Browsing by study line "Farmaceutisk teknologi"

Microcrystalline cellulose (MCC) is a purified, partially depolymerized cellulose, which is obtained by treating α-cellulose with mineral acids. Ever since the first microcrystalline cellulose was commercialized, different grades of microcrystalline cellulose have widely been used in the manufacture of solid dosage forms, such as tablets. MCC obtained from different sources will exhibit different physico-chemical properties, including moisture content, degree of polymerization, crystallinity, and particle morphology. In wet granulation, microcrystalline cellulose can be used as a filler, binder, and disintegrant. Recently, Aalto University has introduced a novel microcrystalline cellulose obtained from renewable raw materials by an integrated process, which has a short retention time, low energy and chemical consumption. However, very few studies have evaluated the use of AaltoCellTM as an excipient in solid dosage forms. The objective of this study was to evaluate the filler properties of three grades of AaltoCellTM to prepare paracetamol tablets with 50% (w/w) drug load and compare AaltoCellTM with a commercial microcrystalline cellulose, Vivapur 101. Due to the poor flowability of paracetamol and the experimental microcrystalline celluloses, it is challenging to direct compress tablets from paracetamol and microcrystalline mixtures. Thus, the powder mixtures were granulated by high-shear wet granulation method to improve the flowability. After the granulation, the formulations were characterized for particle size distribution, morphology and powder flow. Carr’s index Hausner ratio and angle of repose were calculated to evaluate the flowability of the formulations. In addition, an image-based analysis of powder flow was performed. A rotary tablet press equipped with single punches of 9 mm diameter was used to compress tablets. To evaluate the quality of tablets, European Pharmacopoeia tests of friability, disintegration, uniformity of mass, uniformity of content and dissolution were conducted. The AaltoCellTM A and Vivapur 101 formulations had the smallest particle size, whereas the AaltoCellTM B had the largest particle size. According to Carr’s index and Hausner ratio, the flowability of AaltoCellTM powders and Vivapur 101 varied from poor to very, very poor. After the granulation, the flowability of AaltoCellTM B and AaltoCellTM C were classified as good, while AaltoCellTM A and Vivapur 101 formulations had fair flowability. However, the results were conflicting with the flowability index values obtained in the image-based analysis. According to the results, the AaltoCellTM tablets complied with all criteria of European Pharmacopoeia and were comparable with Vivapur 101 tablets. The average tablet weight deviated ± 3.2% from the target weight. The variations in weight and drug content were small, as indicated by low RSD values. The disintegration time of the AaltoCellTM tablets was between 1-8.5 minutes. In addition, the AaltoCellTM tablets had fast dissolution with 78-84% of paracetamol released within 1 minute. Overall, AaltoCellTM is a promising excipient for use as a filler in tablets. In further studies, characterizing the powder properties, such as morphology, surface properties and hygroscopicity, would provide a better understanding of the properties of AaltoCellTM.

Drug-induced liver injury (DILI) is a relatively rare hepatic condition that can be classified as predictable and unpredictable. However, DILI is a primary reason for drug withdrawals, post-marketing warnings, and restrictions of use. DILI is a problem for the drug users but also for the pharmaceutical industry and regulatory bodies. From the perspective of patients' and clinicians', DILI is the major cause of acute liver injury. At present, a major problem predicting DILI in drug discovery is a poor understanding of its mechanisms as well as the complexity of DILI pathogenicity. The main mechanism behind DILI are alterations in bile acid homeostasis, oxidative stress, and mitochondrial dysfunction. More than 50 % of drugs causing DILI are causing mitochondrial impairment. If the normal function of mitochondria is disturbed, the energy production of the cell decreases, and cell function decline leading eventually to the cell death. In this study prediction of mitochondrial toxicity was studied using cryopreserved primary hepatocytes of humans and rats. The aim of the study was to clarify if there are interspecies differences in the prediction of toxicity but also investigate possible differences in the mechanisms behind hepatotoxicity by using three well-known compounds toxic to mitochondria. To determine these differences, total cellular ATP was measured after 2- and 24- hour exposure time to gain information on overall viability and possible adaptive responses. Mitochondrial energy pathways were studied as a real-time monitoring acute exposure of test compounds. Morphology, location, and possible adaptive response of mitochondria were studied using a fluorescent probe and antibody staining combined with high content imaging (HCI). Overall, primary rat hepatocytes were more sensitive to the test compounds than human hepatocytes. Also, there were differences between human hepatocyte batches that may reflect the metabolic differences between hepatocyte donors. Immunolabeling did not bring any additional values compared to the fluorescent probe staining in the study of morphology of mitochondria. Additionally, it was noticed that treatment with paraformaldehyde significantly changed the hepatocyte mitochondria morphology. Overall, more effort is needed to develop image analysis of mitochondria morphology. Finally, studying mitochondrial morphology has proven to be difficult, and this study did not unfortunately reveal any information about the adaptive responses of mitochondria for drug-induced liver injury.

