Tolmetin Sodium Fast Dissolving Tablets for Rheumatoid Arthritis Treatment: Preparation and Optimization Using Box-Behnken Design and Response Surface Methodology.

Tolmetin sodium (TLM) is a non-steroidal anti-inflammatory drug (NSAIDs). TLM is used to treat inflammation, skeletal muscle injuries, and discomfort associated with bone disorders. Because of the delayed absorption from the gastro intestinal tract (GIT), the currently available TLM dosage forms have a rather protracted start to the effect, according to pharmacokinetic studies. The aim of this study was to create a combination for TLM fast dissolving tablets (TLM-FDT) that would boost the drug's bioavailability by increasing pre-gastric absorption. The TLM-FDTs were developed using a Box-Behnken experimental design with varied doses of crospovidone (CP), croscarmellose sodium (CCS) as super-disintegrants, and camphor as a sublimating agent. In addition, the current study used response surface approach to explore the influence of various formulation and process factors on tablet qualities in order to verify an optimized TLM-FDTs formulation. The optimized TLM-FDTs formula was subsequently evaluated for its in vivo anti-inflammatory activity. TLM-FDTs have good friability, disintegration time, drug release, and wetting time, as well as fast disintegration and dissolution behavior. Significant increase in drug bioavailability and reliable anti-inflammatory efficacy were also observed, as evidenced by considerable reductions in paw thickness in rats following carrageenan-induced rat paw edema. For optimizing and analyzing the effect of super-disintegrants and sublimating agents in the TLM-FDTs formula, the three-factor, three-level full factorial design is a suitable tool. TLM-FDTs are a possible drug delivery system for enhancing TLM bioavailability and could be used to treat rheumatoid arthritis.

Crystal structure of the non-steroidal anti-inflammatory drug (NSAID) tolmetin sodium.

The asymmetric unit of the title compound, sodium 2-[1-methyl-5-(4-methyl-benzo-yl)-1H-pyrrol-2-yl]acetate dihydrate, Na+·C15H14NO3 -·2H2O, contains two sodium cations, two organic anions (A and B) and two water mol-ecules. The coordination geometry around the sodium cations corresponds to a distorted octa-hedron. Each pair of sodium cations (A-A or B-B) is chelated by two bridging anions coordinated by the O atoms of the deprotonated carb-oxy-lic groups, and each sodium atom is coordinated by an O atom of a third anion, which connects pairs of sodium atoms, and a water mol-ecule. As a result, a two-dimensional polymer is formed in the crystal. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to analyze the inter-molecular contacts present in the crystal.

Controlled release alginate-chitosan microspheres of tolmetin sodium prepared by internal gelation technique and characterized by response surface modeling

Tolmetin sodium (TS) is a powerful non-steroidal mitigating drug for the treatment of rheumatoid joint inflammation, osteoarthritis, and adolescent rheumatoid joint pain. In addition to its gastrointestinal (GIT) problems, TS has a short biological half-life (1 hr). In a trial to overcome these side effects and control the rate of (TS) release, chitosan coated alginate microspheres are recommended. A Box-Behnken experimental design was employed to produce controlled release microspheres of TS in the sodium alginate and chitosan copolymers (Alg-Ch) by emulsification internal gelation methodology. The effect of critical formulation variables namely, drug to polymer ratio (D:P ratio), speed of rotation and span 80% on drug encapsulation efficiency (% EE), drug release at the end of 2 hours (Rel2) and drug release at the end of 8 hours (Rel8) were analyzed using response surface modeling. The parameters were assessed using the F test and mathematical models containing only the significant terms were generated for each parameter using multiple linear regression analysis. The produced microspheres were spherical in shape with extensive pores at D:P ratio 1:1 and small pores at a drug to polymer ratio (D:P ratio) 1:3. Differential scanning calorimetry (DSC) affirmed the steady character of TS in microspheres and revealed their crystalline form. All formulation variables examined exerted a significant influence on the drug release, whereas the speed emerged as a lone factor significantly influencing % EE. Increasing the D: P ratio decreases the release of the drug after two and 8 hours. The increase in speed results in an increase in drug release after two and eight hours. The drug release from the microspheres followed zero order kinetics. TS Alg-Ch microspheres exhibited a significant anti-inflammatory effect on incited rat paw edema after eight hours. These results revealed that the internal gelation technique is a promising method to control TS release and eradicate GIT side effects using Alg-Ch copolymers.

