In vivo evaluation of risperidone-SAIB in situ system as a sustained release delivery system in rats

Exploring the mucoadhesive behavior of sucrose acetate isobutyrate: a novel excipient for oral delivery of biopharmaceuticals

Oral drug delivery is an attractive noninvasive alternative to injectables. However, oral delivery of biopharmaceuticals is highly challenging due to low stability during transit in the gastrointestinal tract (GIT), resulting in low systemic bioavailability. Thus, novel formulation strategies are essential to overcome this challenge. An interesting approach is increasing retention in the GIT by utilizing mucoadhesive biomaterials as excipients. Here, we explored the potential of the GRAS excipient sucrose acetate isobutyrate (SAIB) to obtain mucoadhesion in vivo. Mucoadhesive properties of a 90% SAIB/10% EtOH (w/w) drug delivery system (DDS) were assessed using a biosimilar mucus model and evaluation of rheological behavior after immersion in biosimilar intestinal fluid. To ease readability of this manuscript, we will refer to this as SAIB DDS. The effect of SAIB DDS on cell viability and epithelial membrane integrity was tested in vitro prior to in vivo studies that were conducted using SPECT/CT imaging in rats. When combining SAIB DDS with biosimilar mucus, increased viscosity was observed due to secondary interactions between biosimilar mucus and sucrose ester predicting considerable mucoadhesion. Mucoadhesion was confirmed in vivo, as radiolabeled insulin entrapped in SAIB DDS, remained in the small intestine for up to 22 h after administration. Moreover, the integrity of the system was investigated using the dynamic gastric model under conditions simulating the chemical composition of stomach fluid and physical shear stress in the antrum under fasted conditions. In conclusion, SAIB is an interesting and safe biomaterial to promote high mucoadhesion in the GIT after oral administration.

Delivery of radix ophiopogonis polysaccharide via sucrose acetateisobutyrate-based in situ forming systems alone or combined with itsmono-PEGylation

This work aimed to achieve long-lasting delivery of radix ophiopogonis polysaccharide (ROP) by sucrose acetate isobutyrate (SAIB)-based in situ forming systems (ISFSs) alone or combined with mono-PEGylation of ROP. When the ‘90%SAIB/10% solvent’ system was used, the mean residence time (MRT) of ROP was prolonged by 4.3 5 ∼ 7.00 times and the initial release rate was reduced significantly. However, this system was only suitable for days-long sustained release of ROP in short-term therapy. As to the ‘SAIB/additives/solvent’ system containing mono-PEGylated ROP, the results indicated that SAIB/poly(d,l-lactide-co-glycolide) (PLGA)/N-methyl-2-pyrrolidone (NMP) was superior to SAIB/polylactic acid (PLA)/NMP and SAIB/PLA/ethanol in controlled release. Moreover, weeks- to months-long (16–60 d) smooth release of ROP could be achieved by varying the concentration (10–30%) and molecular weight (MW) of PLGA (10–50 kDa) or by employing a moderate MW of PEGylated ROP (∼20 or ∼30 kDa). With further increasing the conjugate MW to ∼40 kDa, the contribution of drug elimination to its plasma retention seemed to surpass that of the SAIB-based system, resulting in that the system no longer had an obvious influence on the in vivo behavior of the conjugate. Besides, the results of host response confirmed that with less solvent being used, the SAIB-based systems showed a higher biocompatibility than the PLGA-based systems, suggesting that they could be freely chosen in the prevention and/or cure of chronic diseases.

Recent advances in abuse-deterrent technologies for the delivery of opioids

Over the past decade, the abuse of prescription opioid drugs has become a national health crisis in the United States. Pharmaceutical companies, the Food and Drug Administration, and other government agencies are confronting opioid abuse by developing and commercializing various abuse-deterrent drug delivery technologies. To deter opioid abuse, various strategies including physical barriers, chemical barriers, antagonists, aversive agents, and prodrugs have been investigated. A number of drug products with abuse-deterrent properties have been approved by the FDA over the last six years, while many products and technologies with progressively-improved abuse-deterrence properties are currently being evaluated. This article provides a comprehensive review of the material sciences principles that govern the formulation and processing of a wide range of abuse-deterrent products and technologies.

