scholarly journals Insulin Solution Stability and Biocompatibility with Materials Used for an Implantable Insulin Delivery Device Using Reverse Phase HPLC Methods

2019 ◽  
Vol 9 (22) ◽  
pp. 4794 ◽  
Author(s):  
Dolly Jacob ◽  
M. Joan Taylor ◽  
Paul Tomlins ◽  
Tarsem Sahota
Keyword(s):  
Stainless Steel ◽  
High Performance ◽  
Artificial Pancreas ◽  
Insulin Delivery ◽  
Chemical Degradation ◽  
Solution Stability ◽  
Delivery Device ◽  
Protective Capacity ◽  
Reverse Phase ◽  
Insulin Stability

Insulin (Humulin® R IU500) has been delivered from an implantable artificial pancreas in diabetic rats and pigs. The artificial pancreas which was implanted in the peritoneum was fabricated from several biocompatible materials such as polycarbonate, stainless steel, polyurethane, titanium and a polyurethane resin. The device also contains a glucose responsive smart gel which controls the diffusion of insulin dependent on the surrounding glucose environment. As the insulin reservoir is refillable and in contact with the device materials, assessing its biocompatibility with these various device component materials was conducted. Insulin can undergo chemical degradation mainly via a deamidation reaction on glutamine and asparagine residues rendering its biological hormone functionality. Two Reverse Phase High Performance Liquid Chromatography (RP-HPLC) methods were developed and validated for detection of insulin and degradant Asn A21 desamido insulin (method A) and insulin and degradant Asn B3 desamido insulin (method B). Material biocompatibility studies show that stainless steel and titanium are suitable for an implantable insulin delivery device design over a 31-day period. The use of polycarbonate and polyurethane could be considered if the insulin reservoir in the device was only to remain in the device for less than 11 days after which time there is a loss in cresol which acts in a protective capacity for insulin stability.

Preparation and Characterization of NH2-Terminal Fibrinogen Bβ Fragments from N-DSK of Human Fibrinogen

1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield
Keyword(s):  
High Performance ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Human Fibrinogen ◽  
Human Volunteers ◽  
Cnbr Cleavage ◽  
Two Peaks

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.

OUTOKUMPU TYPE 630

Alloy Digest ◽  
2016 ◽  
Vol 65 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
High Performance ◽  
High Strength ◽  
Heat Treating ◽  
304 Stainless Steel ◽  
Type 304 ◽  
Type 304 Stainless Steel

Abstract Outokumpu Type 630 is a martensitic age hardenable alloy of composition 17Cr-4Ni. The alloy has high strength and corrosion resistance similar to that of Type 304 stainless steel. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-1238. Producer or source: Outokumpu High Performance Stainless.

Development and Validation of a Novel Reversed Phase High Performance Liquid Chromatography with Refractive Index Detector Method for Assay of Polyvinyl Alcohol in an Ophthalmic Solution

2020 ◽  
Vol 16 (7) ◽  
pp. 867-871
Author(s):  
Harun Ergen ◽  
Muge Guleli ◽  
Cigdem Sener ◽  
Cem Caliskan ◽  
Sercan Semiz ◽  
...  
Keyword(s):  
Refractive Index ◽  
Liquid Chromatography ◽  
Polyvinyl Alcohol ◽  
High Performance ◽  
Ophthalmic Solution ◽  
Reversed Phase ◽  
Hplc Method ◽  
Solution Stability ◽  
Technical Requirements ◽  
Refractive Index Detector

Introduction: Polyvinyl alcohol (PVA), a polymer, is in demand due to its usage in different applications such as pharmaceutical, biomedical and textile, paper, food industries. Methods: A new sensitive reversed phased high-pressure liquid chromatography (RP-HPLC) method with refractive index detector (RID) was developed for determination of PVA in an ophthalmic solution containing dexpanthenol and PVA as active substances and it was validated according to The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guideline. Results: Chromatographic separation was achieved on a Chiral-AGP (150 mm × 4.0 mm, 5 μm) column kept at 30°C with an isocratic flow at a flow rate of 1.0 ml/min. The detector temperature was 30°C, the retention time of PVA was around 1.0 min and the total run time was 5 minutes. Conclusion: The proposed method showed linearity, accuracy, precision, specificity, robustness, solution stability, and system suitability results within the acceptance criteria.

Optimum HPLC Conditions for Determination of Dibucaine HCL, Fluocortolone Pivalate and Fluocortolone Caproate by Using Experimental Design

2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç
Keyword(s):  
Experimental Design ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Acid Mixture ◽  
Solution Stability ◽  
Uv Detector

Introduction:This paper presents the development and validation of a novel, fast, sensitive and accurate high performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical preparations.Experiment:Development of the chromatographic method was based on an experimental design approach. A five-level-three-factor central composite design requiring 20 experiments in this optimization study was performed in order to evaluate the effects of three independent variances including mobile phase ratio, flow rate and amount of acid in the mobile phase.Conclusion:The optimum composition for mobile phase was found as a methanol:water:acetic acid mixture at 71.6 : 26.4 : 2 (v/v/v) ratio and optimum separation was acquired by isocratic elution with a flow rate of 1.3 mL/min. The analytes were detected using a UV detector at 240 nm. The developed method was validated in terms of linearity, precision, accuracy, limit of detection/quantitation and solution stability and successfully applied to the determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical topical formulations such as suppositories and ointments.

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