Combinatorial Approach of Thermosensitive Hydrogels and Solid Microneedles to Improve Transdermal Delivery of Valsartan: an In Vivo Proof of Concept Study

Due to the limitations of oral administration of valsartan, in this study, we aimed to develop thermosensitive hydrogel for sustained transdermal delivery and improved bioavailability of valsartan, which was further improved using solid microneedles. The thermosensitive gel formula was made using Poloxamer 407 and Poloxamer 188 in various ratios. Valsartan thermosensitive gels were evaluated for their gelation temperature, pH values, drug content, spreadability, viscosity, rheological properties, in vitro drug release, in vitro permeation, and ex vivo permeation. Finally, in vivo study was conducted, compared to oral administration. The results presented the formulations showed required characteristic for transdermal administration with desired thermosensitive properties. Based on the permeation test with and without microneedles, it was found that the use of microneedles could affect the permeation of valsartan. Specifically, the increase of microneedles' needle length also increased valsartan permeation. The combination with the highest permeation was produced by 1.55 mm MNs with the amount of drug permeated of 2.27 ± 0.01 mg. Importantly, the transdermal delivery of valsartan using this combination approach could significantly improve the bioavailability of valsartan in in vivo study. The concentration of poloxamer was able to affect the properties of the hydrogels, and the use of solid microneedles improved the transdermal delivery of valsartan. In vivo studies showed the improvement of the bioavailability of valsartan compared to oral administration, showing the effectiveness of this combination approach.

A validated LC-MS/MS method for the quantitation of cefazolin in human adipose tissue: Application of EMR-Lipid sorbent as an efficient sample clean-up before mass spectrometric analyses

A novel, simple, rapid, and sensitive high-performance liquid chromatography-tandem mass spectrometry method was developed to determine cefazolin concentrations in human adipose tissue. Sample preparation was performed by protein precipitation followed by using Captiva EMR-Lipid plates. The mobile phase consisted of 5 mM ammonium formate and 0.1% formic acid in water and 0.1% formic acid in ACN, and was pumped through a Synergi Fusion-RP column with a gradient elution program at a flow rate of 0.3 mL/min. The mass spectrometer was operated in a positive ion mode. Cloxacillin was used as an internal standard due to the observed cross-signal contribution between cefazolin and ¹³C₂,¹⁵N-cefazolin. The method was validated according to the FDA and EMA guidelines and passed all the acceptance criteria. The calibration range was 0.05-50 µg/mL in adipose tissue homogenate (0.15-150 µg/g in adipose tissue), precision CV < 4.5%, accuracy within 93.1-100.4%. The carry-over was negligible, recovery of the method was high, and no significant matrix effect was present. Rat subcutaneous adipose tissue was demonstrated to be a suitable surrogate matrix for human adipose tissue. The validated method was successfully applied in a pilot pharmacokinetic study and will further be used in a large cohort of non-obese and obese patients dosed prophylactically with cefazolin before surgeries.

Biodegradable polyelectrolyte complexes of chitosan and partially crosslinked dextran phosphate with potential for biomedical applications

Polyelectrolyte complexes (PECs) are spontaneously formed by mixing oppositely charged polyelectrolyte solutions without the use of organic solvents and chemical crosslinkers are great candidate carriers for drug delivery. Herein, biodegradable antimicrobial polyelectrolyte complexes of chitosan - dextran phosphate (DPCS) containing cefazolin were developed and characterized in order to assess their suitability for biomedical applications. For this purpose, the simultaneous partial crosslinking and functionalization of dextran with phosphoric acid in a urea melt under reduced pressure were studied. The functional group content and molecular weight of dextran phosphate were varied in order to establish their influence on gel fraction yield, thermal properties and morphologies of the hydrogels. The stoichiometric PECs of DPCS showed good in vitro biocompatibility, pH sensitivity and biodegradability depending on the hydrogel composition. The release of drug from cefazolin-loaded DPCS hydrogels was through non-Fickian diffusion and displayed long sustained-release time. The drug-loaded hydrogels showed antimicrobial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. The tunable degradation behavior under physiological conditions in combination with biocompatibility of the pristine DPCS and high antibacterial efficacy drug-loaded hydrogels may render the presented materials interesting for biomedical applications.

Quantitative analysis of cefazolin sodium in lyophilized powder by infrared spectrophotometry: Green, low cost, fast and effective

Cefazolin sodium is a broad-spectrum antibiotic used in the treatment of infectious diseases in humans and in the surgical prophylaxis. Thus, since a considerable number of people have access to this drug, it is of great interest of quality control. The aim of this study was development and validation of a green method by Fourier-Transform Infrared (FT-IR) transmission spectrophotometry for the quantification of cefazolin sodium in lyophilized powder. This technique is widely used in the pharmaceutical industry due to its ease of execution, low cost, safety and high precision and accuracy. It has been employed in the quality control routine of numerous pharmaceuticals in order to identify them and quantify their active principles. The proposed method was completely validated according ICH guidelines, showing selectivity, accuracy, precision, robustness and linearity. It was linear over the concentration range of 0.4-1.7 mg with correlation coefficient 0.999, limits of detection and quantification of 0.017 mg and 0.052 mg, respectively, precise, accurate and robust when changes in the time, pressure and mark of potassium bromide were carried out during the preparation of the pellets. The proposed method was successfully applied to the qualitative and quantitative quality control of cefazolin sodium in lyophilized powder. In addition, the method is considered green, clean and sustainable since it uses only a single reagent; it is a fast, low-cost and environmentally friendly method.

Review for Analytical Methods for the Determination of Sodium Cephalothin

Infections are the second leading cause of global morbidity and mortality, therefore it is highly important to study the antimicrobial agents such as cephalosporins. Cephalothin, an antimicrobial agent that belongs to the class of cephalosporins, has bactericidal activity and it is widely used in the Brazilian health system. In literature, some analytical methods are found for the identification and quantification of this drug, which are essential for its quality control, which ensures maintaining the product characteristics, therapeutic efficacy and patient's safety. The aim of this article is to review the available information on analytical methods for cephalothin. Thus, this study presents a literature review on cephalothin and the analytical methods developed for the analysis of this drug in official and scientific papers. It is essential to note that most of the developed methods used toxic and hazardous solvents, which makes necessary industries and researchers choose to develop environmental-friendly techniques, which will contribute to the harmonization of science, human, and environmental health.