New Dosage Formulations for Targeted Delivery of Cyclo-Oxygenase-2 Inhibitors

COX 2-inhibitors; a thorough and updated survey into combinational therapies in cancers

Cyclooxygenase (COX) enzymes are pivotal in inflammation and cancer development. COX-2, in particular, has been implicated in tumor growth, angiogenesis, and immune evasion. Recently, COX-2 inhibitors have arisen as potential therapeutic agents in cancer treatment. In addition, combining COX inhibitors with other treatment modalities has demonstrated the potential to improve therapeutic efficacy. This review aims to investigate the effects of COX inhibition, both alone and in combination with other methods, on signaling pathways and carcinogenesis in various cancers. In this study, a literature search of all major academic databases was conducted (PubMed, Scholar google), including the leading research on the mechanisms of COX-2, COX-2 inhibitors, monotherapy with COX-2 inhibitors, and combining COX-2-inhibitors with chemotherapeutic agents in tumors. The study encompasses preclinical and clinical evidence, highlighting the positive findings and the potential implications for clinical practice. According to preclinical studies, multiple signaling pathways implicated in tumor cell proliferation, survival, invasion, and metastasis can be suppressed by inhibiting COX. In addition, combining COX inhibitors with chemotherapy drugs, targeted therapies, immunotherapies, and miRNA-based approaches has enhanced anti-tumor activity. These results suggest that combination therapy has the potential to overcome resistance mechanisms and improve treatment outcomes. However, caution must be exercised when selecting and administering combination regimens. Not all combinations of COX-2 inhibitors with other drugs result in synergistic effects; some may even have unfavorable interactions. Therefore, personalized approaches that consider the specific characteristics of the cancer and the medications involved are crucial for optimizing therapeutic strategies. In conclusion, as monotherapy or combined with other methods, COX inhibition bears promise in modulating signaling pathways and inhibiting carcinogenesis in various cancers. Additional studies and well-designed clinical trials are required to completely elucidate the efficacy of COX inhibition and combination therapy in enhancing cancer treatment outcomes. This narrative review study provides a detailed summary of COX-2 monotherapy and combination targeted therapy in cancer treatment.

Development and characterization of trans-anethole-containing solid lipid microparticles: antiinflammatory and gastroprotective effects in experimental inflammation

The present study prepared, optimized, and characterized solid lipid microparticles that contained trans-anethole (SLMAN), evaluated their antiinflammatory activity in acute and chronic inflammation models, and investigated their effects on the gastric mucosa in arthritic rats. The microparticles were obtained by a hot homogenization process and characterized by physicochemical analyses. The acute inflammatory response was induced by an intradermal injection of 0.1 ml of carrageenan solution (200 μg) in the hind paw. The rats were treated orally with a single dose of SLMAN 1 h before induction of the inflammatory response. The chronic inflammatory response was induced by the subcutaneous application of 0.1 ml of complete Freund's adjuvant suspension (500 µg) in the hind paw. SLMAN was orally administered, starting on the day of arthritis induction, and continued for 21 days. The results showed that SLMAN was obtained with good encapsulation efficiency. Treatment with SLMAN at doses of 25 and 50 mg/kg was as effective as trans-anethole (AN) at a dose of 250 mg/kg on acute and chronic inflammatory responses. Histological analyses showed that treatment with SLMAN did not aggravate lesions in the gastric mucosa in arthritic rats. These results indicated that treatment with SLMAN at a dose that was 5-10 times lower than non-encapsulated AN exerted an inhibitory effect on acute and chronic inflammatory responses, suggesting the better bioavailability and efficacy of microencapsulated AN without aggravating lesions in the gastric mucosa in arthritic rats.

Polymer colloids as drug delivery systems for the treatment of arthritis

The most common types of arthritis are osteoarthritis (OA) and rheumatoid arthritis (RA) which are themain causes of disability and pain among older people. Current treatment of arthritis mainly consists of oral and intra-articular medications. Despite the efficacy of the intraarticular injections over the oral treatment, it is still limited by the rapid clearance of the injected drug. Therefore, a rational design of drug delivery systems (DDSs) able to delivery drugs in controlled manner and for required period of time to the arthritis joint is a key in developing safe and effective formulations for OA and RA. In this paper various colloidal systems like nanoparticles, liposomes, cationic carriers, hydrogels, and emulsion-based carriers were presented and discussed in light of their use and efficacy as delivery systems to transport therapeutics for arthritis treatment. Factors influencing the delivery efficacy such as size, charge, structure, drug uptake, retention and its release profile alongside with cytocompatibility and safety were addressed. Moreover, the advantages and disadvantages of the different colloidal systems were emphasised.

