Bioerodable Ketamine-Loaded Microparticles Fabricated Using Dissolvable Hydrogel Template Technology

Journey to the Market: The Evolution of Biodegradable Drug Delivery Systems

Biodegradable polymers have been used as carriers in drug delivery systems for more than four decades. Early work used crude natural materials for particle fabrication, whereas more recent work has utilized synthetic polymers. Applications include the macroscale, the microscale, and the nanoscale. Since pioneering work in the 1960’s, an array of products that use biodegradable polymers to encapsulate the desired drug payload have been approved for human use by international regulatory agencies. The commercial success of these products has led to further research in the field aimed at bringing forward new formulation types for improved delivery of various small molecule and biologic drugs. Here, we review recent advances in the development of these materials and we provide insight on their drug delivery application. We also address payload encapsulation and drug release mechanisms from biodegradable formulations and their application in approved therapeutic products.

Sustained-release ketamine-loaded lipid-particulate system: in vivo assessment in mice

Ketamine is used as an analgesic adjuvant in patients with chronic cancer-related pain. However, ketamine's short half-life requires frequent dose administration. Our aim was to develop a sustained release formulation of ketamine with high loading and to evaluate the in vivo pharmacokinetics and biodistribution in mice. Here, ketamine hydrochloride sustained-release lipid particles (KSL) were developed using the thin-film hydration method. The mean (± SD) encapsulation efficiency (EE) and drug loading (DL) of KSL were 65.6 (± 1.7)% and 72.4 (± 0.5)% respectively, and the mean (± SD) size of the lipid particles and the polydispersity index were 738 (± 137) nm and 0.44 (± 0.02) respectively. The release period of KSL in pH 7.4 medium was 100% complete within 8 h in vitro but a sustained-release profile was observed for more than 5 days after intravenous injection in mice. Importantly, the KSL formulation resulted in a 27-fold increase in terminal half-life, a threefold increase in systemic exposure (AUC_0-∞), and a threefold decrease in clearance compared with the corresponding pharmacokinetics for intravenous ketamine itself. Our findings demonstrate high encapsulation efficiency of ketamine in the sustained-release KSL formulation with prolonged release in mice after systemic dose administration despite 100% in vitro release within 8 h that requires future investigation.

A Recent Update on Drug Delivery Systems for Pain Management

Pain remains a global health challenge affecting approximately 1.5 billion people worldwide. Pain has been an implicit variable in the equation of human life for many centuries considering different types and the magnitude of pain. Therefore, developing an efficacious drug delivery system for pain management remains an open challenge for researchers in the field of medicine. Lack of therapeutic efficacy still persists, despite high throughput studies in the field of pain management. Research scientists have been exploiting different alternatives to curb the adverse side effects of pain medications or attempting a more substantial approach to minimize the prevalence of pain. Various drug delivery systems have been developed such as nanoparticles, microparticles to curb adverse side effects of pain medications or minimize the prevalence of pain. This literature review firstly provides a brief introduction of pain as a sensation and its pharmacological interventions. Second, it highlights the most recent studies in the pharmaceutical field for pain management and serves as a strong base for future developments. Herein, we have classified drug delivery systems based on their sizes such as nano, micro, and macro systems, and for each of the reviewed systems, design, formulation strategies, and drug release performance has been discussed.

Ketamine-polymer based drug delivery system for prolonged analgesia: recent advances, challenges and future prospects

Introduction: With a sharp increase in NSAIDs and opioid use for chronic pain conditions associated with traumatic injuries and diseases, there has been an escalated risk of life-threatening side effects (cardiac and respiratory malfunction), inadvertent overdose, and even death. Their short duration of action and toxicity induces the need to develop extended-release analgesic drug formulations based on safe drugs like ketamine.Areas covered: This review presents progressive breakthroughs in pain control strategies for augmenting patient's comfort and minimizing unnecessary adverse effects associated with NSAIDs and opioids. Advantages of using ketamine, a dissociative anesthetic and potent analgesic over opioids have been elaborated here for the development of advanced sustained-release analgesic drug formulations based on ketamine and polymers (hydrogels, microparticles, and nanoparticles) as mainstream systems. These systems can be very promising in the resource-constrained healthcare set-up where frequent drug dosing at short time intervals is extremely challenging. PubMed, Embase, Google Scholar electronic databases, and clinical websites were used for conducting extensive research.Expert opinion: Controlled drug release analgesic systems can significantly reduce the burden of repeated drug dosing and opioid drug dependency, maximizing the function of analgesic drugs for clinical translation, and improving the quality of life of those living with pain.

Use of Microfluidics to Fabricate Bioerodable Lipid Hybrid Nanoparticles Containing Hydromorphone or Ketamine for the Relief of Intractable Pain

PURPOSE

For patients with intractable cancer-related pain, administration of strong opioid analgesics and adjuvant agents by the intrathecal (i.t.) route in close proximity to the target receptors/ion channels, may restore pain relief. Hence, the aim of this study was to use bioerodable polymers to encapsulate an opioid analgesic (hydromorphone) and an adjuvant drug (ketamine) to produce prolonged-release formulations for i.t. injection.

METHODS

A two-stage microfluidic method was used to fabricate nanoparticles (NPs). The physical properties were characterised using dynamic light scattering and transmission electron microscopy. A pilot in vivo study was conducted in a rat model of peripheral neuropathic pain.

RESULTS

The in vitro release of encapsulated payload from NPs produced with a polymer mixture (CPP-SA/PLGA 50:50) was sustained for 28 days. In a pilot in vivo study, analgesia was maintained over a three day period following i.t. injection of hydromorphone-loaded NPs at 50 μg. Co-administration of ketamine-loaded NPs at 340 μg did not increase the duration of analgesia significantly.

CONCLUSIONS

The two-stage microfluidic method allowed efficient production of analgesic/adjuvant drug-loaded NPs. Our proof-of-principle in vivo study shows prolonged hydromorphone analgesic for 78 h after single i.t. injection. At the i.t. dose administered, ketamine released from NPs was insufficient to augment hydromorphone analgesia.