Loxoprofen

Loxoprofen is a non-steroidal anti-inflammatory drug.

Preparation and Optimization of Immediate Release/Sustained Release Bilayered Tablets of Loxoprofen Using Box-Behnken Design.[Pubmed:27401334]

AAPS PharmSciTech. 2017 May;18(4):1125-1134.

The aim of our current study was to characterize and optimize Loxoprofen immediate release (IR)/sustained release (SR) tablet utilizing a three-factor, three-level Box-Behnken design (BBD) combined with a desirability function. The independent factors included ratio of drug in the IR layer to total drug (X 1), ratio of HPMC to drug in the SR layer (X 2), and ratio of Eudragit RL PO to drug in the SR layer (X 3). The dependent variables assessed were % drug released in distilled water at 30 min (Y 1), % drug released in pH 1.2 at 2 h (Y 2), and % drug released in pH 6.8 at 12 h (Y 3). The responses were fitted to suitable models and statistical validation was performed using analysis of variance. In addition, response surface graphs and contour plots were constructed to determine the effects of different factor level combinations on the responses. The optimized Loxoprofen IR/SR tablets were successfully prepared with the determined amounts of ingredients that showed close agreement in the predicted and experimental values of tablet characterization and drug dissolution profile. Therefore, BBD can be utilized for successful optimization of Loxoprofen IR/SR tablet, which can be regarded as a suitable substitute for the current marketed formulations.

Characterization of loxoprofen transport in Caco-2 cells: the involvement of a proton-dependent transport system in the intestinal transport of loxoprofen.[Pubmed:27514365]

Biopharm Drug Dispos. 2016 Nov;37(8):447-455.

Loxoprofen, a propionate non-steroidal anti-inflammatory drug (NSAID), is used widely in East Asian countries. However, little is known about the transport mechanisms contributing to its intestinal absorption. The objectives of this study were to characterize the intestinal transport of Loxoprofen using the human intestinal Caco-2 cell model. The transport of Loxoprofen was investigated in cellular uptake studies. The uptake of Loxoprofen into Caco-2 cells was pH- and concentration-dependent, and was described by a Michaelis-Menten equation with passive diffusion (Km : 4.8 mm, Vmax : 142 nmol/mg protein/30 s, and Kd : 2.2 mul/mg protein/30 s). Moreover, the uptake of Loxoprofen was inhibited by a typical monocarboxylate transporter (MCT) inhibitor as well as by various monocarboxylates. The uptake of [(14) C] l-lactic acid, a typical MCT substrate, in Caco-2 cells was saturable with relatively high affinity for MCT. Because Loxoprofen inhibited the uptake of [(14) C] l-lactic acid in a noncompetitive manner, it was unlikely that Loxoprofen uptake was mediated by high-affinity MCT(s). Our results suggest that transport of Loxoprofen in Caco-2 cells is, at least in part, mediated by a proton-dependent transport system. Copyright (c) 2016 John Wiley & Sons, Ltd.

Loxoprofen: A Review in Pain and Inflammation.[Pubmed:27444038]

Clin Drug Investig. 2016 Sep;36(9):771-781.

Loxoprofen (Loxonin((R)), Loxonin((R)) Pap, Loxonin((R)) Tape) is a prodrug-type NSAID that is available in several formulations, including 60 mg tablets, 100 mg hydrogel patches and 50 or 100 mg tape. In active comparator-controlled trials, oral Loxoprofen therapy (ranging from 2 days to 6 weeks' duration depending on the pain type) provided analgesic efficacy that generally did not significantly differ from that of celecoxib for postoperative pain or frozen shoulder, ibuprofen for knee osteoarthritis or naproxen for lumbar pain. In double-blind, double-dummy, multicentre trials, Loxoprofen hydrogel patches were noninferior to oral Loxoprofen with regard to rates of final overall symptomatic improvement over 1-4 weeks in patients with knee osteoarthritis, myalgia or trauma-induced swelling and pain. Loxoprofen hydrogel patches were also noninferior to other commercially available patches (ketoprofen and indometacin) over 2 or 4 weeks in patients with knee osteoarthritis or myalgia in open-label studies. Oral and topical Loxoprofen were generally well tolerated in clinical trials. Thus, Loxoprofen is a useful analgesic option for patients with pain and inflammation, with topical Loxoprofen potentially reducing the risk of gastrointestinal, cardiovascular and renal complications associated with oral NSAID use.

Identification and Structure Elucidation of Forced Degradation Products of the Novel Propionic acid Derivative Loxoprofen: Development of Stability-Indicating Chromatographic Methods Validated as per ICH Guidelines.[Pubmed:27988488]

J Chromatogr Sci. 2017 Apr 1;55(4):417-428.

Loxoprofen sodium (LOX) is a recently developed novel propionic acid derivative. Owing to its instability under both hydrolytic and oxidative conditions, the development of simple, rapid and sensitive methods for its determination in the presence of its possible forced degradation products becomes essential. Two simple chromatographic methods, high-performance thin layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC), were developed associated with ultraviolet (UV) detection. In HPTLC-densitometric method, the separation of LOX from its degradation products was achieved using silica gel F254 plates and toluene:acetone:acetic acid (1.8:1.0:0.1, v/v/v) as the developing system followed by densitometric scanning at 220 nm. In the HPLC-UV method, the separation was performed using isocratic elution system with acetonitrile: 0.15% triethylamine (pH 2.2) (50:50, v/v) on C18 analytical column. The flow rate was optimized at 1.0 mL.min-1 and UV detection was achieved at 220 nm. Validation was performed in accordance with the International Conference on Harmonization guidelines and the method was perfectly applied for determination of LOX in its pharmaceutical preparation. The results obtained were statistically compared to those obtained after application of the official HPLC method, where no significant difference was found incompliance with precision and accuracy. Identification and characterization of the possible hydrolytic degradation product under alkaline conditions and that produced during oxidative degradation using hydrogen peroxide were structurally elucidated using infrared and mass spectrometry analyses.