Bioequivalence of Canakinumab Injected Subcutaneously via an Autoinjector Device or a Prefilled Safety Syringe Device in Healthy Subjects.

Canakinumab, a high-affinity human anti-interleukin-1ß monoclonal antibody, is being used for the treatment of a broad spectrum of inflammatory diseases. This phase 1 study compared the relative bioavailability of a single dose of subcutaneous canakinumab either self-administered with an autoinjector (AI) or administered by a health care professional (HCP) with a prefilled safety syringe (SS) in healthy subjects. The study enrolled 80 subjects randomized 1:1 to receive 150 mg/mL of a liquid formulation of canakinumab via an AI or SS into either the thigh or abdomen. The geometric mean ratio (90% confidence interval [CI]) of Cmax was 1.09 (0.97-1.21), AUClast was 1.06 (0.96-1.17), and AUCinf was 1.05 (0.94-1.18) for the AI versus SS. The 2-sided 90%CIs that compared self-administration with the AI versus administration by an HCP using the SS were entirely within the bioequivalence limits of 80%-125%. Two subjects in the AI group and 1 in the SS group experienced mild injection-site reactions. No immunogenicity response was detected in the 307 samples analyzed for immunogenicity. No discontinuations because of adverse events were reported in this trial. Canakinumab administration with an AI or SS has a comparable bioavailability, meeting bioequivalence criteria.

Population Pharmacokinetics of Tobramycin Inhalation Solution in Pediatric Patients With Cystic Fibrosis.

Tobramycin inhalation solution given as a twice daily inhalation of nebulized aerosols of 300 mg is approved for the treatment of Pseudomonas aeruginosa infection in cystic fibrosis patients over 6 years of age. To investigate tobramycin pharmacokinetics (PK) after inhalation of tobramycin in pediatric cystic fibrosis patients below 7 years, a population PK approach was used to evaluate tobramycin PK data in patients 6 months to 44 years of age from 4 clinical studies. The final model used a 2-compartmental, first-order absorption model with effect of body mass index on the apparent central volume of distribution. Relative bioavailability in patients between 6 months and 7 years increased with age by a linear relationship, and was modeled as a ratio to that of patients over 7 years. Simulation showed that steady-state concentrations of tobramycin are lower in pediatric patients 6 months to 6 years than those in patients over 6 years. However, systemic exposure is not predictive of clinical efficacy due to direct dosing at the infection site. P aeruginosa eradication rate and safety profile in patients less than 7 years of age were similar to patients older than 6 years; therefore, no dose adjustment is warranted in the younger pediatric patients.

Doxycycline hydrogels with reversible disulfide crosslinks for dermal wound healing of mustard injuries.

Doxycycline hydrogels containing reversible disulfide crosslinks were investigated for a dermal wound healing application. Nitrogen mustard (NM) was used as a surrogate to mimic the vesicant effects of the chemical warfare agent sulfur mustard. An 8-arm-poly(ethylene glycol) (PEG) polymer containing multiple thiol (-SH) groups was crosslinked using hydrogen peroxide (H(2)O(2) hydrogel) or 8-arm-S-thiopyridyl (S-TP hydrogel) to form a hydrogel in situ. Formulation additives (glycerin, PVP and PEG 600) were found to promote dermal hydrogel retention for up to 24 h. Hydrogels demonstrated high mechanical strength and a low degree of swelling (< 1.5%). Doxycycline release from the hydrogels was biphasic and sustained for up to 10-days in vitro. Doxycycline (8.5 mg/cm(3)) permeability through NM-exposed skin was elevated as compared to non vesicant-treated controls at 24, 72 and 168 h post-exposure with peak permeability at 72 h. The decrease in doxycycline permeability at 168 h correlates to epidermal re-epithelialization and wound healing. Histology studies of skin showed that doxycycline loaded (0.25% w/v) hydrogels provided improved wound healing response on NM-exposed skin as compared to untreated skin and skin treated with placebo hydrogels in an SKH-1 mouse model. In conclusion, PEG-based doxycycline hydrogels are promising for dermal wound healing application of mustard injuries.

Doxycycline hydrogels as a potential therapy for ocular vesicant injury.