Selective COX-2 inhibitors as anticancer agents: a patent review (2014-2018)

INTRODUCTION

COX-2 is a key enzyme in the process of prostaglandins (PGs) synthesis. The products of this enzyme could play a major role as the mediators of the inflammatory response and some other medical states such as cancer. The design and synthesis of novel selective COX-2 inhibitors have always been attractive to researchers. This review discusses the structures of novel COX-2 inhibitors synthesized during the last five years and describes their efficacy as anticancer agents.

AREAS COVERED

It is well established that COX-2 is overexpressed in many different cancers and treatment with selective COX-2 inhibitors could relieve their symptoms and limit their adverse sequences.

EXPERT OPINION

The diversity of selective COX-2 inhibitors is mainly related to the types of scaffolds. Monocyclic, bicyclic, tricyclic, and acyclic scaffolds with different pharmacological effects and toxicological profiles could be found in the family of selective COX-2 inhibitors. The great interest of the researchers in this field is due to the importance of selective COX-2 inhibitors as a relatively safe and effective set of compounds which could present different properties such as antirheumatic, anti-inflammatory, antiplatelet, anti-Alzheimer's disease, anti-Parkinson's disease, and anticancer.

Can active components of licorice, glycyrrhizin and glycyrrhetinic acid, lick rheumatoid arthritis?

OBJECTIVES

This review stated the possible application of the active components of licorice, glycyrrhizin (GL) and glycyrrhetinic acid (GA), in rheumatoid arthritis (RA) treatment based on the cyclooxygenase (COX)-2/thromboxane A2 (TxA2) pathway.

METHODS

The extensive literature from inception to July 2015 was searched in PubMed central, and relevant reports were identified according to the purpose of this study.

RESULTS

The active components of licorice GL and GA exert the potential anti-inflammatory effects through, at least in part, suppressing COX-2 and its downstream product TxA2. Additionally, the COX-2/TxA2 pathway, an auto-regulatory feedback loop, has been recently found to be a crucial mechanism underlying the pathogenesis of RA. However, TxA2 is neither the pharmacological target of non-steroidal anti-inflammatory drugs (NSAIDs) nor the target of disease modifying anti-rheumatic drugs (DMARDs), and the limitations and side effects of those drugs may be, at least in part, attributable to lack of the effects on the COX-2/TxA2 pathway. Therefore, GL and GA capable of targeting this pathway hold the potential as a novel add-on therapy in therapeutic strategy, which is supported by several bench experiments.

CONCLUSIONS

The active components of licorice, GL and GA, could not only potentiate the therapeutic effects but also decrease the adverse effects of NSAIDs or DMARDs through suppressing the COX-2/TxA2 pathway during treatment course of RA.

Novel thermosensitive in situ gel based on poloxamer for uterus delivery

Side effects and drug residues are major concerns affecting hormone therapy of bovine reproductive diseases. Fertility-promoting intrauterine infusion liquid (FPL), an effective alternative to hormone therapy, is associated with short retention time and low therapeutic efficacy. To address these problems, we developed a thermosensitive in situ gel based on poloxamer 407 for local uterine administration. To achieve the desired gelling temperature and enhance local retention property, we added poloxamer 188 and HPMC to the formulation containing poloxamer 407 and FPL. After screening was performed, the optimized formulation showed good temperature sensitivity in vitro and in vivo. Gelation temperature was approximately 27°C. In vitro release tests showed that icariin (the major active compound in FPL) was slow released from in situ forming gel. After the gel was locally administered, uterine and ovarian indexes were significantly increased in the gel group compared with the control group (P<0.05). The serum estradiol level of the gel group was significantly higher than that of the control group (P<0.01). Histological evaluation did not show mucosa irritation in the gel group. Therefore, the proposed in situ forming gel system based on poloxamer 407 is a promising local drug delivery system to treat bovine uterine diseases.

