Infliximab stability after reconstitution, dilution, and storage under refrigeration

A comprehensive review of intravitreal immunosuppressants and biologicals used in ophthalmology

Systemic immunosuppressants and biologicals have been a valuable tool in the treatment of inflammatory diseases and malignancies. The safety profile of these drugs has been debatable, especially in localized systems, such as the eye. This has led to the search for fairly local approaches, such as intravitreal, subconjunctival, and topical route of administration. Immunosuppressants have been used as a second-line drug in patients intolerable to corticosteroids or those who develop multiple recurrences on weaning corticosteroids. Similarly, biologicals have also been used as the next line of therapy, when adequate control of inflammation could not be attained or immunosuppressants were contraindicated to patients. Intravitreal immunosuppressants, such as methotrexate and sirolimus, have been extensively studied in noninfectious posterior uveitis, whereas limited studies have established the efficacy of intravitreal biologicals, such as infliximab and adalimumab. Most of these drugs have shown good safety profile and tolerability in animal studies alone and have not been studied further in human subjects. However, most of the studies in literature are single-case reports or case series which limits the level of evidence. In this comprehensive review, we discuss the mechanism of action, pharmacodynamics, pharmacokinetics, indications, efficacy, and side effects of different intravitreal immunosuppressants and biologicals that have been studied in literature.

INTRAVITREAL INFLIXIMAB IN REFRACTORY UVEITIS IN BEHCET'S DISEASE: A Safety and Efficacy Clinical Study

PURPOSE

To assess the safety and efficacy of intravitreal infliximab (1 mg/0.05 mL) in patients with refractory posterior uveitis in Behcet's disease.

METHODS

Twenty patients were included in this study. Best corrected visual acuity (BCVA), vitreous haze (graded 0-4), vasculitis, retinitis, and papillopathy (presence or absence) were assessed at baseline, Day 1 and Week 2, 4, 6, 8, 12, and 18. Optical coherence tomography (OCT) central foveal thickness, fluorescein angiography, and flash electroretinogram were done at baseline and 4, 12, and 18 weeks.

RESULTS

Mean baseline logMAR BCVA was 0.94 (20/160), had improved significantly by Week 2 to 0.6 (20/80) (P < 0.0001), and reached 0.36 (20/40) by Weeks 18 with three injections (P < 0.0001). Mean central foveal thickness OCT decreased significantly from baseline 361 μm to 180 μm at the end of follow-up (P < 0.0001). Profound decrease in mean vitreous haze gradings from two to 0.2 by the end follow-up (P < 0.05). There was a significant reduction in the number of patients with vasculitis (15 at baseline to 1 weeks at 18 weeks), retinitis (nine at baseline to none at 4 weeks), and papillitis (two at baseline to none at 4 weeks) (P < 0.05). No significant electrophysiological changes or ocular adverse inflammatory reactions were observed during the study period.

CONCLUSION

Intravitreal infliximab appeared to be safe and effective in treating uveitis in Behcet's disease and should be considered as an alternative to systemic therapies.

Capillary electrophoresis for rapid identification of monoclonal antibodies for routine application in hospital

mAbs are widely used in cancer therapy. Their compounding, performed just before their administration to patients, is executed in a production unit of the hospital. Identification of these drugs, individually prepared in bags for infusion before patient administration, is of paramount importance to detect potential mistakes during compounding stage. A fast and reliable analytical method based on CZE combined to a cationic capillary coating (hexadimethrine bromide) was developed for identification of the most widely used compounded therapeutic for cancer therapy (bevacizumab, cetuximab, rituximab, and trastuzumab). Considering the high structural and physico-chemical similarities of these mAbs, an extensive optimization of the BGE composition has been performed. The addition of perchlorate ions and polysorbate in the BGE greatly increased the resolution. To validate the method, an internal standard was used and the relative migration times (RTm) were estimated. Very satisfactory RSDs of the RTm for rituximab (0.76%), cetuximab (0.46%), bevacizumab (0.31%), and trastuzumab (0.60%) were obtained. The intraday and interday RSD of the method were less than 0.32 and 1.3%, respectively for RTm. Significant differences between theses RTms have been demonstrated allowing mAbs identification. Finally, accurate mAbs identification has been demonstrated by a blind test.

