Hydrogels and Their Combination with Liposomes, Niosomes, or Transfersomes for Dermal and Transdermal Drug Delivery

Polymeric networks that retain and absorb substantial amount of water or biological fluids and resemble as a biological tissue are defined as hydrogels. On the other hand, liposomes, transfersomes and niosomes are lipid carriers, which represent one of the major research and development focus areas of the pharmaceutical industry. They have great potential as lipid vehicles that are able to enhance permeation of drugs across the intact skin and can act as local depot for the drug to sustain and control its delivery. Lipid carrier and hydrogel combinations offer transdermal drug delivery of great potential to enhance systemic effects of both hydrophilic and lipophilic drugs. Also, lipid carriers can target drugs to skin appendages and improve transdermal delivery. Lipid carrier proform systems in the form of gelly liquid crystals can also be used transdermally for better drug absorption enhancement. This review highlights the potential of hydrogels and emulgels with or without lipid nanocarriers for dermal and transdermal application

Evaluation of Halogenated Coumarins for Antimosquito Properties

Mosquitoes are the major vectors of parasites and pathogens affecting humans and domestic animals. The widespread development of insecticide resistance and negative environmental effects of most synthetic compounds support an interest in finding and developing alternative products against mosquitoes. Natural coumarins and synthetic coumarin analogues are known for their several pharmacological properties, including being insecticidal. In the present study halogenated coumarins (3-mono/dibromo acetyl, 6-halogenated coumarin analogues) were screened for larvicidal, adulticidal, and repellent properties against Anopheles arabiensis, a zoophilic mosquito that is one of the dominant vectors of malaria in Africa. Five compounds exerted 100% larval mortality within 24 h of exposure. All coumarins and halogenated coumarins reversibly knocked down adult mosquitoes but did not kill them after 24 h of exposure. Repellent properties could not be evidenced. Five compounds were considered potential larvicidal agents for further research and development, while adulticidal activity was considered only mild to moderate

Development of Novel Unfolding Film System of Itopride Hydrochloride Using Box-Behnken Design—A Gastro Retentive Approach

Currently, gastro-retentive dosage forms achieved a remarkable position among the oral drug delivery systems. This is a broadly used technique to hold the drug delivery systems for a long duration in the gastro intestine (GI) region, slow drug delivery, and overcome other challenges related to typical oral delivery such as low bioavailability. The current work aimed to formulate and characterize a new expandable gastro-retentive system through Itopride Hydrochloride (IH)’s unfolding process for controlled release. The IH-loaded unfolding film formulation was optimized using the Box-Behnken design for folding endurance and length of tested layer (LTL). Initially, the formulation was made using several anti-adhesive additives to promote the unfolding mechanism. Citric acid and sodium bicarbonate were selected as anti-adhesives based on these results. The enfolded film in a capsule shell was shown to unroll in the stomach fluids and render drug delivery up to 12 h in acidic conditions. A fabricated system should have dimensions more than the size of the relaxed pyloric sphincter, and as required, >20 mm LTL was identified. This further confirms that the residence period in the stomach is irrelevant to the fed or fasted condition. Based on desirability criteria, the formulation containing 143.83, 0.7982, and 14.6096 Eudragit L100, PEG, and sodium bicarbonate are selected as optimized formulations (O-IH-UF). The optimized formulation was further analyzed for various parameters such as tensile strength, mechanical strength, unfolding nature, degradability, and in vitro release studies. The pharmacokinetic study revealed greater AUC (area under the curve) and long half-life with the designed O-IH-UF formulation, confirming that the unfolding film type can be a favorable drug system for enhancing the bioavailability of low soluble drugs. The results showed that unfolding types of gastro retentive systems could potentiate the drugs with stability issues in an alkaline medium or those with absorption in acidic conditions

Molecular modeling studies and anti-TB activity of trisubstituted indolizine analogues; molecular docking and dynamic inputs

<p>A series of trisubstituted indolizine analogues has been designed as a result of a fragment-based approach to target the inhibition of mycobacterial enoyl-acyl carrier protein reductase. Anti-tuberculosis (TB) screening of the characterized compounds by a resazurin microplate assay method revealed that ethyl group at second position of indolizine nucleus exhibited activity against susceptible and multidrug-resistant strains of <i>Mycobacterium tuberculosis</i> at concentration of 5.5 and 11.3 μg/mL, respectively. A molecular docking study was also conducted to evaluate the stability of the active compounds, and compound with ethyl substitution at second position of indolizine nucleus showed the highest free binding energy of Δ<i>G</i> −24.11 (kcal/mol), a low clash score of 3.04, and high lipo score of −13.33. Indolizine analog with ethyl substitution at second position demonstrated Molecular Mechanics/Generalized Born Surface Area (−23.85 kcal/mol). Two molecular dynamics studies were computed (100 ps and 50 ns) to calculate the relationship between the potential and kinetic energies of the active anti-TB compound with time and temperature. The discovery of this lead may have a positive impact on anti-TB drug discovery.</p

Computational Design, Synthesis, and Pharmacological Evaluation of Naproxen-Guaiacol Chimera for Gastro-Sparing Anti-Inflammatory Response by Selective COX2 Inhibition

