ARTICLE | doi:10.20944/preprints202203.0292.v1
Subject: Chemistry, Analytical Chemistry Keywords: paracetamol; ibuprofen; caffeine; classical least-square; simultaneous; spectroscopy
Online: 22 March 2022 (03:26:27 CET)
In this paper, the classical least square (CLS) method with molecular absorption spectrophotometric measurement was used to determine simultaneously of paracetamol (PAR), ibuprofen (IBU), and caffeine (CAF) in tablets. The absorbance spectra of the standard solutions and samples were measured over a wavelength from 220 to 300 nm with a 0.5 nm step. The concentration of PAR, IBU and CAF in the sample solutions were calculated by using a program called CLS-Excel written in Microsoft Excel 2016 and Visual Basic for Applications (VBA). The method and CLS-Excel program were tested on mixed standard laboratory samples with different PAR, IBU, and CAF concentration ratios, and they showed small errors and satisfying repeatability. An analytical procedure for tablets containing PAR, IBU, and CAF was developed. The reliability of the procedure was proved via the recovery and repeatability of the analysis results with an actual tablet sample and comparing the mean contents of active substances in the tablets obtained from the analytical procedure with the from the HPLC method. The procedure is simple with a reduced cost compared with the HPLC standard method.
ARTICLE | doi:10.20944/preprints202011.0194.v1
Subject: Chemistry, Analytical Chemistry Keywords: hydrogel; e-beam cross-linking; swelling; ibuprofen; network parameters
Online: 4 November 2020 (12:41:17 CET)
We report on the successful preparation of wet dressings hydrogels based on Chitosan-Poly(N-Vinyl-Pyrrolidone)-Poly(ethylene glycol)-Poly(acrylic acid) and Poly(ethylene oxide) by e-beam cross-linking in weakly acidic media, to be used for rapid healing and pain release of infected skin wounds. The structure and compositions of hydrogels investigated according to sol-gel and swelling studies, network parameters, as well as FTIR and XPS analyses showed the efficient interaction of the hydrogel components upon irradiation, maintaining the bonding environment while the cross-linking degree increasing with the irradiation dose and the formation of a structure with the mesh size in the range 11-67 nm. Hydrogels with gel fraction above 85% and the best-swelling properties in different pH solutions were obtained for hydrogels produced with 15 kGy. The hydrogels are stable in the simulated physiological condition of an infected wound and show appropriate moisture retention capability and the water vapor transmission rate up to 272.67 g m-2 day-1, to ensure fast healing. The hydrogels proved to have a significant loading capacity of ibuprofen (IBU), being able to incorporate a therapeutic dose for the treatment of severe pains. Simultaneously, IBU was released up to 25% in the first 2h, having a release maximum after 8h.
ARTICLE | doi:10.20944/preprints202110.0138.v1
Subject: Materials Science, Nanotechnology Keywords: α- Fe2O3; hematite; gelatin; f-127; hexagonal-flake; adsorption; ibuprofen
Online: 8 October 2021 (11:17:24 CEST)
Hematite (-Fe2O3) with uniform hexagonal flakes morphology has been successfully synthesized using a combination of gelatin as natural template with F127 via hydrothermal method. The resulting hematite was investigated as adsorbent and photocatalyst for removal of ibuprofen as pharmaceutical waste. Hexagonal flake-like hematite was obtained following calcination at 500 oC with the average size was measured at 1-3 µm. Increasing the calcination temperature to 700 oC transformed the uniform hexagonal structure into cubic shape morphology. Hematite also showed high thermal stability with increasing the calcination temperatures, however, the surface area was reduced from 47 m2/g to 9 m2/g. FTIR analysis further confirmed the formation Fe-O-Fe bonds, and the main constituent elements of Fe and O were observed in EDX analysis for all samples. Fe2O3-G samples have an average adsorption capacity of 55-25.5 mg/g at 12-22% of removal efficiency when used as adsorbent for ibuprofen. The adsorption capacity was reduced with increasing the calcination temperatures due to the reduction of available surface area of the hexagonal flakes when transformed into cube. Photocatalytic degradation of ibuprofen using hematite flakes achieved 50% of removal efficiency meanwhile combination of adsorption and photocatalytic degradation further removed 80% of ibuprofen in water/hexane mixtures.
ARTICLE | doi:10.20944/preprints202011.0631.v1
Subject: Medicine & Pharmacology, Allergology Keywords: tension-type headache; migraine; neck and shoulder pain; ibuprofen; caffeine
Online: 25 November 2020 (10:51:30 CET)
As neck and/or shoulder pain (NSP) frequently occur together with tension-type headache (TTH) and migraine, we explored how concomitant NSP affects perceived treatment responses to an analgesic. An anonymous survey was performed among 895 TTH and migraine sufferers who used the analgesic 400 mg ibuprofen/100 mg caffeine. NSP was relatively abundant among patients (42.4% for TTH; 39.2% for migraine), and associated with >1 additional day with headache per month. Reported pain reduction was independent from NSP for TTH and migraine. More patients became pain-free at 2 h in migraine with NSP (42.9%) compared to migraine without NSP (32.2%), which is different from TTH with NSP (60.6%) and TTH without NSP (71.4%). For both, migraine and TTH, a recurrence of headache on the same day was more prevalent in those with concomitant NSP leading to a greater likelihood of taking a second dose of the analgesic. NSP frequently occurs together with TTH and migraine patients. In migraine, NSP seems to be associated with a better treatment response at 2 h. The more frequent recurrence of pain in those with concomitant NSP indicates that NSP makes both headache types worse. Further studies are needed to substantiate these effects.