Development of a stable low-dose aglycosylated antibody formulation to minimize protein loss during intravenous administration

The physical and chemical integrity of a biopharmaceutical must be maintained not only during long-term storage but also during administration. Specifically for the intravenous (i.v.) delivery of a protein drug, loss of stability can occur when the protein formulation is compounded with i.v. bag diluents, thus modifying the original composition of the drug product. Here we present the challenges associated with the delivery of a low-dose, highly potent monoclonal antibody (mAb) via the i.v. route. Through parallel in-use stability studies and conventional formulation development, a drug product was developed in which adsorptive losses and critical oxidative degradation pathways were effectively controlled. This development approach enabled the i.v. administration of clinical doses in the range of 0.1 to 0.5 mg total protein, while ensuring liquid drug product storage stability under refrigerated conditions.

Update on intravitreal anti-tumor necrosis factor alpha therapies for ocular disorders

Tumor necrosis factor alpha (TNF-?) is an important pro-inflammatory cytokine associated with a variety of ocular diseases. The currently available TNF-? inhibitors are etanercept, infliximab, adalimumab, golimumab, and certolizumab. Experimental and clinical studies on the intravitreal use of these agents have been reported with etanercept, infliximab, and adalimumab: etanercept has shown limited efficacy in scarce reports; infliximab has been associated with local safety concerns but appears to benefit certain cases; adalimumab has shown no efficacy in cases of age-related macular degeneration (AMD) or diabetic macular edema (DME), but the combination with bevacizumab may be effective in refractory cases of macular diseases. Further preclinical and clinical studies are warranted in order to be able to obtain a more robust conclusion on the use of intravitreal TNF-? inhibitors.

Evaluations of therapeutic efficacy of intravitreal injected polylactic-glycolic acid microspheres loaded with triamcinolone acetonide on a rabbit model of uveitis

Conventional treatments of uveitis are not ideal because of the short period of therapeutic efficacy. In the present study, biodegradable polylactic-glycolic acid microspheres loaded with triamcinolone acetonide (TA) were prepared to achieve sustained drug release and their therapeutic efficacy was investigated on a rabbit model of uveitis. TA-loaded microspheres (TA-MS) were prepared by the solvent evaporation method and characterized for encapsulation efficiency, particle size, morphology and in vitro release. The therapeutic efficacy was studied on the rabbit experimental uveitis model based on scoring of the inflammation, aqueous leukocyte counting, aqueous protein determination and histological examination. The TA-MS exhibited smooth and intact surfaces with an average diameter of 50.87 μm. The drug-loading coefficient and encapsulation efficiency were 15.2 ± 0.6 % and 91.24 ± 3.77 %, respectively. The drug release from TA-MS lasted up to 87 days, but only 46 days for TA suspension. The change in surface morphology also showed sustained drug release from TA-MS. TA-MS exhibited improved therapeutic efficacy in lipopolysaccharide -induced uveitis compared to TA suspension, especially in regard to the inhibition of inflammation. The TA-MS had a longer-term therapeutic effect on intraocular inflammation in LPS-induced uveitis in rabbits compared to TA suspension. The results suggested that TA-MS can be developed as a potential sustained-release system for the treatment of uveitis.

Stability of infliximab in polyvinyl chloride bags

PURPOSE

The stability of prepared infusions of the tumor necrosis factor (TNF)-α agent infliximab after storage for up to two weeks was investigated.

METHODS

To determine the feasibility of liberalized expiration dating of infliximab (current recommendations call for the infusion of prepared doses within three hours), the stability of diluted infliximab stored in polyvinyl chloride (PVC) bags at 4 °C for up to 14 days was evaluated. A known quantity of TNF-α was combined with infliximab test samples in PVC bags for one hour; immediately after the reaction period and after 7 and 14 days of storage, the residual amount of TNF-α (an indirect measure of the drug's biological activity) was analyzed via a validated enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean ± S.D. amount of TNF-α consumed by infliximab was calculated to be 24.5 ± 5.6 pg/mL at baseline, 29.0 ± 4.4 pg/mL at 7 days, and 24.8 ± 17.3 pg/mL at 14 days. At all evaluated time points, ELISA results indicated that 19-24% of the original TNF-α had been consumed by infliximab (mean ± S.D. consumption: 19.6% ± 4.5% at baseline, 23.2% ± 3.5% at 7 days, and 19.8% ± 13.8% at 14 days).

CONCLUSION

Infliximab, when prepared at a concentration of 400 μg/mL in 0.9% sodium chloride injection, incurred no loss of biological activity when stored for up to 14 days at 4 °C in PVC bags. Changing infliximab preparation practices may improve clinic efficiency by reducing patient dissatisfaction with long wait times for infusions and avoiding costly waste.