PURPOSE: The goals of this study were (1) to compare the injury at the basement membrane zone (BMZ) of rabbit corneal organ cultures exposed to half mustard (2 chloroethyl ethyl sulfide, CEES) and nitrogen mustard with that of in vivo rabbit eyes exposed to sulfur mustard (SM); (2) to test the efficacy of 4 tetracycline derivatives in attenuating vesicant-induced BMZ disruption in the 24-h period postexposure; and (3) to use the most effective tetracycline derivative to compare the improvement of injury when the drug is delivered as drops or hydrogels to eyes exposed in vivo to SM. METHODS: Histological analysis of hematoxylin and eosin­stained sections was performed; the ultrastructure of the corneal BMZ was evaluated by transmission electron microscopy; matrix metalloproteinase-9 was assessed by immunofluorescence; doxycycline as drops or a hydrogel was applied daily for 28 days to eyes exposed in vivo to SM. Corneal edema was assessed by pachymetry and the extent of neovascularization was graded by length of longest vessel in each quadrant. RESULTS: Injury to the BMZ was highly similar with all vesicants, but varied in degree of severity. The effectiveness of the 4 drugs in retaining BMZ integrity did not correlate with their ability to attenuate matrix metalloproteinase-9 expression at the epithelial­stromal border. Doxycycline was most effective on organ cultures; therefore, it was applied as drops or a hydrogel to rabbit corneas exposed in vivo to SM. Eyes were examined at 1, 3, 7, and 28 days after exposure. At 7 and 28 days after SM exposure, eyes treated with doxycycline were greatly improved over those that received no therapy. Corneal thickness decreased somewhat faster using doxycycline drops, whereas the hydrogel formulation decreased the incidence of neovascularization. CONCLUSIONS: Corneal cultures exposed to 2-chloroethyl ethyl sulfide and nitrogen mustard were effective models to simulate in vivo SM exposures. Doxycycline as drops and hydrogels ameliorated vesicant injury. With in vivo exposed animals, the drops reduced edema faster than the hydrogels, but use of the hydrogels significantly reduced neovascularization. The data provide proof of principle that a hydrogel formulation of doxycycline as a daily therapy for ocular vesicant injury should be further investigated.

Doxycycline loaded poly(ethylene glycol) hydrogels for healing vesicant-induced ocular wounds.

Half mustard (CEES) and nitrogen mustard (NM) are commonly used surrogates and vesicant analogs of the chemical warfare agent sulfur mustard. In the current study, in situ forming poly(ethylene glycol) (PEG)-based doxycycline hydrogels are developed and evaluated for their wound healing efficacy in CEES and NM-exposed rabbit corneas in organ culture. The hydrogels, characterized by UV-Vis spectrophotometry, rheometry, and swelling kinetics, showed that the hydrogels are optically transparent, have good mechanical strength and a relatively low degree of swelling (<7%). In vitro doxycycline release from the hydrogel disks (0.25% w/v) was found to be biphasic with release half times of approximately 12 and 72h, respectively, with 80-100% released over a 7-day period. Permeation of doxycycline through vesicant wounded corneas was found to be 2.5 to 3.4 fold higher than non-wounded corneas. Histology and immunofluorescence studies showed a significant reduction of matrix metalloproteinase-9 (MMP-9) and improved healing of vesicant-exposed corneas by doxycycline hydrogels compared to a similar dose of doxycycline delivered in phosphate buffered saline (PBS, pH 7.4). In conclusion, the current studies demonstrate that the doxycycline-PEG hydrogels accelerate corneal wound healing after vesicant injury offering a therapeutic option for ocular mustard injuries.

Design and evaluation of novel fast forming pilocarpine-loaded ocular hydrogels for sustained pharmacological response.

Fast forming hydrogels prepared by crosslinking a poly(ethylene glycol) (PEG)-based copolymer containing multiple thiol (SH) groups were evaluated for the controlled ocular delivery of pilocarpine and subsequent pupillary constriction. Physical properties of the hydrogels were characterized using UV-Vis spectrophotometry, transmission electron microscopy (TEM), rheometry, and swelling kinetics. Pilocarpine loading efficiency and release properties were measured in simulated tear fluid. The hydrogel formulations exhibited high drug loading efficiency (approximately 74%). Pilocarpine release was found to be biphasic with release half times of approximately 2 and 94 h, respectively, and 85-100% of the drug was released over 8-days. Pilocarpine-loaded (2% w/v) hydrogels were evaluated in a rabbit model and compared to a similar dose of drug in aqueous solution. The hydrogels were retained in the eye for the entire period of the study with no observed irritation. Pilocarpine-loaded hydrogels sustained pupillary constriction for 24 h after administration as compared to 3 h for the solution, an 8-fold increase in the duration of action. A strong correlation between pilocarpine release and pupillary response was observed. In conclusion, the current studies demonstrate that in situ forming PEG hydrogels possess the viscoelastic, retention, and sustained delivery properties required for an efficient ocular drug delivery system.