Modulation of the binding affinity of naproxen to bovine serum albumin by conversion of the drug into amino acid ester salts

Comprehensive evaluation of ibuprofenate amino acid isopropyl esters: insights into antioxidant activity, cytocompatibility, and cyclooxygenase inhibitory potential

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for pain relief and inflammation management, but there are challenges related to poor solubility and bioavailability. We explored modifications of ibuprofen (IBU) by forming ionic pairs using amino acid alkyl esters to enhance solubility without compromising the ability to inhibit cyclooxygenase (COX)-1 and COX-2). We comprehensively evaluated the pharmacological properties of the IBU derivatives, focusing on antioxidant activity (based on the ability to scavenge DPPH and ABTS), biocompatibility (using human dermal fibroblasts), and COX inhibitory potential. The antioxidant activity assays significantly enhanced DPPH scavenging activity for several IBU derivatives, particularly [L-SerOiPr][IBU], suggesting potential therapeutic benefits. There was enhanced cell viability with select derivatives, indicating possible stimulatory effects on cellular proliferation. Finally, predominant COX-1 inhibition across derivatives was consistent with IBU's profile. This study provides insights into the pharmacological properties of IBU amino acid derivatives, highlighting their potential as therapeutic agents. Further exploration into structure-activity relationships and in vivo efficacy warranted to advance these derivatives toward clinical applications, offering prospects for novel NSAIDs with enhanced efficacy and reduced side effects.

Characterization of naproxen salts with amino acid esters and their application in topical skin preparations

In the study, the modification of naproxen (NAP) with esters of four amino acids (AAs): glycine (GlyOiPr), L-proline (ProOiPr), L-leucine (LeuOiPr), and L-serine (SerOiPr) isopropyl ester was performed to improve water solubility and enhance the permeation of the drug through the skin in comparison to the parent NAP. The NAP derivatives were prepared using the equimolar ratio of the components. In-depth NMR and FTIR analysis revealed that the salts formed with the proton transfer from the carboxylic group of NAP to the amine group of the appropriate AA ester. The NAP salts exhibited improved solubility in water and PBS solution (pH 7.4) when compared to parent NAP. The values of the partition coefficient (log PO/W) for prepared salts were lower than for NAP, however, the salts maintained hydrophobic character determined by the positive values of log P. The In vitro permeation through the pig skin performed in Franz diffusion cells showed that all NAP salts exhibited a higher cumulative mass of permeated NAP (Q24h) than the parent acid. The highest permeation value was noted for [ProOiPr][NAP], with a pseudo-steady state flux (Jss) 32.5 µg NAP cm-2h-1, and Q24h = 246.4 µg NAP cm-2, it was 2.5 % of the applied dose. Moreover, topical preparations with [ProOiPr][NAP] and NAP were prepared based on two vehicles - Celugel® and Pentravan®- approved in pharmacy recipes. The permeation experiments through the Strat-M® showed, that both the Jss and Q24h of permeated drug from preparations containing [ProOiPr][NAP], were statistically several times greater than from the respective preparations with the unmodified acid. Additionally, preparations with [ProOiPr][NAP] provided significantly improved permeation of NAP than two commercial preparations, one of which contained naproxen as the acid and the other - as the sodium salt.

Design and characterization of BSA-mycophenolic acid nanocomplexes: Antiviral activity exploration

The interactions between bovine serum albumin (BSA) and mycophenolic acid (MPA) were investigated in silico through molecular docking and in vitro, using fluorescence spectroscopy. Dynamic light scattering and scanning electron microscopy were used to figure out the structure of MPA-Complex (MPA-C). The binding affinity between MPA and BSA was determined, yielding a Kd value of (12.0 ± 0.7) μM, and establishing a distance of 17 Å between the BSA and MPA molecules. The presence of MPA prompted protein aggregation, leading to the formation of MPA-C. The cytotoxicity of MPA-C and its ability to fight Junín virus (JUNV) were tested in A549 and Vero cell lines. It was found that treating infected cells with MPA-C decreased the JUNV yield and was more effective than free MPA in both cell line models for prolonged time treatments. Our results represent the first report of the antiviral activity of this type of BSA-MPA complex against JUNV, as assessed in cell culture model systems. MPA-C shows promise as a candidate for drug formulation against human pathogenic arenaviruses.

Glycation and drug binding by serum albumin

Accumulation of glycation products in patients with hyperglycaemic conditions can lead to their reaction with the proteins in the human system such as serum albumin, haemoglobin, insulin, plasma lipoproteins, lens proteins and collagen among others which have important biological functions. Therefore, it is important to understand if glycation of these proteins affects their normal action not only qualitatively, but also importantly quantitatively. Glycation of human serum albumin can easily be carried out over period of weeks and its drug transportability may be examined, in addition to characterisation of the amadori products. A combination of ultrasensitive isothermal titration calorimetry, differential scanning calorimetry, spectroscopy and chromatography provides structure-property-energetics correlations which are important to obtain mechanistic aspects of drug recognition, conformation of the protein, and role of amadori products under conditions of glycation. The role of advance glycation end products is important in recognition of antidiabetic drugs. Further, the extent of glycation of the protein and its implication on drug transportability investigated by direct calorimetric methods enables unravelling mechanistic insights into role of functionality on drug molecules in the binding process, and hinderance in the recognition process, if any, as a result of glycation. It is possible that the drug binding ability of the protein under glycation conditions may not be adversely affected, or may even lead to strengthened ability. Rigorous studies on such systems with diverse functionality on the drug molecules is required which is essential in deriving guidelines for improvements in the existing drugs or in the synthesis of new molecular entities directed towards addressing diabetic conditions.