Study of pharmacokinetics of an in situ forming gel system for controlled delivery of florfenicol in pigs

To reduce florfenicol (FFC) administration frequency in veterinary use, the drug was currently developed into in situ forming gel. Twelve pigs were randomly divided into two groups (six pigs per group). A single i.m. dose of 40 mg/kg body weight (b.w.) was given to pigs, group one was given FFC in situ forming gel, and group two was given FFC conventional injection. High-performance liquid chromatography (HPLC) was used to determine FFC plasma concentrations. There were significant differences (P < 0.01) between FFC in situ forming gel and conventional injection, in pharmacokinetic parameters MRT (mean retention time) (57.79 ± 2.88) h versus (15.94 ± 1.29) h, AUC (area under the concentration-time curve) (421.54 ± 8.97) μg·h/mL versus (168.16 ± 4.59) μg·h/mL, tmax (time of occurrence of cmax ) (9.00 ± 2.68) h versus (4.33 ± 0.82) h, cmax (maximum plasma concentration) (6.87 ± 0.66) μg/mL versus (12.01 ± 0.66) μg/mL, t1/2λz (terminal elimination half-life) (38.04 ± 2.20) h versus (9.15 ± 2.71) h. The results demonstrated that the in situ forming gel system could shorten dosing interval of FFC and thus achieved less frequent administration during long-term treatment.

The use of lipid-based nanocarriers for targeted pain therapies

Sustained delivery of analgesic agents at target sites remains a critical issue for effective pain management. The use of nanocarriers has been reported to facilitate effective delivery of these agents to target sites while minimizing systemic toxicity. These include the use of biodegradable liposomal or polymeric carriers. Of these, liposomes present as an attractive delivery system due to their flexible physicochemical properties which allow easy manipulation in order to address different delivery considerations. Their favorable toxicity profiles and ease of large scale production also make their clinical use feasible. In this review, we will discuss the concept of using liposomes as a drug delivery carrier, their in vitro characteristics as well as in vivo behavior. Current advances in the targeted liposomal delivery of analgesic agents and their impacts on the field of pain management will be presented.

Complexities in the pharmacologic management of osteoarthritis pain

OBJECTIVE

To discuss challenges in the pharmacologic management of osteoarthritis (OA) pain.

SCOPE

Literature searches through MEDLINE and Cochrane databases were used to identify relevant journal articles. The search was limited to articles published from January 1982 to January 2013. Additional references were obtained from articles extracted during the database search.

FINDINGS

Pharmacologic management of OA is aimed at alleviating pain and reducing functional impairment. Limitations of the most commonly prescribed agents (non-steroidal anti-inflammatory drugs [NSAIDs], acetaminophen, and opioids) and conflicting practice guidelines have led to physician and patient dissatisfaction. OA management guidelines advocate the use of acetaminophen, NSAIDs, serotonin-norepinephrine reuptake inhibitors (SNRIs) and opioids; however, these agents are associated with serious adverse events (AEs) and, in some cases, efficacy concerns. Acetaminophen, particularly at higher dosages, may lead to acute liver failure and gastrointestinal (GI) bleeding. NSAIDs present a significant GI bleeding risk and are also associated with a variety of renal complications, myocardial infarction and other serious cardiovascular complications. SNRIs can cause AEs such as hepatotoxicity and drug/drug interactions that can lead to serotonin syndrome. Opioids exhibit abuse potential and tramadol may demonstrate limited efficacy.

CONCLUSIONS

The safety and efficacy concerns associated with currently available OA treatment options establish a need to develop new treatment strategies. Disease-modifying agents and novel drug formulations are currently under investigation. As these new pharmacologic options evolve, their adoption may lower risk and improve clinical outcomes.

Celecoxib radiosensitizes the human cervical cancer HeLa cell line via a mechanism dependent on reduced cyclo-oxygenase-2 and vascular endothelial growth factor C expression

OBJECTIVE

The effects of celecoxib, a selective cyclo-oxygenase-2 (COX-2) inhibitor, on HeLa cervical cancer cell growth and radiosensitivity were investigated.

METHODS

Cytotoxicity was quantified using a 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyltetrazolium assay and effects on radiosensitivity were assessed using the lethal dose, quasithreshold dose, fraction surviving after 2 Gy irradiation and the radiosensitization ratio (SER, based on average lethal dose) determined using a single-hit multitarget model.

