Medical devices

Tentamus Pharma & Med’s labo­ra­to­ries conduct chem­ical and instru­mental tests in order to analyse raw mate­rials, semi-finished goods and finished batches of medical devices. We perform qual­i­ta­tive and quan­ti­ta­tive limit and content deter­mi­na­tion for a wide variety of substances such as residual solvents, heavy metals and endo­toxins. We detect cont­a­m­i­na­tion with foreign matter and verify the sterility of medical devices.

Our instru­mental analytics methods

• Atomic absorp­tion spec­trom­etry (AAS) using the following tech­niques: flame, nitrous oxide, graphite furnace, hydride and the corre­sponding diges­tion methods: acid diges­tion and microwave diges­tion to detect metals
• Induc­tively coupled plasma mass spec­trom­etry (ICP-MS) for trace analysis of heavy metals such as mercury, lead or cadmium
• Gas chro­matog­raphy (GC) with the following detec­tors: FID, NPD and MSD, e.g. deter­mi­na­tion of content and purity of phar­ma­ceu­tical raw mate­rials and finished prod­ucts, residual solvents, fatty acid composition

At Tentamus Pharma & Med, we use cell culture-based in vitro tech­niques when carrying out func­tional bioas­says or effector cell assays in order to test and certify the biocom­pat­i­bility of medical devices (DIN EN ISO 10993). This allows us to examine devices for factors such as cyto­tox­i­city as well as skin irri­ta­tion and sensi­ti­sa­tion in various cell culture models.

Func­tional bioassays

• Tests for in vitro cyto­tox­i­city (ISO 10993 – 5)
• Tests for skin irri­ta­tion (ISO 10993 – 10/OECD 439)
• Tests for skin sensi­ti­sa­tion (ISO 10993 – 10 / OECD 442 d/​e
• Tests for ocular irritation/​corrosion (OECD 460)
• Tests for ocular irri­ta­tion (OECD 492)
• Tests for skin corro­sion (OECD 431)
• Effector cell assays using various cell lines (cyto­tox­i­city, apop­tosis, ADCC, CDC)
• Proliferation/​reporter gene assays
• In vitro potency assays

Our micro­bi­o­log­ical depart­ment specialises in detecting microor­gan­isms such as aerobic and anaer­obic bacteria, bacte­rial viruses (bacte­rio­phages) as well as yeasts and moulds. We use clas­sical micro­bi­o­log­ical methods of enrich­ment, isola­tion and iden­ti­fi­ca­tion of specific microor­gan­isms to examine the sterility of raw mate­rials, inter­me­diate prod­ucts and ready-to-use batches of medical devices.

We carry out clin­ical assays for the following purposes:

• Deter­mi­na­tion of bioburden (Ph. Eur. 2.6.12, ISO 11737 – 1)
• Detec­tion of specific bacteria (Ph. Eur. 2.6.13)
• Pyrogen deter­mi­na­tion: bacte­rial endo­toxin test (Ph. Eur. 2.6.14) and mono­cyte acti­va­tion test (Ph. Eur. 2.6.30)
• Micro­bi­o­log­ical testing of cosmetics in accor­dance with CTFA or ISO standards

Our methods for biocom­pat­i­bility testing of medical devices are vali­dated in accor­dance with DIN EN ISO 10993. We avoid animal exper­i­ments and have adopted the 3Rs prin­ciple (replace­ment, reduc­tion, refine­ment). Our tests are conducted in vitro. We use cell cultures to examine factors such as cyto­tox­i­city as well as skin irri­ta­tion and sensi­ti­sa­tion in accor­dance with the revised EU MDR and DIN ISO 10993.

Our analyt­ical proce­dures for testing biocompatibility:

In vitro deter­mi­na­tion of cytotoxicity

• DIN ISO 10993 – 5/USP <87>
• Read out: XTT/​neutral red/​MTT/​MTS
• Toxi­city of diffusing substances through agar diffu­sion (USP <87>)
• Deter­mi­na­tion of photo­tox­i­city (OECD TG 432)

In vitro irri­ta­tion and sensitisation

• Skin irri­ta­tion on recon­structed human epidermis: ISO 10993 – 10 / 23 (draft) / OECD TG 439
• ARE-Nrf2 Luciferase test method (Kerati­noSens assay): OECD TG 442^d
• Human cell line acti­va­tion test (h‑CLAT): OECD TG 442^e
• In vitro skin corro­sion: OECD TG 431

In vitro corro­sion and irri­ta­tion on ocular tissue

• Recon­structed human Cornea-like Epithe­lium Test (RhCe): OECD TG 492
• Ocular Corro­sives and Severe Irri­tants: OECD TG 460

Geno­tox­i­city

• Bacte­rial reverse muta­tion test (AMES test):DIN ISO 10993 – 3/OECD TG 471
• In vitro mammalian micronu­cleus test: DIN ISO 10993 – 3/OECD TG 487

Haemo­com­pat­i­bility

• DIN ISO 10993 – 4
• Static or dynamic process using human whole blood in a closed loop system
• Integrity of red blood cells: haemol­ysis and deter­mi­na­tion of total and plasma haemoglobin
• Cellular compo­nents of blood/​blood count
• Effects on coag­u­la­tion: throm­bo­cyte count, human platelet factor 4 (hPF‑4), prothrombin (PT), fibrinogen (Fib), thrombin time (TT), throm­bin/anti-thrombin complex (TAT)
• Acti­va­tion of the immune system: comple­ment factors C3a, C5a, Sc5b‑9

Deter­mi­na­tion of bacte­rial endo­toxins and pyrogens

• Bacte­rial endo­toxin testing (BET): limulus amoe­bo­cyte lysate (LAL) test: Ph. Eur. 2.6.14: veri­fi­ca­tion and testing
• Deter­mi­na­tion of non-endo­toxin pyro­gens (NEPs): mono­cyte acti­va­tion test (MAT): Ph. Eur. 2.6.30: veri­fi­ca­tion and testing

Bioburden and sterility

• Deter­mi­na­tion of bioburden: ISO 11737 – 1, Ph. Eur 2.6.12: veri­fi­ca­tion and testing
• Sterility testing of medical devices as part of a ster­il­i­sa­tion process: ISO 11737 – 2: veri­fi­ca­tion and testing

Gener­a­tion of extracts from and chem­ical char­ac­ter­i­sa­tion of medical devices

• Gener­a­tion of extracts for biolog­ical and chem­ical char­ac­ter­i­sa­tion (DIN ISO 10993 – 12)
• Chem­ical char­ac­ter­i­sa­tion of test samples using LC-MS, GC-MS, HS-GC-MS and ICP-MS (DIN ISO 10993−13÷−18)
• Detec­tion of ethylene oxide residues (DIN ISO 10993 – 7)

In vivo testing

In addi­tion to our in vitro testing plat­form, we offer in vivo testing by qual­i­fied partner laboratories:

• ISO 10993 – 2 – Animal welfare requirements
• ISO 10993 – 6 – Tests for local effects after implantation
• ISO 10993 – 10 – Tests for irri­ta­tion and skin sensitisation
• ISO 10993 – 11 – Tests for systemic toxicity
• ISO 10993 – 20 – Prin­ci­ples and methods for immuno­tox­i­cology testing of medical devices