Development and characterization of multivesicular liposomes bearing serratiopeptidase for sustained delivery

Advances and challenges in serratiopeptidase topical formulation

Enzymes are a key part of most metabolic processes and are required for the correct functioning of the human body, either directly or indirectly. Proteolytic enzymes aid in the digestion of proteins in the body. Proteolytic enzymes are created in the pancreas naturally, but they can also be found in certain diets. Serratiopeptidase is an enzyme found in the stomach wall of silkworms and produced from S. marcescens strain. Less solubility, toxicity, instability, incompatibility, and less penetration are all common issues with Serratiopeptidase drug delivery. Because of its proteinaceous nature, serratiopeptidase is susceptible to enzymatic breakdown in the gastrointestinal system. It also has a low permeability through the intestinal barrier due to its hydrophilic nature. Depending on the features of the medicine, a suitable delivery mechanism is required. Topical formulation may eliminate the risk of gastric degradation of drug and increase direct permeation through skin and show effects. Topical SRP may effectively lower inflammatory markers, as it has been found to have superior anti-inflammatory effects than topical NSAIDs. Serratiopeptidase topical formulations could be more effective than nonsteroidal anti-inflammatory medications in treating local inflammation. This article reviews studies on various topical formulations.

Preparation of multivesicular liposomes for the loco-regional delivery of Vancomycin hydrochloride using active loading method: drug release and antimicrobial properties

Over the last few years, among controlled-release delivery systems, multivesicular liposomes (MVLs) have attracted attention due to their unique benefits as a loco-regional drug delivery system. Considering the clinical limitations of the current treatment strategies for osteomyelitis, MVLs can be a suitable carrier for the local delivery of effective antibiotics. This study aimed to prepare vancomycin hydrochloride (VAN HL) loaded MVLs using the active loading method which to the best of our knowledge has not been previously reported. Empty MVLS were prepared by the double emulsion (w/o/w) method and VAN HL was loaded into the prepared liposomes by the ammonium gradient method. After full characterization, the release profile of VAN HL from MVLs was assessed at two different pH values (5.5 and 7.4), and compared with the release profile of the free drug and also passively loaded MVLs. In vitro antimicrobial activities were evaluated using the disc diffusion method. Our results demonstrated that the encapsulation efficiency was higher than 90% in the optimum actively loaded MVL. The free VAN HL was released within 6-8 h, while the passively loaded MVLs and the optimum actively loaded MVL formulation released the drug in 6 days and up to 19 days, respectively. The released drug showed effective antibacterial activity against osteomyelitis-causing pathogens. In conclusion, the prepared formulation offered the advantages of sustained-release properties, appropriate particle size as well as being composed of biocompatible materials, and thus could be a promising candidate for the loco-regional delivery of VAN HL and the management of osteomyelitis.

Multivesicular liposomal depot system for sustained delivery of risperidone: development, characterization, and toxicity assessment

OBJECTIVE

Considering the limitations of conventional risperidone (RSP) therapies, the present research characterizes the usefulness of multivesicular liposomes (MVLs) as an efficient controlled-release carrier for this widely used antipsychotic drug, to be employed for the treatment of schizophrenia.

METHODS

A 2³ full factorial design based on three independent variables was implemented to plan the experiments: the molar ratios of lipid to the drug, triolein to phospholipid, and cholesterol to phospholipid. The impacts of these parameters on the risperidone encapsulation efficiency and its release pattern within the first 24 and 48 h were investigated as dependent variables. Then, the optimized liposomal system was further in-depth analyzed in terms of size, morphological and structural features, release profile over 15 days, biocompatibility, and stability.

RESULTS

Optimized formulation parameters gave rise to MVLs possessing a spherical morphology with a median diameter of about 8 μm, a relatively narrow size distribution (span value of 1.49), and an encapsulation efficiency of 57.6%. These carriers not only exhibited a sustained-release behavior in vitro, lasting until the end of the 15 days but also underwent a negligible change in their size and RSP incorporation over two months at refrigerator condition. Furthermore, in vitro cytotoxicity and hemolysis assessments revealed that the optimized MVL formulation is biocompatible.

CONCLUSION

This study revealed the potential of MVLs as a promising system for the delivery of RSP and could open a new vista for the successful management of schizophrenia.

Preparation and Evaluation of Intraperitoneal Long-Acting Oxaliplatin-Loaded Multi-Vesicular Liposomal Depot for Colorectal Cancer Treatment

Colorectal cancer with peritoneal metastasis has a poor prognosis because of inadequate responses to systemic chemotherapy. Cytoreductive surgery followed by intraperitoneal (IP) chemotherapy using oxaliplatin has attracted attention; however, the short half-life of oxaliplatin and its rapid clearance from the peritoneal cavity limit its clinical application. Here, a multivesicular liposomal (MVL) depot of oxaliplatin was prepared for IP administration, with an expected prolonged effect. After optimization, a combination of phospholipids, cholesterol, and triolein was used based on its ability to produce MVL depots of monomodal size distribution (1–20 µm; span 1.99) with high entrapment efficiency (EE) (92.16% ± 2.17%). An initial burst release followed by a long lag phase of drug release was observed for the MVL depots system in vitro. An in vivo pharmacokinetic study mimicking the early postoperative IP chemotherapy regimen in rats showed significantly improved bioavailability, and the mean residence time of oxaliplatin after IP administration revealed that slow and continuous erosion of the MVL particles yielded a sustained drug release. Thus, oxaliplatin-loaded MVL depots presented in this study have potential for use in the treatment of colorectal cancer.

Serratiopeptidase Niosomal Gel with Potential in Topical Delivery

The objective of present study was to develop nonionic surfactant vesicles of proteolytic enzyme serratiopeptidase (SRP) by adapting reverse phase evaporation (REV) technique and to evaluate the viability of SRP niosomal gel in treating the topical inflammation. The feasibility of SRP niosomes by REV method using Span 40 and cholesterol has been successfully demonstrated in this investigation. The entrapment efficiency was found to be influenced by the molar ratio of Span 40 : cholesterol and concentration of SRP in noisome. The developed niosomes were characterized for morphology, particle size, and in vitro release. Niosomal gel was prepared by dispersing xanthan gum into optimized batch of SRP niosomes. Ex vivo permeation and in vivo anti-inflammatory efficacy of gel formulation were evaluated topically. SRP niosomes obtained were round in nanosize range. At Span 40 : cholesterol molar ratio 1 : 1 entrapment efficiency was maximum, that is, 54.82% ± 2.08, and showed consistent release pattern. Furthermore ex vivo skin permeation revealed that there was fourfold increase in a steady state flux when SRP was formulated in niosomes and a significant increase in the permeation of SRP, from SRP niosomal gel containing permeation enhancer. In vivo efficacy studies indicated that SRP niosomal gel had a comparable topical anti-inflammatory activity to that of dicolfenac gel.