Factors affecting solubility and penetration of clarithromycin through gastric mucus

Breaking boundaries: the advancements in transdermal delivery of antibiotics

Transdermal drug delivery systems (TDDS) for antibiotics have seen significant advances in recent years that aimed to improve the efficacy and safety of these drugs. TDDS offer many advantages over other conventional delivery systems such as non-invasiveness, controlled-release pattern, avoidance of first-pass metabolism. The objective of this review is to provide an overview on the recent advances in the TDDS of different groups of antibiotics including β-lactams, tetracyclines, macrolides, and lincosamides, utilized for their effective delivery through the skin and to explore the challenges associated with this field. The majority of antibiotics do not have favorable properties for passive transdermal delivery. Thus, novel strategies have been employed to improve the delivery of antibiotics through the skin, such as the use of nanotechnology (nanoparticles, solid-lipid nanoparticles, nanoemulsions, vesicular carriers, and liposomes) or the physical enhancement techniques like microneedles and ultrasound. In conclusion, the transdermal delivery systems could be a promising method for delivering antibiotics that have the potential to improve patient outcomes and enhance the efficacy of drugs. Further research and development are still needed to explore the potential of delivering more antibiotic drugs by using various transdermal drug delivery approaches.

Kaempferia parviflora Extracellular Vesicle Loaded with Clarithromycin for the Treatment of Helicobacter pylori Infection

Purpose

Kaempferia parviflora extracellular vesicles (KPEVs) have been reported as promising nanovesicles for drug delivery. This study aimed to load clarithromycin (CLA) into KPEVs (KPEVS-CLA) and determine the physical properties, drug-releasing efficiency, gastric cell uptake, anti-H. pylori activities, and anti-inflammatory responses in comparison with free CLA and KPEVs.

Methods

The size and surface charge of KPEVs-CLA were evaluated using dynamic light scattering and visualized using a transmission electron microscope. The encapsulation efficiency (EE%), loading capacity (LC%), and drug release of KPEVs-CLA were examined using HPLC. Anti-H. pylori growth and anti-adhesion were evaluated. IL-8 gene expression, NF-κB signaling proteins, and anti-inflammatory profiles were examined using qRT-PCR, Western blotting, and Bio-Plex immunoassay, respectively. Anti-chemotaxis was then examined using a Transwell assay.

Results

KPEVs-CLA were intact and showed a negative surface charge similar to that of KPEVs. However, slightly enlarged KPEVs were observed. CLA was successfully loaded into KPEVs with EE of 93.45% ± 2.43%, LC of 9.3% ± 3.02%. CLA release in the PBS and gastric mimic buffer with Fickian diffusion (n ≤ 0.43) according to Korsmeyer-Peppas kinetic model (R2=0.98). KPEVs-CLA was localized in the gastric cells' cytoplasm and perinuclear region. Anti-H. pylori growth and anti-H. pylori adhesion of KPEVs-CLA were compared with those of free CLA with no cytotoxicity to adenocarcinoma gastric cells. KPEVs-CLA significantly reduced IL-8, G-CSF, MIP-1α, and MIP-1β levels. Moreover, KPEVs-CLA showed a superior effect over CLA in reducing G-CSF, MIP-1α, and NF-κB phosphorylation and monocyte chemotactic activities.

Conclusion

KPEVs serve as potential carriers of CLA. They exhibited a higher efficiency in inhibiting gastric cell inflammation mediated by H. pylori infection than free CLA. The establishment of KPEVs-CLA as a nanodrug delivery model for H. pylori treatment could be applied to other plant extracellular vesicles or loaded with other cancer drugs for gastric cancer treatment.

Physiologically based pharmacokinetic modeling to assess the drug-drug interactions of anaprazole with clarithromycin and amoxicillin in patients undergoing eradication therapy of H. pylori infection

OBJECTIVE

This study aimed to assess the pharmacokinetic (PK) interactions of anaprazole, clarithromycin, and amoxicillin using physiologically based pharmacokinetic (PBPK) models.

METHODS

The PBPK models for anaprazole, clarithromycin, and amoxicillin were constructed using the GastroPlus™ software (Version 9.7) based on the physicochemical data and PK parameters obtained from literature, then were optimized and validated in healthy subjects to predict the plasma concentration-time profiles of these three drugs and assess the predictive performance of each model. According to the analysis of the properties of each drug, the developed and validated models were applied to evaluate potential drug-drug interactions (DDIs) of anaprazole, clarithromycin, and amoxicillin.

