Syringe siliconization process investigation and optimization.

The interior barrel of the prefilled syringe is often lubricated/siliconized by the syringe supplier or at the syringe filling site. Syringe siliconization is a complex process demanding automation with a high degree of precision; this information is often deemed "know-how" and is rarely published. The purpose of this study is to give a detailed account of developing and optimizing a bench-top siliconization unit with nozzle diving capabilities. This unit comprises a liquid dispense pump unit and a nozzle integrated with a Robo-cylinder linear actuator. The amount of coated silicone was determined by weighing the syringe before and after siliconization, and silicone distribution was visually inspected by glass powder coating or characterized by glide force testing. Nozzle spray range, nozzle retraction speed, silicone-coated amount, and air-to-nozzle pressure were found to be the key parameters affecting silicone distribution uniformity. Distribution uniformity is particularly sensitive to low-target silicone amount where the lack of silicone coating on the barrel near the needle side often caused the syringes to fail the glide force test or stall when using an autoinjector. In this bench-top unit we identified optimum coating conditions for a low silicone dose, which were also applicable to a pilot-scale siliconization system. The pilot unit outperformed the bench-top unit in a tighter control (standard deviation) in coated silicone amount due to the elimination of tubing flex. Tubing flex caused random nozzle mis-sprays and was prominent in the bench-top unit, while the inherent design of the pilot system substantially limited tubing flux. In summary, this bench-top coating unit demonstrated successful siliconization of the 1 mL long syringe with ∼0.2 mg of silicone oil using a spraying cycle also applicable to larger-scale siliconization. LAY ABSTRACT: Syringe siliconization can be considered a well-established manufacturing process and has been implemented by numerous syringe providers. However, its technical details and associated critical process parameters are rarely published. The purpose of this study is three-fold: (1) to reveal design details of a bench-top siliconization unit, (2) to identify critical process parameters and determine their optimum range to provide consistent and even silicone coating, and (3) to demonstrate the applicability of the optimum process condition derived from the bench-top unit to a pilot siliconization unit. The outcomes of this study will benefit scientists and engineers developing pre-filled syringe products by helping them to better understanding silicone spray coating principles and their relationship to siliconization processes in a large-scale manufacturing setting.

A new roadmap for biopharmaceutical drug product development: Integrating development, validation, and quality by design.

Quality by design (QbD) is a science- and risk-based approach to drug product development. Although pharmaceutical companies have historically used many of the same principles during development, this knowledge was not always formally captured or proactively submitted to regulators. In recent years, the US Food and Drug Administration has also recognized the need for more controls in the drug manufacturing processes, especially for biological therapeutics, and it has recently launched an initiative for Pharmaceutical Quality for the 21st Century to modernize pharmaceutical manufacturing and improve product quality. In the biopharmaceutical world, the QbD efforts have been mainly focused on active pharmaceutical ingredient processes with little emphasis on drug product development. We present a systematic approach to biopharmaceutical drug product development using a monoclonal antibody as an example. The approach presented herein leverages scientific understanding of products and processes, risk assessments, and rational experimental design to deliver processes that are consistent with QbD philosophy without excessive incremental effort. Data generated using these approaches will not only strengthen data packages to support specifications and manufacturing ranges but hopefully simplify implementation of postapproval changes. We anticipate that this approach will positively impact cost for companies, regulatory agencies, and patients, alike.

Spectroscopic evaluation of the stabilization of humanized monoclonal antibodies in amino acid formulations.

The protective effects of amino acids on stabilizing protein secondary structure were evaluated using diffuse reflectance FTIR spectroscopy, and interactions between proteins and arginine were detected using solid-state NMR spectroscopy. Upon freeze-drying, excipient-free anti-CD11a and anti-IgE antibodies underwent significant changes in their secondary structures. For both antibodies, the amount of intermolecular beta-sheet substantially increased and the native conformation of intramolecular beta-sheet content decreased considerably. The addition of amino acids to the formulations reduced protein secondary structure alterations in a concentration-dependent manner. Histidine and arginine appeared to be the most protective excipients (of the amino acids studied) in inhibiting protein secondary structural changes. Solid-state NMR illustrated that non-covalent interactions (e.g., hydrogen bonding, ion-dipole interactions) were formed between the arginine side chain and the protein. Glycine is the least effective additive of those studied in preventing secondary structure changes upon freeze-drying. Despite secondary structural changes, freeze-dried protein in the presence and absence of amino acids refolded back into its native conformation upon reconstitution in water.

