Semiquantitative sensitization safety assessment of extractable and leachables associated with parenteral pharmaceutical products.

Extractable and leachables (E&Ls) associated with parenteral pharmaceutical products should be assessed for patient safety. One essential safety endpoint is local or systemic sensitization. However, there are no regulatory guidelines for quantitative sensitization safety assessment of E&Ls. A semiquantitative sensitization safety assessment workflow is developed to refine the sensitization safety assessment of E&Ls associated with parenteral pharmaceutical products. The workflow is composed of two sequential steps: local skin sensitization and systemic sensitization safety assessment. The local skin sensitization step has four tiers. The output from this step is the acceptable exposure level for local sensitization (AELls) and this safety threshold can be used for local sensitization safety assessment. From the derived AELls, the systemic sensitization safety assessment at step 2 proceeds in 2 tiers. The output from this workflow is the derivation of acceptable exposure level for systemic sensitization (AELss). When the estimated human daily exposure (HDE) is compared with the AELss, the margin of exposure is calculated to determine the sensitization safety of E&Ls following parenteral administration. The current work represents an initial effort to develop a scientifically robust process for sensitization safety assessment of E&Ls associated with parenteral pharmaceutical products.

An in vivo comparison of the efficacy of hemostatic powders, using two porcine bleeding models.

BACKGROUND: Usage of topical hemostatic agents in surgery is increasing, including use during minimally invasive procedures, and even for surgeries that have a low risk of bleeding complications. A novel product, Surgicel® Powder - Absorbable Hemostatic Powder (SP), made from oxidized regenerated cellulose (ORC) fabric, has been developed for adjunctive use in surgical procedures to assist in control of oozing bleeding over broad areas and where access could be difficult with a fabric ORC product. This study compares the new SP to other commercially available hemostatic powder products in two in vivo models. METHODS: Hemostatic efficacy of SP was compared to two polysaccharide-based hemostats in a porcine liver punch biopsy model and to three polysaccharide-based hemostats and one non-regenerated oxidized cellulose hemostat in a porcine liver abrasion model. Primary outcomes measured were hemostatic efficacy, defined as hemostasis within 10 minutes of application, and time-to-hemostasis (TTH). RESULTS: In the punch biopsy model, SP displayed significantly higher effective hemostasis rates than one of the polysaccharide hemostats (p=0.047) and faster TTH than both (p<0.001). In the liver abrasion model, SP had significantly higher effective hemostasis rates (p≤0.002) and faster TTH (p<0.001) than the other four hemostatic agents. The amount of powder applied within the ranges used did not appear to affect hemostatic efficacy. CONCLUSION: In both the liver punch biopsy model of mild to moderate bleeding and the liver abrasion model of mild but diffuse oozing, SP provided more effective hemostasis and faster TTH than other marketed hemostatic powders. The results from this in vivo study suggest that Surgicel Powder may be useful in clinical applications where control of oozing capillary, mild venous, and small arterial hemorrhage is required including bleeding in difficult-to-access locations.

An In Vivo Comparison of Hemostatic Gelatin Matrix Products in a Porcine Spleen Biopsy-punch Model.

Flowable gelatin matrix products have established themselves as effective, easy-to-use hemostatic agents useful in a variety of surgical situations. A recently reformulated gelatin matrix, Surgiflo® (Ethicon Inc., Somerville, NJ), can be prepared quickly and provides consistent flow over an 8-hr. period. No in vivo studies have yet been reported comparing hemostasis with the new Surgiflo to other currently marketed flowable gelatin matrix products. This study was conducted to determine whether Surgiflo in actual use has hemostatic qualities different from another commercial gelatin matrix. An in vivo model based on porcine spleen biopsy punch-induced bleeding was used to compare Surgiflo and Floseal™ (Baxter Healthcare Corporation, Hayward, CA), both with thrombin. Time required to achieve hemostasis and proportion of sites achieving hemostasis within 30 s were determined for both hemostatic agents and a control of saline-soaked gauze. Results were stratified by the degree of initial bleeding (mild, moderate, severe). Hemostasis was achieved within 3 minutes at all sites for both test products regardless of level of initial bleeding, and control sites continued bleeding past 10 minutes. There were no statistically significant differences between Surgiflo and Floseal for either mean time to hemostasis or proportion of sites hemostatic within 30 s. In this realistic in vivo model both gelatin matrix products were effective, and there were no significant differences observed in hemostatic efficacy between Surgiflo and Floseal. Other factors, such as ease of preparation and application, in-use stability, and economic considerations may affect a surgeon's decision in selection of a desirable hemostatic product.