Lääkeaineiden niukkaliukoisuus on yhä enemmän esiintyvä ongelma lääketeollisuudessa. Erityisesti BCS ryhmän II lääkeaineet ovat potentiaalisia liukoisuusominaisuuksia parantaville menetelmille. Tässä työssä näistä menetelmistä keskitytään nanokiteen, ko-kiteen ja ko-amorfisen systeemin muodostukseen ja lääkeaineena käytetään inodmetasiinia (BCS ryhmä II). Kyseisillä menetelmillä on onnistuttu parantamaan indometasiinin liukoisuusominaisuuksia, mutta vertailevia tutkimuksia ei ole aiemmin tehty. Nanokide valmistettiin märkäjauhamalla käyttäen poloksameeri 188 -stabilisaattoria. Ko-kiteen valmistuksessa käytettiin liuottimen haihdutus -menetelmää ja ko-muodostajana sakariinia. Ko-amorfisten systeemien ko-muodostajina käytettiin l-tryptofaania ja sitruunahappoa ja valmistus toteutettiin kuulamyllyllä jauhamalla. Karakterisointimenetelmillä (DLS, DSC ja XRPD) oli mahdollista todentaa nanokiteillä ja ko-kiteillä halutut ominaisuudet (partikkelikoko ja kiderakenne). Ko-amorfinen systeemi ei työssä käytetyllä menetelmällä saavuttanut amorfista rakennetta kummallakaan ko-muodostajalla. Vaikka jauhe osittain muuttui kellertäväksi (viitaten amorfiseen indometasiiniin) olivat XRPD:n ja DSC:n tulokset kiteiselle aineelle tyypillisiä. Nanokiteellä ja ko-kiteellä saavutettiin puhdasta indometasiinia parempi ominaisliukenemisnopeus sekä liukenemisnopeus jauheesta lapamenetelmällä. Systeemien välisessä vertailussa huomattiin, että nanokiteellä oli parempi liukenemisnopeus molemmissa kokeissa. Ero on selkeämmin nähtävissä lapamenetelmässä: pieni partikkelikoko mahdollistaa suuren suhteellisen pinta-alan liukenemista varten. Systeemien fysikaalista stabiilisuutta tutkittiin yhdeksän kuukauden ajan suljetussa muoviastiassa laboratorio-olosuhteissa (huoneenlämpö ja normaali ilmankosteus). Kummassakaan systeemissä ei ollut nähtävissä kiderakenteen muutoksia. Nanokiteillä oli havaittavissa lievää partikkelikoon kasvua, mikä on selitettävissä ennen koetta tehdyn sekoituksen tehottomuudella

Poorly water soluble active pharmaceutical ingredients cause problems for the drug development. Solid state modification offers one approach to overcome the issue. In this study, co-amorphous systems and co-crystals were prepared with indomethacin at molar ratio of 1:1 using nicotinamide as a co-former. Co-amorphous systems were prepared by two different preparation methods: melting the physical mixture and then quench cooling it with liquid nitrogen and dry milling with a ball mill. Co-crystals were prepared by liquid-assisted ball milling. After that, the properties, dissolution, and physical stability of the formed formulations were investigated and compared. The characterisation methods were differential scanning calorimetry, X-ray powder diffraction, Fourier-transform infrared spectroscopy, polarised light microscope and scanning electron microscope. In addition, the solubility and physical stability of the formulations were investigated. Co-amorphous systems were successfully prepared by quench cooling the melt and co-crystals by liquid-assisted ball milling. Dry milling did not induce the formation of co-amorphous systems. In the intrinsic dissolution test, both the co-amorphous system and co-crystal enhanced the dissolution of crystalline indomethacin. When examining the dissolution rate with the paddle apparatus, it was observed that the co-crystal had the highest dissolution rate among both powder and tablet samples. The co-amorphous powder sample floated on the surface of dissolution medium which impeded the dissolution of indomethacin. However, co-amorphous tablet sample showed a higher dissolution rate than crystalline indomethacin. Stability testing (25 °C, 18 %RH) showed that the co-amorphous system recrystallised into a co-crystal after two weeks of storage, while the co-crystal was found to stay stable the whole study period.