RESULTS

The developed PBPK models properly described the pharmacokinetics of anaprazole, clarithromycin, and amoxicillin well, and all predicted PK parameters (Cmax,ss, AUC0-τ,ss) ratios were within 2.0-fold of the observed values. Furthermore, the application of these models to predict the anaprazole-clarithromycin and anaprazole-amoxicillin DDIs demonstrates their good performance, with the predicted DDI Cmax,ss ratios and DDI AUC0-τ,ss ratios within 1.25-fold of the observed values, and all predicted DDI Cmax,ss, and AUC0-τ,ss ratios within 2.0-fold. The simulated results show no need to adjust the dosage when co-administered with anaprazole in patients undergoing eradication therapy of H. pylori infection since the dose remained in the therapeutic range.

CONCLUSION

The whole-body PBPK models of anaprazole, clarithromycin, and amoxicillin were built and qualified, which can predict DDIs that are mediated by gastric pH change and inhibition of metabolic enzymes, providing a mechanistic understanding of the DDIs observed in the clinic of clarithromycin, amoxicillin with anaprazole.

Pharmacokinetic interaction of voriconazole and clarithromycin in Pakistani healthy male volunteers: a single dose, randomized, crossover, open-label study

Background: Voriconazole an antifungal drug, has a potential for drug-drug interactions (DDIs) with administered drugs. Clarithromycin is a Cytochromes P450 CYP (3A4 and 2C19) enzyme inhibitor, and voriconazole is a substrate and inhibitor of these two enzymes. Being a substrate of the same enzyme for metabolism and transport, the chemical nature and pKa of both interacting drugs make these drugs better candidates for potential pharmacokinetic drug-drug interactions (PK-DDIs). This study aimed to evaluate the effect of clarithromycin on the pharmacokinetic profile of voriconazole in healthy volunteers. Methods: A single oral dose, open-label, randomized, crossover study was designed for assessing PK-DDI in healthy volunteers, consisting of 2 weeks washout period. Voriconazole, either alone (2 mg × 200 mg, tablet, P/O) or along with clarithromycin (voriconazole 2 mg × 200 mg, tablet + clarithromycin 500 mg, tablet, P/O), was administered to enrolled volunteers in two sequences. The blood samples (approximately 3 cc) were collected from volunteers for up to 24 h. Plasma concentrations of voriconazole were analyzed by an isocratic, reversed-phase high-performance-liquid chromatography ultraviolet-visible detector (RP HPLC UV-Vis) and a non-compartmental method. Results: In the present study, when voriconazole was administered with clarithromycin versus administered alone, a significant increase in peak plasma concentration (Cmax) of voriconazole by 52% (geometric mean ratio GMR: 1.52; 90% CI 1.04, 1.55; p = 0.000) was observed. Similarly, the area under the curve from time zero to infinity (AUC^0-∞) and the area under the concentration-time curve from time zero to time-t (AUC^0-t) of voriconazole also significantly increased by 21% (GMR: 1.14; 90% CI 9.09, 10.02; p = 0.013), and 16% (GMR: 1.15; 90% CI 8.08, 10.02; p = 0.007), respectively. In addition, the results also showed a reduction in the apparent volume of distribution (Vd) by 23% (GMR: 0.76; 90% CI 5.00, 6.20; p = 0.051), and apparent clearance (CL) by 13% (GMR: 0.87; 90% CI 41.95, 45.73; p = 0.019) of voriconazole. Conclusion: The alterations in PK parameters of voriconazole after concomitant administration of clarithromycin are of clinical significance. Therefore, adjustments in dosage regimens are warranted. In addition, extreme caution and therapeutic drug monitoring are necessary while co-prescribing both drugs. Clinical Trial Registration: clinicalTrials.gov, Identifier NCT05380245.

The role of mucus on drug transport and its potential to affect therapeutic outcomes

A layer of mucus covers the surface of all wet epithelia throughout the human body. Mucus is a hydrogel mainly composed of water, mucins (glycoproteins), DNA, proteins, lipids, and cell debris. This complex composition yields a tenacious viscoelastic hydrogel that lubricates and protects the exposed epithelia from external threats and enzymatic degradation. The natural protective role of mucus is nowadays acknowledged as a major barrier to be overcome in non-invasive drug delivery. The heterogeneity of mucus components offers a wide range of potential chemical interaction sites for macromolecules, while the mesh-like architecture given to mucus by the intermolecular cross-linking of mucin molecules results in a dense network that physically, and in a size-dependent manner, hinders the diffusion of nanoparticles through mucus. Consequently, drug diffusion, epithelial absorption, drug bioavailability, and ultimately therapeutic outcomes of mucosal drug delivery can be attenuated.