Tolmetin sodium-loaded thermosensitive mucoadhesive liquid suppositories for rectal delivery; strategy to overcome oral delivery drawbacks.

Tolmetin sodium (TS) is a nonsteroidal anti-inflammatory drug (NSAID) indicated for treatment of musculoskeletal issues. As other NSAID, TS displays a marked side effects on the gastro-intestinal (GI) tract after oral administration. Traditional solid suppositories can cause pain and discomfort for patients, may reach the end of the colon; consequently, the drug can undergo the first-pass effect. TS liquid suppository (TS-LS) was developed to enhance patient compliance and rectal mucosal safety in high-risk patients receiving highly NSAID therapy. This work was conducted to optimize and evaluate Poloxamer P407/P188-based thermoresponsive TS-LS by using mucoadhesive polymers such as methylcellulose (MC). TS-LS was prepared by cold method and characterized their in vitro physicochemical properties as gelation temperature (GT), gel strength, bioadhesive properties, and in vitro release. The safety of the prepared suppository on rectum, stomach, and liver was evaluated histologically. Pharmacokinetic analyses were performed to compare rectal TS-LS to orally Rhumtol® capsules. The results showed that the optimized TS-LS; composed of P407/P188/MC (21/9/0.5% w/w) displayed gelation at rectum temperature ∼32.90 °C, gel strength of 21.35 s and rectal retention force at the administration site of 24.25 × 102 dyne/cm2. Moreover, TS-LS did not cause any morphological damage to the rectal tissues. Pharmacokinetic parameters of optimized TS-LS formulation revealed 4.6 fold increase in bioavailability as compared to Rhumtol® capsules. Taken together, the results demonstrated that liquid suppository is a potential and physically safe rectal delivery carrier for improvement rectal bioavailability and in vivo safety of TS.

Effect of formulation and processing variables on the characteristics of tolmetin microspheres prepared by double emulsion solvent diffusion method.

The aim of this study was to evaluate microencapsulated controlled release preparations of tolmetin sodium using ethylcellulose as a retardant material. Microspheres were prepared by using water-in-oil-in-oil (W/O(1)/O(2)) double-emulsion solvent diffusion method, using different ratios of ethylcellulose to tolmetin sodium. Span 80 was used as the droplet stabilizer and n-hexane was added to harden the microspheres. The prepared microspheres were characterized for their micromeritic properties, drug content, loading efficiency, production yield, and particle size. Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray powder diffractometry and scanning electron microscopy were used to characterize microparticles. The in vitro release studies were performed in pH 1.2 and 7.4. The prepared microspheres were spherical in shape. The drug-loaded microspheres showed near to the theoretical of entrapment and release was extended up to 24. The X-ray diffractogram and differential scanning thermographs showed amorphous state of the drug in the microspheres. It was shown that the drug: polymer ratio, stirring rate, volume of dispersing medium and surfactant influenced the drug loading, particle size and drug release behavior of the formed microparticles. The results showed that, generally, an increase in the ratio of drug: polymer (0.5:1) resulted in a reduction in the release rate of the drug which may be attributed to the hydrophobic nature of the polymer. The in vitro release profile could be modified by changing various processing and formulation parameters to give a controlled release of drug from the microparticules. The release of tolmetin was influenced by the drug to polymer ratio and particle size and was found to be diffusion and erosion controlled. The best-fit release kinetic was achieved with Peppas model.