Benefits of liposomal nonsteroid-anti-inflammatory drugs

Abstract

Introduction: Liposomes are small, spherical artificial vesicles that can be created from cholesterol and natural non-toxic phospholipids. Due to their size, hydrophobic and hydrophilic character (besides biocompatibility), liposomes are promising drug delivery systems. Topic: Liposomal formulations of non-steroidal anti-inflammatory drugs (NSAIDs) can be used in all population groups (children, adults, and the elderly) which gives them a wide range of applications. NSAIDs oral administration is associated with severe adverse effects in the gastrointestinal tract such as epigastric pain, heartburn, nausea, diarrhea, vomiting, peptic ulcer, and hepatic impairment. It has been observed in clinical trials, that liposomal formulations enhanced the drug permeability and the percentage of accumulated dose in the skin compared to control conventional gel formulations. Liposomal gel controls ibuprofen release and drug permeability in vitro and has shown a permeability pattern conducive to maintaining constant drug levels. Application: So far, liposomes containing sodium diclofenac, indomethacin, aceclofenac, and related NSAIDs have been produced in laboratory conditions. Liposomal technology is most commonly applied in cosmetology, cancer therapy and yet unexplored application possibilities for liposomes, such as therapy for Alzheimer's disease. Although varying in size and structure, they all possess certain common advantages - increased dermal availability of lipophilic drugs and their targeted delivery onto the required location. Liposomes have been proven highly effective in terms of retaining the NSAIDs in the synovial cavity, mostly because of their size and chemical composition. Undesirable therapy effects, fast clearance, and exposure to nontargeted sites could be minimized by administering NSAIDs using liposomes as carriers. Side effects and complications associated with the long-term oral and intramuscular applications of NSAIDs could especially be avoided using their liposomal formulations. Liposomes can be seen as ideal carriers for anti-inflammatory drugs as their ability to (passively) target sites of inflammation and release their content to inflammatory target cells enables them to increase local efficacy with only limited systemic exposure and adverse effects, improving bioavailability and patient compliance. A few NSAIDs are experimentally formulated in liposomes having improved pharmacokinetic characteristics. Further clinical investigations will show their pharmaco-dynamic effects. The in vitro release and ex vivo permeation (permeability) study showed a prolonged diclofenac release with high permeation flux. Conclusion: The use of liposomes as drug carriers becomes a notable positive step in the treatment of inflammatory, pain-causing, and rheumatic diseases. Liposomes present an attractive delivery system due to their flexible physicochemical and biophysical properties, which allow easy manipulation to address the different delivery considerations. The main objectives for the development of NSAIDs in liposomal carriers are deeper penetration of the active substance, fewer side effects, better and longer effect, the ability to change the characteristics of both the drug and the carrier, and adequate dose adjustment. Despite several challenges that accordingly still need to be addressed, liposomal drug formulations have significant health-promoting potential. Despite the encouragement of NSAID development and research studies, it still takes a long time for liposomal NSAID formulations to become available for everyday use.

Keywords

• liposomes
• nonsteroid-anti-inflammatory drugs