Mucoadhesive microparticles as potential carriers in inhalation delivery of doxycycline hyclate:a comparative study

The present work compares and evaluates the suitability of different polymer-based microparticles for inhalation delivery of doxycycline hyclate.Mucoadhesive polymers,such as sodium carboxymethyl cellulose,sodium alginate,polyvinyl alcohol,polyvinylpyrolidone,starch,and carbopol were selected as carriers for inhalation delivery.Microparticles were prepared by spray drying and evaluated in terms of yield,moisture content,morphology,tapped density,encapsulation efficiency,in vitro mucoadhesion,thermal properties and in vitro aerosolization performance.Additionally,the cytotoxicity of the microparticles on H1299 human alveolar cell line was examined.Smooth spherical to collapsed doughnut shaped particles were formed.They exhibited tap densities of 0.202-0.502 g/cm^(3) and mass median aerodynamic diameter of 3.746.54 um.Mucoadhesion was highest in case of carbopol-based microparticles.Drug release from these microparticles exhibited biphasic Fickian type of diffusion.Only at the highest concentration of microparticles(1 mg/mL)less than 90% cell viability was seen in DX loaded sodium alginate microparticles(DXSA,87.2%),starch microparticles(DXST,85.1%)and carbopol microparticles(DXCP,82.7%)preparations after 48 h of exposure to alveolar cells.The results clearly indicate that sodium carboxymethyl cellulose-based microparticles may serve as an ideal carrier for inhalation delivery of doxycycline hyclate.

Research into Antibacterial Effects of Polysaccharide-Based Microparticles

Background: Due to worldwide increases in the prevalence of antibiotic-resistant bacteria, it is necessary to develop an active drug delivery system that can enable therapeutics to reach their molecular targets. Maintaining the concentration of any drug in the blood at a certain level for a long time is critical in the practice of drug therapy. With the increased frequency of drug use, the blood concentration of drugs exceeds the therapeutic level, leading to toxicity or ineffectiveness. To solve these problems, in recent years, much attention has been given to developing micro/nano preparations by encapsulating biologically active compounds on polymeric carriers. Therefore, we aimed to extract pectin from sea buckthorn peel, prepare microcapsules containing antibiotics, and determine their physical and chemical properties. Methods: Wastes were separated from sea buckthorn under “Medical raw materials Dry fruit of Hippophae rhamnoides MNS 5225:2002”. Pectin was isolated from sea buckthorn waste according to the “method for determination of pectins MNS3080:1981” standard. The degree of esterification was determined according to ISO 7623:2016. Antibiotic encapsulation with coacervates and water-based emulsions was performed. Antibiotic sensitivity was determined by microdilution according to the Clinical Laboratory Standard Institute (МТ100-S27) method. The results were determined between standard strains of Staphylococcus aureus ATCC 29213 and MRSA ATCC 2758 at different dilution concentrations. Result: Pectin is a brown powder with a sour taste and no odor. There was 71.4% esterification of pectin, 8.9% yield, 1.3% free carboxyl group, 3.2% methylated carboxyl group, 4.5% total carboxyl group, 3.5% ash, and 0.1% nitrogen. A study of the antibacterial activity of pectin containing doxycycline hyclate found that the inhibition of bacterial growth was 0.8 times less than that of pure pectin. It was 1 time less than that of doxycycline alone, and 33 times smaller than that of wontaxime when compared to pure pectin. Pectin containing doxycycline hyclate inhibited MRSA growth at a concentration 6 times lower than pure pectin. This was 2 times lower than doxycycline alone, and 8 times lower than wontaxime. Conclusion: Pectin yields 1.3 after 60 minutes of separation at a sediment concentration ratio of 1:1.15 and pH = 2. Pectin itself is antibacterial against MRSA.