs were fabricated using chitosan-g-HPβCD by ionic gelation method and optimized using quadratic response surface methodology (RSM) employing two-factor, five-level circumscribed central composite design. NPs containing drug: polymer ratio (1.25:0.79) were spherical with 198 ± 4.4 nm size, 23.28 ± 1.5% drug loading and 38 ± 1.43% entrapment efficiency. NPs showed sustained drug release (99.03 ± 0.30% in 8 h) and followed Fickian diffusion mechanism. It gave 4.76 times greater permeability than plain drug solution through porcine nasal mucosa. Enhanced CNS bioavailability (12.40-fold that of i.v solution) of EFV, high drug-targeting percentage (99.24%) and drug-targeting index (141.3) post-intranasal administration of NPs was observed. These results are corroborated by gamma scintigraphy images, which revealed high CNS uptake. NPs appeared histocompatible with porcine nasal mucosa and non-toxic to L929 cell line. Thus, CS-g-HPβCD served as a potential carrier in developing intranasal mucoadhesive EFV-NPs for the CNS targeting.

Synthesis and tripanocidal activity of ferrocenyl and benzyl diamines against Trypanosoma brucei and Trypanosoma cruzi

Trypanosoma brucei and Trypanosoma cruzi are the etiologic agents of sleeping sickness and Chagas disease, respectively, two of the 17 preventable tropical infectious diseases (NTD) which have been neglected by governments and organizations working in the health sector, as well as pharmaceutical industries. High toxicity and resistance are problems of the conventional drugs employed against trypanosomiasis, hence the need for the development of new drugs with trypanocidal activity. In this work we have evaluated the trypanocidal activity of a series of N1,N2-dibenzylethane-1,2-diamine hydrochlorides (benzyl diamines) and N1-benzyl,N2-methyferrocenylethane-1,2-diamine hydrochlorides (ferrocenyl diamines) against T. brucei and T. cruzi parasite strains. We show that incorporation of the ferrocenyl group into the benzyl diamines increases the trypanocidal activity. The molecules exhibit potential trypanocidal activity in vitro against all parasite strains. Cytotoxicity assay was also carried out to evaluate the toxicity in HepG2 cells.