Dissolution enhancement and in vitro performance of clarithromycin nanocrystals produced by precipitation-lyophilization-homogenization method

The gastroduodenal diseases caused by Helicobacter pylori were commonly treated with antibiotic clarithromycin as a standard regimen. According to the poorly water-soluble of clarithromycin, the nanocrystal formulation was prepared. The aim of this study was to investigate an enhancement effect of clarithromycin nanocrystals produced by precipitation-lyophilization-homogenization (PLH) method on the saturation solubility, dissolution velocity, antibiotic activity, permeability through the gastric mucus and cellular permeability. Poloxamer 407 and sodium lauryl sulfate (SLS) were chosen as combined stabilizers in the nanocrystal system. The obtained clarithromycin nanocrystals were identified as cubic particles by SEM with a bulk population of approximately 400nm existed in crystalline and/or partial amorphous form as investigated by DSC and XRPD. The saturation solubility of the clarithromycin nanocrystals was increased by 1.5- and 6-folds higher than clarithromycin powder in buffer pH 5.0 and 6.8, respectively. The dissolution profiles of clarithromycin nanocrystals at pH 5.0 and 6.8 were significantly different from clarithromycin powder and the marketed product (f1 value >15 and f2 value <50). All dissolution parameters (relative dissolution rate, percent dissolution efficiency and mean dissolution time) showed that clarithromycin nanocrystals had higher dissolution rate when compared with the clarithromycin powder, the lyophilized coarse suspension and the marketed product. The bioassay study by diffusion agar method showed a maintained antibiotic activity of clarithromycin nanocrystals solubilized in buffer solution which was greater potency than the lyophilized coarse suspension and the clarithromycin powder. Additionally, the nanocrystals possessed higher permeability through gastric mucus and cellular monolayer of Caco-2 and NCI-N87 cells as compared to the lyophilized coarse suspension and the clarithromycin powder. The results indicated that, the developed clarithromycin nanocrystals were a potential delivery system that exerts more effectiveness in H. pylori eradication.

The formulation, chemical and physical characterisation of clarithromycin-based macrolide solution pressurised metered dose inhaler

Objectives

The formulation of a clarithromycin (CLA) pressurised metered dose inhalers (pMDIs) solution formulation opens up exciting therapeutic opportunities for the treatment of inflammation in chronic obstructive lung diseases. In this study, we have formulated and tested a low dose macrolide formulation of CLA for treatment of inflammation and studied its physicochemical and aerosol properties.

Methods

The system was characterised for in-vitro aerosol performance using an Andersen cascade impactor. Short-term chemical and physical stability was assessed by dose content uniformity over a range of temperatures. Standard physicochemical characteristics were also investigated using scanning electron microscopy, thermo analysis and laser diffraction techniques.

Key findings

The formulation had a relatively high fine particle fraction (47%) and produced a particle size distribution suitable for inhalation drug delivery. Particles had an irregular morphology and were predominately amorphous. Furthermore, the short-term stability showed the formulation to be stable from 4 to 37°C.

Conclusions

This study demonstrated the feasibility of formulating a solution-based pMDI containing CLA for the treatment of lung inflammatory diseases.

Fate of paclitaxel lipid nanocapsules in intestinal mucus in view of their oral delivery

The bioavailability of paclitaxel (Ptx) has previously been improved via its encapsulation in lipid nanocapsules (LNCs). In this work, the interactions between LNCs and intestinal mucus are studied because they are viewed as an important barrier to successful oral delivery. The rheological properties of different batches of pig intestinal mucus were studied under different conditions (the effect of hydration and the presence of LNCs). Fluorescence resonance energy transfer (FRET) was used to study the stability of LNCs in mucus at 37°C for at least 3 hours. Diffusion through 223, 446, and 893 μm mucus layers of 8.4, 16.8, and 42 μg/mL Ptx formulated as Taxol® (Bristol-Myers Squibb, Rueil-Malmaison, France) or encapsulated in LNCs (Ptx-LNCs) were investigated. The effect of the size of the LNCs on their diffusion was also investigated (range, 25–110 nm in diameter). Mucus behaves as a non-Newtonian gel with rheofluidifying properties and a flow threshold. The viscous (G″) and elastic (G′) moduli and flow threshold of the two mucus batches varied with water content, but G′ remained below G″. LNCs had no effect on mucus viscosity and flow threshold. The FRET efficiency remained at 78% after 3 hours. Because the destruction of the LNCs would lead to a FRET efficiency below 25%, these results suggest only a slight modification of LNCs after their contact with mucus. The diffusion of Taxol® and Ptx-LNCs in mucus decreases if the mucus layer is thicker. Interestingly, the apparent permeability across mucus is higher for Ptx-LNCs than for Taxol® for drug concentrations of 16.8 and 42 μg/mL Ptx (P<0.05). The diffusion of Ptx-LNCs through mucus is not size-dependent. This study shows that LNCs are stable in mucus, do not change mucus rheological properties, and improve Ptx diffusion at low concentrations, thus making these systems good candidates for Ptx oral delivery. The study of the physicochemical interaction between the LNC surface and its diffusion in mucus is now envisioned.