Calorimetric investigation of protein/amino acid interactions in the solid state.

Possible protein/amino acid interactions and the physical states of amino acids after freeze-drying have been studied using isoperibol calorimetry and differential scanning calorimetry (DSC). Good linear correlations (R(2) = 0.99) between the enthalpies of solution and the percentage of antibody in all physical mixtures, as well as unchanging melting temperatures of amino acids for physical mixtures demonstrated that there is no interaction between the antibodies and amino acids studied upon physical mixing. On the other hand, positive deviations for antibody/histidine and antibody/arginine freeze-dried samples obtained from the isoperibol calorimetry results demonstrated that molecular level interactions, such as ion-dipole or electrostatic interactions or hydrogen bonding, occur between antibodies and histidine or arginine. The values of DeltaH(interaction) for antibody/histidine (1:1, w/w) and antibody/arginine (1:1, w/w) lyophilized samples were approximately 8 kJ/mol. These interactions were also confirmed by decreased and/or the disappearance of melting temperatures of the amino acids with DSC measurements. A negative deviation from linearity was detected for antibody/aspartic acid lyophilized samples which indicated partial amorphization of aspartic acid. No deviation from linearity as well as similar melting temperatures of antibody/glycine lyophilized samples indicated the absence of interactions between the antibodies and glycine upon freeze-drying.

Raman spectroscopic characterization of drying-induced structural changes in a therapeutic antibody: correlating structural changes with long-term stability.

We characterized the secondary structure of a therapeutic recombinant humanized monoclonal antibody (rhuMAb), formulated with different concentrations of sucrose, trehalose, and histidine and in solution, lyophilized, and spray-dried states. Quantitative secondary structure estimates were obtained using amide I band Raman spectroscopy and a previously developed spectral deconvolution procedure. On lyophilization or spray drying in the absence of sugar, the antibody underwent significant structural perturbation. The beta-sheet content decreased with corresponding gain in the turn and unordered content. With increasing amount of sucrose or trehalose, the extent of structural perturbation decreased. Eventually, at sugar-to-protein molar ratios of > or =360, almost complete structural preservation was observed. Histidine also protected the antibody against lyophilization-induced structural changes. The extent of structural perturbation immediately after lyophilization or spray drying exhibited good correlation with the rate of aggregation for the antibody during long-term storage under accelerated conditions. The results demonstrate that amide I band Raman spectroscopy could be a quick and reliable way to screen excipients and their concentrations during lyophilized or spray dried formulation development.

Sustained delivery of human growth hormone from a novel gel system: SABER.

PURPOSE: The purpose of this study was to evaluate the release of recombinant human growth hormone (rhGH) from a novel non-polymeric sustained release system, SABER. METHODS: The SABER system consists of sucrose acetate isobutryate, a solvent and a polymeric release modifier. Spray dried formulations of zinc complexed rhGH in sodium bicarbonate containing sucrose and polysorbate 20 were homogenized with various SABER systems (10% w/v rhGH) and assessed in vitro and in vivo (rat studies). The effect of protein to sucrose ratio in the spray dried formulation and a release modifier, poly-D,L-lactic acid (PLA), in the SABER system, on the initial release was investigated along with the effect of dose volume. RESULTS: The in vitro release studies with rhGH SABER suspensions indicate that increasing the sucrose content from 2 to 5 mg/ml in the rhGH formulations increased the initial release (24 h) from 78.0% to 93.5%. When the protein formulation was held constant and 1.0% w/w PLA was added to the solvent phase, the initial release was reduced from 78.0% to less than 5.0%. The initial release in vivo after subcutaneous administration (SC) in rats (15 mg/kg rhGH) decreased with increasing PLA content (1.0% w/w PLA, Cmax = 342.8 ng/ml; 10% w/w PLA, Cmax = 35.4 ng/ml), while increased sucrose content increased both the initial release (AUC(0-2) days) and persistence (AUC(2-7) days) over the 7 days from 64.2 to 228.4 ng day/ml (total AUC). A linear dose response (rhGH serum levels) was observed after SC administration of different rhGH SABER volumes greater than 100 microl. Histological examination of the injection sites indicated a mild inflammatory response similar to that observed after injection of PLA microspheres. CONCLUSIONS: The addition of PLA reduced the initial release rate of protein release from SABER, while increasing the sucrose content of the protein formulation yielded increased rhGH persistence. These results demonstrate that the SABER delivery system allows weight-based dosing at volumes greater than 100 microl to achieve sustained release of intact rhGH in vivo for at least 7 days.