A Uniform Ultra-Small Microsphere/SAIB Hybrid Depot with Low Burst Release for Long-Term Continuous Drug Release

PURPOSE

In the present study, a uniform ultra-small microsphere/sucrose acetate isobutyrate (SAIB) hybrid depot (m-SAIB depot) was designed to provide a long-term sustained release drug delivery system which not only reduced the burst release of an SAIB depot, but also eliminated the lag-time of PLGA microspheres.

METHODS

Risperidone loaded m-SAIB depot (Ris-m-SAIB depot) was characterized by in vitro drug release, pharmacokinetics, in vivo degradation and biocompatibility, in comparison with risperidone loaded SAIB depot (Ris-SAIB depot).

RESULTS

Ris-m-SAIB depot showed a low burst release (0.64%) and a reduced in vitro drug release rate due to the encapsulation of most drug in microspheres. After intramuscular administration, the in vivo burst release of Ris-m-SAIB was significantly decreased, as reflected by the low Cmax/Cs(4-td) (approximately 30-fold reduction), in comparison with Ris-SAIB depot. From 4 to 78 days, Ris-m-SAIB depot showed a higher plasma drug level (1.55 ~ 16.30 ng/ml) with a steadier drug release profile compared with Ris-SAIB depot. Ris-m-SAIB depot degraded gradually with a degradation t1/2 of 54.6 days and exhibited good biocompatibility in vivo.

CONCLUSION

These results demonstrate the potential application of a uniform ultra-small microsphere/SAIB hybrid depot for continuously delivering small drug molecules for long periods of time without burst release.

Injectable implants for the sustained release of protein and peptide drugs

Protein and peptide macromolecules have emerged as promising therapeutic agents in recent years. However, their delivery to the target site can be challenging owing to their susceptibility to denaturation and degradation, short half-life and, therefore, poor bioavailability. In situ-forming implants present an attractive parenteral delivery platform for proteins and peptides because of their ease of application, sustained-release properties, tissue biocompatibility and simple manufacture. In this review, we discuss the various mechanisms by which polymer systems assemble in situ to form implant devices for sustained release of therapeutic macromolecules, and highlight recent advances in polymer systems that gel in response to a combination of these mechanisms. Finally, we examine release mechanisms, marketed products and limitations of injectable implants.

A novel risperidone-loaded SAIB-PLGA mixture matrix depot with a reduced burst release: effects of solvents and PLGA on drug release behaviors in vitro/in vivo

The purpose of this study was to develop an in situ forming SAIB (sucrose acetate isobutyrate)-PLGA (poly (d, lactide-co-glycolide)) mixture matrix depot for sustained release of risperidone. The factors affecting the risperidone release kinetics were investigated to obtain further insight into the drug release mechanisms. The burst release in vitro was significantly reduced (4.95%) by using DMSO as solvent. And, increasing the PLGA content from 2 to 10% w/w decreased the initial release from 6.95 to 1.05%. The initial release in vivo decreased with increasing PLGA content (2.0% w/w PLGA, C(max) = 1161.7 ± 550.2 ng ml(-1); 10% w/w PLGA, C(max) = 280.3 ± 98.5 ng ml(-1)). The persistence (AUC(4-20 days)) over 20 days increased from 76.8 ± 20.7 to 362.8 ± 75.0 ng d ml(-1) by inclusion of 10% PLGA compared with the PLGA-free depot. These results demonstrate that the SAIB-PLGA mixture matrix depot could be useful as a sustained delivery system for risperidone.

Materials for pharmaceutical dosage forms: molecular pharmaceutics and controlled release drug delivery aspects

Controlled release delivery is available for many routes of administration and offers many advantages (as microparticles and nanoparticles) over immediate release delivery. These advantages include reduced dosing frequency, better therapeutic control, fewer side effects, and, consequently, these dosage forms are well accepted by patients. Advances in polymer material science, particle engineering design, manufacture, and nanotechnology have led the way to the introduction of several marketed controlled release products and several more are in pre-clinical and clinical development.