Preoperative versus postoperative Helicobacter pylori eradication therapy in gastric cancer patients: a randomized trial

OBJECTIVES

Helicobacter pylori (H. pylori) eradication is strongly recommended for gastric cancer patients who undergo subtotal gastrectomy. The efficacy of proton pump inhibitor-based triple therapy for H. pylori eradication has not been adequately assessed in the gastric remnant. The aim of this study was to compare the efficacy of postoperative versus preoperative H. pylori eradication therapy.

METHODS

A total of 138 distal gastric cancer patients with H. pylori infection were randomized to receive either preoperative (preop, N = 68) or postoperative (postop, N = 70) proton pump inhibitor-based triple therapy for H. pylori eradication. The regimen consisted of rabeprazole 10 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily for 7 days. Eradication was assessed by rapid urease test and histology 12 wk after surgery.

RESULTS

By intention-to-treat (ITT) analysis, H. pylori eradication rates were 84.6% (95% CI 73.5-92.4) in the preop group and 83.1% (95% CI 71.7-91.2) in the postop group (P= 0.99). By per protocol (PP) analysis, the rates were 87.3% (95% CI 76.5-94.4) in the preop group and 86.9% (95% CI 75.8-94.2) in the postop group (P= 0.99). In the postop group, eradication rates did not differ with reconstruction method (Billroth I vs II, 80.4%[95% CI 66.1-90.6]vs 89.5%[95% CI 66.9-98.7] by ITT analysis (P= 0.49), and 85.7%[95% CI 71.5-94.6]vs 89.5% (95% CI 66.9-98.7) by PP analysis, P= 0.99).

CONCLUSIONS

In distal gastric cancer patients, the effect of proton pump inhibitor-based triple therapy for H. pylori eradication was not different whether given postoperatively or preoperatively.

Evaluation ofin-vitro dissolution andin-vivo absorption for two different film-coated pellets of clarithromycin

The aim of this study was to compare two formulations of film-coated pellets containing clarithromycin after single oral dose study in healthy male volunteers. Two formulations with different coating polymers were prepared: formulation-1 (F-1) was prepared by incorporating three kinds of pH-dependent gradient-release coated pellets into capsules and formulation-2 (F-2) was prepared by coated with an insoluble semiosmotic film. Release profiles of film-coated pellets were evaluated using paddle method under different conditions. Pharmacokinetic profiles of these formulations were obtained in three healthy male volunteers and compared to commercially available immediate release (IR) tablets. The relative bioavailability based on the AUC0-24h was found to be 96.2% and 58.7% for F-1 and F-2 compared with IR, and the Tmax was delayed.

The influence of excipients on the diffusion of ibuprofen and paracetamol in gastric mucus

The aim of this study was to examine the diffusion of commonly administered analgesics, ibuprofen and paracetamol, through gastric mucus. As ibuprofen and paracetamol are often formulated with alkalising excipients, or are commonly co-administered with antacids that have been demonstrated to alter their absorption, diffusion was also studied in the presence of a range of soluble and insoluble antacids or buffering agents. The effect of pH, which has been demonstrated to modify the properties of mucus, was also studied. Mucus was a significant barrier to diffusion for both drugs, compared to an unstirred aqueous layer with diffusion rates significantly lower in the presence of a mucus barrier for both drugs; ibuprofen diffusion also demonstrated a significant increase in the lag time. Paracetamol diffusion was not significantly affected by addition of any antacid, whereas ibuprofen rates were affected and the diffusion lag time for ibuprofen was significantly reduced in all cases. Isolated increases in pH increased the rate and reduced the lag time for ibuprofen diffusion. It was shown that mucus acts as a passive barrier in the case of paracetamol diffusion, and an interactive barrier to ibuprofen diffusion. Changes in mucus viscosity at different pH values may be responsible for the observed changes in ibuprofen diffusion rate.