The 4-allyl guaiacol is a natural phenolic molecule that has been widely studied for its antioxidant capacity against reactive-oxygen-species-mediated cellular damage. Therefore, we hypothesized that concomitant use of an antioxidant and NSAID may decrease the risk of gastrointestinal toxicity and make the therapy safer. To address the gastrointestinal toxicity of conventional NSAIDs, a new S-naproxen-4-allyl guaiacol chimera (MAS-1696) was computationally developed, chemically synthesized, and tested for anti-inflammatory effectiveness and gastrointestinal safety. The inhibitory potency of MAS-1696 tested against cyclooxygenase-2 (COX2), 15-lipoxygenase-2 (15-LOX2), and lipoxygenase-5 (5-LOX) in vitro revealed a stronger inhibition of COX2. Furthermore, the MAS-1696 chimera increased the COX selectivity index by 23% as compared to the parent compound naproxen, implying higher efficacy and gastric safety. In vivo data showed that MAS-1696 was less likely to cause gastrointestinal harm than naproxen while also exerting anti-inflammatory and analgesic effects equivalent to or superior to naproxen. In conclusion, MAS-1696 is orally active, bio-labile, and crystalline, making it a medication that may be administered orally

Novel Series of Methyl 3-(Substituted Benzoyl)-7-Substituted-2-Phenylindolizine-1-Carboxylates as Promising Anti-Inflammatory Agents: Molecular Modeling Studies

The cyclooxygenase-2 (COX-2) enzyme is considered to be an important target for developing novel anti-inflammatory agents. Selective COX-2 inhibitors offer the advantage of lower adverse effects that are commonly associated with non-selective COX inhibitors. In this work, a novel series of methyl 3-(substituted benzoyl)-7-substituted-2-phenylindolizine-1-carboxylates was synthesized and evaluated for COX-2 inhibitory activity. Compound 4e was identified as the most active compound of the series with an IC50 of 6.71 &mu;M, which is comparable to the IC50 of indomethacin, a marketed non-steroidal anti-inflammatory drug (NSAID). Molecular modeling and crystallographic studies were conducted to further characterize the compounds and gain better understanding of the binding interactions between the compounds and the residues at the active site of the COX-2 enzyme. The pharmacokinetic properties and potential toxic effects were predicted for all the synthesized compounds, which indicated good drug-like properties. Thus, these synthesized compounds can be considered as potential lead compounds for developing effective anti-inflammatory therapeutic agents

Computational, crystallographic studies, cytotoxicity and anti-tubercular activity of substituted 7-methoxy-indolizine analogues.

Indolizines are heteroaromatic compounds, and their synthetic analogues have reportedly showed promising pharmacological properties. In this study, a series of synthetic 7-methoxy-indolizine derivatives were synthesised, characterised and evaluated for in vitro whole-cell anti-tuberculosis (TB) screening against susceptible (H37Rv) and multi-drug-resistant (MDR) strains of Mycobacterium tuberculosis (MTB) using the resazurin microplate assay method. The cytotoxicity was evaluated using the MTT assay. In silico molecular-docking study was conducted for compounds 5a-j against enoyl-[acyl-carrier] protein reductase, a key enzyme of the type II fatty acid synthesis that has attracted much interest for the development of novel anti-TB compounds. Thereafter, molecular dynamic (MD) simulation was undertaken for the most active inhibitors. Compounds 5i and 5j with the methoxy functional group at the meta position of the benzoyl group, which was at the third position of the indolizine nucleus, demonstrated encouraging anti-TB activity against MDR strains of MTB at 16 μg/mL. In silico studies showed binding affinity within the range of 7.07-8.57 kcal/mol, with 5i showing the highest binding affinity. Hydrogen bonding, π-π- interactions, and electrostatic interactions were common with the active site. Most of these interactions occurred with the catalytic amino acids (Pro193, Tyr158, Phe149, and Lys165). MD simulation showed that 5j possessed the highest binding affinity toward the enzyme, according to the two calculation methods (MM/PBSA and MM/GBSA). The single-crystal X-ray studies of compounds 5c and 5d revealed that the molecular arrangements in these two structures were mostly guided by C-H···O hydrogen-bonded dimeric motifs and C-H···N hydrogen bonds, while various secondary interactions (such as π···π and C-H···F) also contributed to crystal formation. Compounds 5a, 5c, 5i, and 5j exhibited no toxicity up to 500 μg/mL. In conclusion, 5i and 5j are promising anti-TB compounds that have shown high affinity based on docking and MD simulation results

Crystallography, in Silico Studies, and In Vitro Antifungal Studies of 2,4,5 Trisubstituted 1,2,3-Triazole Analogues

A series of 2,4,5 trisubstituted-1,2,3-triazole analogues have been screened for their antifungal activity against five fungal strains, Candida parapsilosis, Candida albicans, Candida tropicalis, Aspergillus niger, and Trichophyton rubrum, via a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) microdilution assay. Compounds GKV10, GKV11, and GKV15 emerged as promising antifungal agents against all the fungal strains used in the current study. One of the highly active antifungal compounds, GKV10, was selected for a single-crystal X-ray diffraction analysis to unequivocally establish its molecular structure, conformation, and to understand the presence of different intermolecular interactions in its crystal lattice. A cooperative synergy of the C-H&middot;&middot;&middot;O, C-H&middot;&middot;&middot;N, C-H&middot;&middot;&middot;S, C-H&middot;&middot;&middot;&pi;, and &pi;&middot;&middot;&middot;&pi; intermolecular interactions was present in the crystal structure, which contributed towards the overall stabilization of the lattice. A molecular docking study was conducted for all the test compounds against Candida albicans lanosterol-14&alpha;-demethylase (pdb = 5 tzl). The binding stability of the highly promising antifungal test compound, GKV15, from the series was then evaluated by molecular dynamics studies