Anhydride prodrug of ibuprofen and acrylic polymers

Butyl methyl imidazolium silica sulfate (BMIm)SS: A novel hybrid nano-catalyst for highly efficient synthesis of new 1,2-diol monoesters of ibuprofen as the novel prodrugs of ibuprofen having potent analgesic property

The fabrication, characterization of butyl methyl imidazolium silica sulfate [BMIm]SS as a novel nano hybrid catalyst and its application in synthesis of new ibuprofen (IBP) 1,2-diol mono esters were described. [BMIm]SS catalyzed the reaction of IBP with epoxides to afford the new IBP 1,2-diol mono esters in good to excellent yields. The products were tested in vivo for the analgesic properties on female mice using formalin test. The test results revealed that most compounds, in particular compounds 1h, 1k and 1o displayed potent analgesic activity compare to IBP as a reference drug. No mortality was observed due to the toxicity of the synthesized compounds. The docking analysis was conducted that confirmed the strong binding affinity of active compounds to active site of murine cyclooxygenase-2 (COX-2) enzyme compare to IBP. The in silico pharmacokinetic profile, drug likeness and toxicity predictions were carried out for all compounds which determined that 1h can be suggested as an appropriate future drug candidate.

Less Reactive Thiol Ligands: Key towards Highly Mucoadhesive Drug Delivery Systems

As less reactive s-protected thiomers can likely interpenetrate the mucus gel layer to a higher extent before getting immobilized via disulfide bond formation with mucins, it was the aim of this study to develop a novel type of s-protected thiomer based on the less reactive substructure cysteine-N-acetyl cysteine (Cys-NAC) in order to obtain improved mucoadhesive properties. For this purpose, two types of s-protected thiomers, polyacrylic acid-cysteine-mercaptonicotinic acid (PAA-Cys-MNA) and polyacrylic acid-cysteine-N-acetyl cysteine (PAA-Cys-NAC), were synthesized and characterized by Fourier-transform infrared spectroscopy (FT-IR) and the quantification of attached disulfide ligands. The viscosity of both products was measured in the presence of NAC and mucus. Both thiomers were also evaluated regarding swelling behavior, tensile studies and retention time on the porcine intestinal mucosa. The FT-IR spectra confirmed the successful attachment of Cys-MNA and Cys-NAC ligands to PAA. The number of attached sulfhydryl groups was in the range of 660–683 µmol/g. The viscosity of both s-protected thiomers increased due to the addition of increasing amounts of NAC. The viscosity of the mucus increased in the presence of 1% PAA-Cys-MNA and PAA-Cys-NAC 5.6- and 10.9-fold, respectively, in comparison to only 1% PAA. Both s-protected thiomers showed higher water uptake than unmodified PAA. The maximum detachment force (MDF) and the total work of adhesion (TWA) increased in the case of PAA-Cys-MNA up to 1.4- and 1.6-fold and up to 2.4- and 2.8-fold in the case of PAA-Cys-NAC. The retention of PAA, PAA-Cys-MNA, and PAA-Cys-NAC on porcine intestinal mucosa was 25%, 49%, and 76% within 3 h, respectively. The results of this study provide evidence that less reactive s-protected thiomers exhibit higher mucoadhesive properties than highly reactive s-protected thiomers.

Covalently-controlled drug delivery via therapeutic methacrylic tissue adhesives

Therapeutic methacrylic (TMA) monomers lend local, covalently-controlled release of therapeutics, tunable mechanical properties, and increased cytocompatibility to cyanoacrylate medical adhesives.