Evaluation of Solubility, Physicochemical Properties, and Cytotoxicity of Naproxen-Based Ionic Liquids

To solve the problems associated with poorly water-soluble nonsteroidal anti-inflammatory drugs (NSAIDs), naproxen-based ionic liquids (ILs) containing naproxen as an active pharmaceutical ingredient (API) anion were prepared with benzalkonium (tetradecyldimethylbenzyl ammonium), choline, and 1-octyl-3-methylimidazole as the cation. The structures and thermal properties were analyzed. Through the conductivity method, the solubility at 25 and 37 °C and the critical micelle concentration (CMC) at 25 °C were determined in water and ethanol. The octanol-water partition coefficients (K _ow) at 25 °C were measured with the shake-flask method. The cytotoxicity was evaluated with the MTT method. The results showed that the conversion of naproxen into the API-ILs increased the API's solubility in water by more than 850 times compared with the original API, and the thermostability was satisfactory with a lower glass transition temperature (t _g). Moreover, the variation trends of solubility, hydrophilicity, and K _ow were consistent with the different structures of naproxen-based ILs, except for benzalkonium naproxen. The CMC (10^-5-10^-6 M) in water and ethanol demonstrated that the naproxen-based ILs were surface activite ILs. The IC₅₀ values exhibited the low cytotoxicity of the naproxen-based ILs, which was better than 100 μM. The results provide essential information and a research basis for future topical and transdermal administration and oral administration of naproxen-based ILs.

New amino acid propyl ester ibuprofenates from synthesis to use in drug delivery systems

This study aimed to evaluate the effect of introducing structural modification of ibuprofen in the form of an ion pair on the permeability of ibuprofen through the skin and the properties of the adhesive layer of the medical patch produced. The active substances tested were the salts of ibuprofen obtained by pairing the anion of ibuprofen with organic cations such as propyl esters of amino acids such as tyrosine, tryptophan, histidine, or phenylalanine. For comparison, the penetration of unmodified ibuprofen and commercially available patches was also tested. Acrylate copolymers based on isobornyl methacrylate as a biocomponent and a monomer increasing the T g ("hard") were used to produce the adhesive layer of transdermal patches. The obtained patches were characterized in terms of adhesive properties and tested for the permeability of the active ingredient and the permeability of the active ingredient through the skin. This study demonstrates the possibility of developing acrylic-based photoreactive transdermal patches that contain biocomponents that can deliver a therapeutically appropriate dose of ibuprofen.

Isopropyl Amino Acid Esters Ionic Liquids as Vehicles for Non-Steroidal Anti-Inflammatory Drugs in Potential Topical Drug Delivery Systems with Antimicrobial Activity

New derivatives of non-steroidal anti-inflammatory drugs were synthesized via conjugation with L-amino acid isopropyl esters. The characteristics of the physicochemical properties of the obtained pharmaceutically active ionic liquids were determined. It has been shown how the incorporation of various L-amino acid esters as an ion pair affects the properties of the parent drug. Moreover, the antimicrobial activity of the obtained compounds was evaluated. The proposed structural modifications of commonly used drugs indicate great potential for use in topical and transdermal preparations.

Salicylic Acid as Ionic Liquid Formulation May Have Enhanced Potency to Treat Some Chronic Skin Diseases

In recent years, numerous studies have shown that conversion of conventional drugs in ionic liquid (IL) formulation could be a successful strategy to improve their physicochemical properties or suggest a new route of administration. We report the synthesis and detailed characterization of eight salicylic acid-based ILs (SA-ILs) containing cation non-polar or aromatic amino acid esters. Using in vitro assays, we preliminary evaluated the therapeutic potency of the novel SA-ILs. We observed that conversion of the SA into ionic liquids led to a decrease in its cytotoxicity toward NIH/3T3 murine embryo fibroblasts and human HaCaT keratinocytes. It should be mentioned is that all amino acid alkyl ester salicylates [AAOR][SA] inhibit the production of the proinflammatory cytokine IL-6 in LPS-stimulated keratinocytes. Moreover, keratinocytes, pretreated with [PheOMe][SA] and [PheOPr][SA] seem to be protected from LPS-induced inflammation. Finally, the novel compounds exhibit a similar binding affinity to bovine serum albumin (BSA) as the parent SA, suggesting a similar pharmacokinetic profile. These preliminary results indicate that SA-ILs, especially those with [PheOMe], [PheOPr], and [ValOiPr] cation, have the potential to be further investigated as novel topical agents for chronic skin diseases such as psoriasis and acne vulgaris.

Novel Naproxen Salts with Increased Skin Permeability

The paper presents the synthesis, full identification, and characterization of new salts-L-proline alkyl ester naproxenates [ProOR][NAP], where R was a chain from ethyl to butyl (including isopropyl). All obtained compounds were characterized by Nuclear Magnetic Resonance (NMR), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffractometry (XRD), and in vitro dissolution studies. The specific rotation, phase transition temperatures (melting point), and thermal stability were also determined. In addition, their lipophilicity, permeability, and accumulation in pigskin were determined. Finally, toxicity against mouse L929 fibroblast cells was tested. The obtained naproxen derivatives showed improved solubility and higher absorption of drug molecules by biological membranes. Their lipophilicity was lower and increased with the increase in the alkyl chain of the ester. The derivative with isopropyl ester had the best permeability through pigskin. The use of L-proline isopropyl ester naproxenate increased the permeation of naproxen through the skin almost four-fold. It was also shown that the increase in permeability is not associated with additional risk: all compounds had a similar effect on cell viability as the parent naproxen.