Evaluation of fibrin sealants for central nervous system sealing in the mongrel dog durotomy model.

BACKGROUND: Watertight repair of the dura is imperative after neurosurgical procedures involving the brain or spinal cord because inadequately treated leakage of cerebrospinal fluid (CSF) from punctured dura can have serious consequences such as meningitis, arachnoiditis, or epidural abscess. OBJECTIVE: To assess the efficacy of Evicel Fibrin Sealant (Human) to prevent CSF leakage using a 2.0-cm durotomy mongrel dog repair model and to compare the tissue response with Tisseel (a fibrin sealant) and Duraseal (a synthetic polyethylene glycol [PEG] hydrogel sealant). METHODS: The canine durotomy repair model was used. This well-characterized model assesses the ability of sealants to achieve intraoperative watertight seals of the dura mater, as well as long-term safety and efficacy. This study included 27 mongrel dogs and had a 28-day duration. RESULTS: The 3 sealants were 100% effective in preventing CSF leakage intraoperatively at 15 mm Hg. The 2 fibrin sealants were 100% effective in postoperative sealing; the PEG hydrogel was not. Microscopically, the tissue changes induced by Evicel at the durotomy site were similar in nature except for foamy macrophages seen only with the PEG hydrogel. The extent and severity of adhesions at 28 days were less with the fibrin sealants than with the PEG hydrogel. CONCLUSION: Evicel, a fibrin sealant, was safe and effective in achieving and maintaining a watertight seal of the dura. The performance of the fibrin sealants was similar to that of the synthetic PEG hydrogel sealant with the exception of a Duraseal seal, which leaked.

Hemostatic effectiveness of Fibrin pad after partial nephrectomy in swine.

BACKGROUND: Current management of severe surgical or traumatic bleeding is often achieved by manual tamponade or occlusion using devices such as tourniquets or ligatures. There are some clinical scenarios where these options are either marginally effective or impractical. The present study evaluates a new combination device (Fibrin pad) consisting of biologically active components (human thrombin and fibrinogen) delivered to the targeted site by an absorbable synthetic matrix (oxidized regenerated cellulose and polyglactin 910) in a swine severe bleeding model. In this model, severe bleeding can be managed by concurrent use of several currently available treatments, or a more convenient option that offers performance and safety advantages. MATERIALS AND METHODS: Partial nephrectomies were performed on swine and treated with either Fibrin pad (FP) or conventional therapy (CTR)-temporary occlusion of renal artery, electrocautery, SURGIFLO, EVITHROM, SURGICEL NU-KNIT, and PDS II suture). After intraoperative hemostasis was confirmed, the animals were closed and recovered, then survived for 2, 14, or 56 d. RESULTS: Hemostasis was achieved at surgery and maintained in all FP and CTR treated animals. FP was as effective as CTR at establishing durable hemostasis. Treatment with FP did not require temporary occlusion of the renal artery and decreased the total treatment time by half. No animals in either group had complications related to postoperative bleeding at any time during the study. There was no evidence of pulmonary thrombi or evidence of thrombotic complications. No biologically significant adverse local tissue response was present in association with the Fibrin pad at any study interval, and no biologically relevant or consistent changes in blood parameters were identified. CONCLUSIONS: Fibrin pad was as effective as CTR for the primary management of severe bleeding without occlusion of the renal artery and a shorter surgical time. No evidence of a systemic or local adverse response was identified due to exposure to the Fibrin pad.