Development of Poly Unsaturated Fatty Acid Derivatives of Aspirin for Inhibition of Platelet Function

The inhibition of platelet aggregation is key to preventing conditions such as myocardial infarction and ischemic stroke. Aspirin is the most widely used drug to inhibit platelet aggregation. Aspirin absorption can be improved further to increase its permeability across biologic membranes via esterification or converting the carboxylic acid to an anhydride. There are several reports indicating that ω-3 and ω-6 fatty acids such as linoleic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) separately inhibit platelet aggregation. Herein, we synthesize anhydride conjugates of aspirin with linoleic acid, EPA, and DHA to form aspirin anhydrides that are expected to have higher permeability across cellular membranes. These aspirin-fatty acid anhydrides inhibited platelet aggregation in washed human platelets and platelet-rich plasma in a dose-dependent manner. In particular, the aspirin-DHA anhydride displayed similar effectiveness to aspirin. Platelet aggregation studies conducted in the presence of various platelet agonists indicated that the aspirin-lipid conjugates act through inhibition of the cyclooxygenase (COX)-thromboxane synthase (TXAS) pathway. Hence, we performed detailed biochemical studies using purified COX-1 as well as TXAS stabilized in nanoscale lipid bilayers of nanodiscs to confirm results from the platelet aggregation studies. We show that although all of the aspirin conjugates act through the COX-TXAS pathway by inhibiting COX-1, the parent fatty acids do not act via this pathway. Finally, we studied the hydrolysis of these compounds in buffer and human plasma, and we demonstrate that all of the aspirin-fatty acid conjugates hydrolyze to the parent molecules aspirin and fatty acid in a controlled manner.

Enzymatic Polymerization of an Ibuprofen-Containing Monomer and Subsequent Drug Release

Novel ibuprofen-containing monomers comprising naturally occurring and biocompatible compounds were synthesized and subsequently polymerized via enzymatic methods. Through the use of a malic acid sugar backbone, ibuprofen was attached as a pendant group, and then subsequently polymerized with a linear aliphatic diol (1,3-propanediol, 1,5-pentanediol, or 1,8-octanediol) as comonomer using lipase B from Candida antarctica, a greener alternative to traditional metal catalysts. Polymer structures were elucidated by nuclear magnetic resonance and infrared spectroscopies, and thermal properties and molecular weights were determined. All polymers exhibited sustained ibuprofen release, with the longer chain, more hydrophobic diols exhibiting the slowest release over the 30 d study. Polymers were deemed cytocompatible using mouse fibroblasts, when evaluated at relevant therapeutic concentrations. Additionally, ibuprofen retained its chemical integrity throughout the polymerization and in vitro hydrolytic degradation processes. This methodology of enzymatic polymerization of a drug presents a more environmentally friendly synthesis and a novel approach to bioactive polymer conjugates.

Biodegradable polyesters containing ibuprofen and naproxen as pendant groups

Controlled release of nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen could be beneficial for the treatment of inflammatory diseases while reducing the side effects resulting from their continuous use. Novel biodegradable polyesters solely comprised of biocompatible components (e.g., tartaric acid, 1,8-octanediol, and ibuprofen or naproxen as pendant groups) have been synthesized using tin(II) 2-ethylhexanoate as catalyst at 130 °C and subsequently characterized to determine their structures and physicochemical properties. The polymers release the free drug (ibuprofen or naproxen) in vitro in a controlled manner without burst release, unlike the release rates achieved when the drugs are encapsulated in other polymers. These new biomaterials are not cytotoxic toward mouse fibroblasts up to 0.10 mg/mL. The drugs retain their chemical structure following hydrolytic degradation of the polymer, suggesting that bioactivity is preserved.

Preparation of well-defined ibuprofen prodrug micelles by RAFT polymerization

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to treat acute pain, fever, and inflammation and are being explored in a new indication in cancer. Side effects associated with long-term use of NSAIDs such as gastrointestinal damage and elevated risk of stroke, however, can limit their use and exploration in new indications. Here we report a facile method to prepare well-defined amphiphilic diblock copolymer NSAID prodrugs by direct reversible addition-fragmentation transfer (RAFT) polymerization of the acrylamide derivative of ibuprofen (IBU), a widely used NSAID. The synthesis and self-assembling behavior of amphiphilic diblock copolymers (PEG-PIBU) having a hydrophilic poly(ethylene glycol) block and a hydrophobic IBU-bearing prodrug block were investigated. Release profiles of IBU from the micelles by hydrolysis were evaluated. Furthermore, the antiproliferative action of the IBU-containing micelles in human cervical carcinoma (HeLa) and murine melanoma (B16-F10) cells was assessed.