Bioequivalence and in vitro antimicrobial activity between generic and brand-name levofloxacin

Effects of the pharmaceutical formulation of topical medications on corneal epithelial healing after phototherapeutic keratectomy

PURPOSE

To determine the effect of the formulation of topical medications on the healing of corneal epithelial cells after phototherapeutic keratectomy (PTK).

STUDY DESIGN

Retrospective cohort study.

METHODS

We studied 271 eyes of 189 consecutive patients (aged 67.6 ± 11.8 years) who had undergone PTK for granular corneal dystrophy (n = 140), band keratopathy (n = 47), or lattice corneal dystrophy (n = 2). Postoperatively, generic or brand-named levofloxacin, 0.1% betamethasone, or 0.1% bromfenac sodium hydrate was applied topically. Patients were examined on postoperative days 1, 2, and 5 and weekly thereafter. The time to re-epithelialization was assessed by use of Kaplan-Meier and Cox proportional hazards analyses.

RESULTS

The time to re-epithelialization was significantly longer with generic 0.5% levofloxacin, at 8.2 ± 3.5 days, than with 0.5% Cravit (levofloxacin), at 6.7 ± 3.5 days (P = 0.018), or with 1.5% Cravit, at 6.3 ± 2.6 days (P = 0.000). In addition, the time to re-epithelialization was significantly longer with generic 0.1% betamethasone (Sanbetason), at 7.3 ± 3.4 days, than with brand-name 0.1% betamethasone (Rinderon), at 6.1 ± 2.5 days (P = 0.0002). The Cox proportional hazards model indicated that the use of generic formulations for levofloxacin eye drops and 0.1% betamethasone was a significant factor that delayed corneal re-epithelialization (hazard ratio [HR] = 0.72, P = 0.002 and HR = 0.77, P = 0.006, after adjustment for age). Re-epithelialization was significantly shorter in band keratopathy than in corneal dystrophy (HR = 1.56, P = 0.004). No other factors, including age, bandage contact lens, and diabetes mellitus, were significantly associated with time to re-epithelialization.

CONCLUSION

Corneal epithelial healing can be significantly affected by different antibacterial or steroid eye drops. Clinicians need to be aware that a generic formulation may affect corneal epithelial healing.

In Vitro Antimicrobial Activity of Various Cefoperazone/Sulbactam Products

: This study aims to assess the in vitro activity of different samples of cefoperazone/sulbactam (CFP/SUL) against multidrug-resistant organisms (MDROs). Clinical isolates of extended-spectrum β-lactamase (ESBL)-Escherichia coli, ESBL-Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii (CR-AB), and carbapenem-resistant Pseudomonas aeruginosa (CR-PA) were collected. The minimum inhibitory concentration (MIC) and time-killing methods were used to assess and compare the in vitro activities of different samples of cefoperazone/sulbactam (CFP/SUL) against these MDROs. For ESBL-E. coli, ESBL-K. pneumoniae, and CR-PA, product C had smaller variations than product A and B (p < 0.05). For CR-AB, product B had the largest variation compared to the other two products (p < 0.05). In the time-killing studies, significant differences among the products when used at 16/16 µg/mL were noted for ESBL-E. coli, ESBL-K. pneumoniae, and CR-AB isolates. In conclusion, this study demonstrated the significantly different activity of different products of CFP/SUL against MDROs.

Levofloxacin: Insights Into Antibiotic Resistance and Product Quality

Counterfeit and substandard medicines are recognized as one of serious threats to public health. The product quality of antibacterial medicine will compromise patients’ recovery and increase the chance of antibacterial resistance. The review aims to provide a summary of low quality levofloxacin issues and the risk factors as well as suggesting the aspects of product quality that need to be regulated strictly. Quality of the active ingredient, levofloxacin, has an important role to contribute to successful therapy. The poor quality of raw material, directly and indirectly, causes treatment failure as the presence of insufficient dose, mislabeled content, and poor dissolution characteristics can lead to lower bioavailability. Identifying and reporting these factors can potentially help in improving the quality of drug marketed in various developing countries and may also reduce the incidences of treatment failure. Dissolution test is used for testing the dissolution profiles and the rate of drug release from solid formulation such as oral formulations, thus providing information regarding the in vivo performance of a formulation and its bioequivalence. On the other hand, quality-testing procedures are used for comparing the quality of products.