Diagnostic methods for Helicobacter pylori detection and eradication

Helicobacter pylori is the principal cause of peptic ulcer disease and an important risk factor for the development of gastric cancer. The efficacy of 1 week triple therapies, which often have eradication rates of>90%, is undermined by poor patient compliance and bacterial antimicrobial resistance. The development of new anti-H. pylori therapies presents enormous challenges to clinical pharmacologists, not only in the identification of novel targets, but also in ensuring adequate drug delivery to the unique gastric mucus niche of H. pylori. Animal models of H. pylori infection have been developed but their clinical validity has yet to be established. Vaccination, to prevent or treat infection, has been demonstrated in animal models, but human studies have not been so encouraging.

Effects of clarithromycin and amoxicillin on gastric emptying in rats

The effects of oral administration of clarithromycin (CLR), amoxicillin (AMX), and lansoprazole (LPZ) on gastric emptying in rats were investigated by a glass powder method and a phenol red method. By both test methods, no significant effects on gastric emptying were observed when CLR, AMX, or LPZ was administered alone or when the three drugs were administered concomitantly. The levels of gastrointestinal absorption of [(14)C]CLR and [(14)C]AMX were measured. Four hours after injection of [(14)C]CLR or [(14)C]AMX into the stomach and duodenum loops of rats, 86.63 and 1.27% of the original amount of [(14)C]CLR administered were recovered in the contents of the stomach and duodenum loops, respectively, and 80.01 and 55.88% of the original amount of [(14)C]AMX administered were recovered in the contents of the stomach and duodenum loops, respectively.

Amoxicillin and ampicillin are not transferred to gastric juice irrespective of Helicobacter pylori status or acid blockade by omeprazole

BACKGROUND

The effects of proton pump inhibitors and Helicobacter pylori infection on the distribution of drugs used for the eradication of the bacteria are poorly understood.

AIM

The aim of this study was to investigate the effects of a 7-day administration of 20 mg of omeprazole on the pharmacokinetics of amoxicillin and ampicillin in the plasma, saliva and gastric juice of individuals with and without H. pylori infection.

METHODS

Fifty-four healthy volunteers without endoscopic lesions were enrolled. Twenty-six volunteers were included in the amoxicillin study and 28 individuals in the ampicillin study. Each study had an open randomized two-period crossover design and a 21-day washout period between phases. Plasma, saliva and gastric juice concentrations of amoxicillin and ampicillin in subjects with and without omeprazole pre-treatment were measured by reversed-phase HPLC using UV detection.

RESULTS

Neither pre-treatment with omeprazole nor H. pylori infection interfered with the plasma bioavailability of amoxicillin or ampicillin, as assessed by the AUC0-2 h. Neither ampicillin nor amoxicillin were detected in saliva or gastric juice in any study phase.

CONCLUSION

Short-term treatment with omeprazole does not interfere with the pharmacokinetics of amoxicillin or ampicillin. Our results also exclude the presence of a transfer mechanism for amoxicillin or ampicillin from the plasma to the gastric lumen.

Current role of acid suppressants in Helicobacter pylori eradication therapy

Helicobacter pylori induces chronic active gastritis that may progress to atrophy. Serious clinical consequences are peptic ulcer disease and gastric malignancies. Today, treatment of the infection is an appropriate option and is strongly recommended in various clinical situations. Although many antibiotics are effective against H. pylori in vitro, few substances are suitable for use in vivo. This is because H. pylori lives in a unique environment in which several factors may affect the pharmacokinetic and pharmacodynamic properties of the anti-microbial agents. One of the most important factors is gastric acidity. This article reviews the effects of acid suppression on H. pylori and the associated gastritis, the potential mechanisms by which anti-secretory drugs such as proton pump inhibitors might enhance the activity of anti-microbials in vivo, and the results of clinical trials supporting the current view that proton pump inhibitors are a mainstay in the treatment of this infection.

Review article: factors influencing antibiotic transfer across the gastric mucosa

The delivery of antimicrobial drugs to Helicobacter pylori within the stomach is poorly understood. The gastric environment represents a unique pharmacokinetic compartment, into which drug can be delivered directly following oral administration, or indirectly following intestinal absorption and transfer from the blood into the stomach across the gastric mucosa. Several methods have been used to study drug disposition across the gastric mucosa, including endoscopic biopsy studies, nasogastric intubation studies and animal models. Direct, or topical, delivery is limited by luminal drug degradation, drug formulation and the permeability of the mucus layer. Indirect, or systemic, delivery is limited by factors affecting the concentration gradient across the gastric mucosa and the permeability of the mucosa. These factors include intragastric pH, plasma protein binding, drug lipophilicity, the presence of active transport mechanisms, drugs that damage the gastric mucosa and inflammation secondary to H. pylori infection. Little is known about the last of these, and further research in this area should help in the rational approach to development of treatments against H. pylori.