RESULTS

Celecoxib inhibited HeLa cell proliferation in a concentration- and time-dependent manner, with a half-maximal inhibitory concentration at 72 h of 44 μmol/l. Treatment with 20 μmol/l celecoxib for 72 h before irradiation was associated with an SER of 2.01. The SER of irradiated cells was 2.41 when treated with 40 μmol/l celecoxib before irradiation, 1.89 when treated simultaneously and 1.44 when treated after irradiation. Celecoxib downregulated COX-2 and vascular endothelial growth factor C (VEGF-C) expression evaluated immunohistochemically.

CONCLUSION

Celecoxib pretreatment radiosensitizes HeLa cells via a mechanism dependent on down-regulation of COX-2 and VEGF-C.

Micro- and Nano-Carrier Mediated Intra-Articular Drug Delivery Systems for the Treatment of Osteoarthritis

The objective of this paper is to provide readers with current developments of intra-articular drug delivery systems. In recent years, although the search for a clinically successful ideal carrier is ongoing, sustained-release systems, such as polymeric micro- and nanoparticles, liposomes, and hydrogels, are being extensively studied for intra-articular drug delivery purposes. The advantages associated with long-acting preparations include a longer effect of the drug in the action site and a reduced risk of infection due to numerous injections consequently. This paper discusses the recent developments in the field of intra-articular sustained-release delivery systems for the treatment of osteoarthritis.

Evaluation of the pro-inflammatory potential of nanostructured drug carriers in knee-joints of rats: effect on nociception, edema, and cell migration

Nanocarriers have been developed aiming at drug delivery; however, the irritating effects of these nanoparticles on naïve or inflamed articular tissues are not known. Poly(D,L-lactide) (N-PLA), methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (N-PEG-PLA), and Dynasan 116 (SLN) were used to prepare the nanocarriers. The average diameter (nm) and zeta potential (mV) of these particles were, respectively, 251 and -33.2, 169 and -22.1, and 105 and -13.0. Naive or carrageenan-primed knee-joints received 100 microL of nanoparticle suspensions or control solution. Incapacitation and articular diameter were determined hourly. Synovial leukocytes were counted 6 h after nanoparticle injection. N-PLA increased the articular diameter and leukocytes, but did not cause incapacitation. In primed knee-joints, N-PLA caused incapacitation, and increased the articular diameter and leukocytes. SLN did not produce inflammatory signals either in naive or primed knees. In primed knee-joints, N-PEG-PLA presented an intermediate effect characterized by an increase in the articular diameter, and a slight increase of leukocytes, but not incapacitation. These results suggest that solid lipid nanoparticles may be safer than polymeric ones, which may be correlated to their chemical composition and superficial charge.

Effects of indomethacin-loaded nanocapsules in experimental models of inflammation in rats

BACKGROUND AND PURPOSE

The effects of systemic treatment with indomethacin-loaded nanocapsules (IndOH-NC) were compared with those of free indomethacin (IndOH) in rat models of acute and chronic oedema.

EXPERIMENTAL APPROACH

The following models of inflammation were employed: carrageenan-induced acute oedema (measured between 30 min and 4 h), sub-chronic oedema induced by complete Freund's adjuvant (CFA) (determined between 2 h and 72 h), and CFA-induced arthritis (oedema measured between 14 and 21 days).

KEY RESULTS

IndOH or IndOH-NC produced equal inhibition of carrageenan-elicited oedema. However, IndOH-NC was more effective in both the sub-chronic (33 +/- 4% inhibition) and the arthritis (35 +/- 2% inhibition) model of oedema evoked by CFA, when compared with IndOH (21 +/- 2% and 14 +/- 3% inhibition respectively) (P < 0.01). In the CFA arthritis model, treatment with IndOH-NC markedly inhibited the serum levels of the pro-inflammatory cytokines tumour necrosis factor alpha and IL-6 (by 83 +/- 8% and 84 +/- 11% respectively), while the levels of the anti-inflammatory cytokine IL-10 were significantly increased (196 +/- 55%). The indices of gastrointestinal damage in IndOH-NC-treated animals were significantly less that those after IndOH treatment (58 +/- 16%, 72 +/- 6% and 69 +/- 2%, for duodenum, jejunum and ileum respectively).

CONCLUSIONS AND IMPLICATIONS

IndOH-NC produced an increased anti-inflammatory efficacy in long-term models of inflammation, allied to an improved gastrointestinal safety. This formulation might represent a promising alternative for treating chronic inflammatory diseases, with reduced undesirable effects.