Design and development of an injectable in situ forming drug delivery system of methotrexate for the treatment of rheumatoid arthritis

Nanostructured lipid carrier-based smart gel: a delivery platform for intra-articular therapeutics

The promising potential of nano-structured lipid carrier (NLC) polymeric gel of CUR as an effective treatment for rheumatoid arthritis by intra-articular route of administration was investigated. NLC composed of cetylpalmitate, Labrafac PG & Captex 200, Tween 80 and Labrasol. The hot homogenization method employed by melt ultrasonication was used. The formulated NLC dispersions were characterized and were suitably dispersed into the matrix of pluronic F-127(PLF-127) and pluronic F-68 (PLF-68). A two-factor three-level full factorial design was employed to deduce the optimal concentrations of PLF-127 and PLF-68. The optimized formulations were sterilized by gamma radiation. The formulated NLC smart gels were characterized and evaluated for various parameters. The efficacy evaluation by antigen-induced monoarthritis model and biocompatibility testing by histopathological studies was performed. Formulated NLCs exhibited an average particle size of 165.12 nm, entrapment efficiency of 72.15%, and zeta potential of -21.67 mV. The optimized CUR-NLC smart gel was demonstrated to have a sol-gel transformation at 33.21 °C and 94.32% drug release at 84 h. NLC's which were sterile and easily syringeable, continued to remain within the colloidal range. CUR-NLC smart gels were found to be biocompatible and showed a significant reduction in rat knee joint inflammation compared to free drug.

Targeted drug delivery of Methotrexate in situ gels for the treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is considered a debilitating disease that increases the risk of significant morbidity and premature mortality. To circumvent drug-related toxicity and ineffectiveness of anti-inflammatory drugs, there is a significant need for an advanced delivery system that increases bioavailability. The feasibility of in situ gel of methotrexate sodium (MTS) as an effective management for Rheumatoid arthritis was investigated. It was formulated with pluronic F-127 (PLF-127) as primary polymer, hydroxypropyl methylcellulose K4M (HK4M), and polycarbophil (PCL) as a copolymer and characterized by various parameters. The efficacy evaluation by Freund's complete adjuvant (FCA) model, biocompatibility assessment by histopathological studies conducted. The optimized in situ gel (M4) was thermoresponsive, released 93.26 ± 2.39% MTS at 96 hours. In addition, distribution of MTS was even in the optimized sterile and syringeable in situ gel. In vivo studies on wistar rats demonstrated a substantial reduction in paw oedema during the 28-day study period and were biocompatible with the tissues at the injection site. The study was successful in formulating, optimizing MTS in situ gel for effective management of RA.

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.

Role of clove oil in solvent exchange-induced doxycycline hyclate-loaded Eudragit RS in situ forming gel

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Role of clove oil (CO) in doxycycline hyclate (DH)-loaded Eudragit RS (ERS) in situ forming gel (ISG) was investigated.

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CO could solubilize ERS and increase the viscosity of ISG and also minimize DH burst release with sustainable DH release.

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ISGs comprising CO could expel through the 27-gauge needle and transform into matrix depot in simulated crevicular fluid.

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Antimicrobial activities against all test bacterias were increased when increasing CO and N-methyl pyrrolidone (NMP) ratio.

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DH-loaded ERS ISG comprising CO could be used as a local drug delivery system for periodontitis treatment.

Solvent exchange induced in situ forming gel (ISG) is the promising drug delivery system for periodontitis treatment owing to the prospect of maintaining an effective high drug level in the gingival crevicular fluid. In the present study, the influence of clove oil (CO) on the characteristics of doxycycline hyclate (DH)-loaded ISG comprising Eudragit RS (ERS) was investigated including viscosity/rheology, syringeability, in vitro gel formation/drug release, matrix formation/solvent diffusion and antimicrobial activities. CO could dissolve ERS and increase the viscosity of ISG and its hydrophobicity could also retard the diffusion of solvent and hinder the drug diffusion; thus, the minimization of burst effect and sustained drug release were achieved effectively. All the prepared ISGs comprising CO could expel through the 27-gauge needle for administration by injection and transform into matrix depot after exposure to the simulated gingival crevicular fluid. The antimicrobial activities against Staphylococcus aureus, Escherichia coli, Streptococcus mutans and Porphyromonas gingivalis were increased when the ratio of CO and N-methyl pyrrolidone (NMP) was decreased from 1:1 to 1:10 owing to higher diffusion of DH except that for C. albicans was increased as CO amount was higher. Therefore, CO could minimize the burst while prolonging the drug release of DH-loaded ERS ISG for use as a local drug delivery system for periodontitis treatment.

Methotrexate: a gold standard for treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a painful, debilitating disease characterized by inflammation of the joints, with the proliferation of the synovium and the progressive erosion of cartilage and bone. The treatment of RA is still unsatisfactory, but a number of powerful disease-modifying antirheumatic drugs have become available, such as methotrexate (MTX). Even in the current era of biological targeted therapies, MTX remains the initial preferred antirheumatic drug and is considered to be the gold standard for treatment of RA. The combination of its perceived efficacy, acceptable safety profile, and low cost, as well as decades of clinical experience, makes MTX the cornerstone of treatment for RA and the anchor drug in combination with various biological agents. In this review, the authors aim to summarize the research done in the field of drug delivery systems of MTX according to its routes of administration for treatment of RA. The last part of the review addresses combination therapy with MTX and future direction in the drug delivery of MTX. This review also provides the reader with a general overview of RA and its therapeutic strategies with respect of MTX, which may bring uniformity in medical practice for effective management of RA.