Development and validation of ultra-performance liquid chromatography method for the determination of meloxicam and its impurities in active pharmaceutical ingredients

Determination of Meloxicam Using Direct and Indirect Flow Injection Spectrophotometry

Background:

Meloxicam is a non-steroidal anti-inflammatory drug, known to inhibit cyclooxygenase, a key enzyme of prostaglandin biosynthesis at the site of inflammation.

Objectives:

Two sensitive and fast spectrophotometric methods (direct and indirect) using flOW INJection Analysis (FIA) have been described for the assay of meloxicam in pure and in pharmaceutical formulations.

Methods:

The direct method (method A) depended on the coupling of meloxicam with diazotized procaine benzylpenicillin in alkaline medium. In contrast, the indirect method (method B) involved a charge transfer reaction between the alkaline hydrolytic product of meloxicam as n-donor with metol (p-methylaminophenol sulfate) as a π- acceptor using sodium periodate as an oxidant.

Results:

The colored products exhibited absorption maxima at 492 and 656 nm for method A and B respectively. The methods obeyed Beer’s low over concentration ranges of 5-80 and 15-225 μg/mL, respectively. The detection limits were 2.73 and 5.26 μg/mL for direct and indirect methods, respectively. The chemical and physical parameters associated with FIA manifolds were optimized to construct the most sensitive and reproducible results.

Conclusion:

Methods described herein are cheap, environmentally friendly and showed no significant difference with those of the official method indicated no significant difference in accuracy and precision.

Meloxicam quantification in rabbit plasma by RP-HPLC: optimization and application to pharmacokinetic study

Background

The goal of the proposed study was to validate a rapid, simple, an accurate, robust, and sensitive bioanalytical method for quantifying Meloxicam and Lornoxicam (as internal standard) in rabbit plasma.

Result

Limit of detection and limit of quantification for Meloxicam were found to be 0.0081 and 0.1035 μg mL−1, respectively. The bioanalysis was continued according to standard guidelines and successfully used for bioavailability studies of meloxicam after single dose administration of pure drug and the formulation in rabbit plasma. Finally, obtained results proved its simplicity and an efficiency to be applied for the therapeutic drug monitoring and bioequivalence studies.

Conclusion

Therefore, the set RP-HPLC bioanalysis is simple, convenient, and acceptable to analyze meloxicam in bulk and pharmaceutical formulations in rabbit plasma.

Graphical abstract

Study of Top-down and Bottom-up Approaches by Using Design of Experiment (DoE) to Produce Meloxicam Nanocrystal Capsules

In order to investigate the correlation among energy input-related, drug-related, and stabilizer-related aspects for both top-down and bottom-up nanocrystal production, meloxicam nanosuspensions (NS) were produced by using three different methods (low-energy wet milling, high-pressure homogenization, and precipitation) and each method was optimized by using design of experiment (DoE). Box-Behnken design of 3 factors and 3 levels was applied for the optimization of each method. All the three models were found to be significant and the optimized process parameters were used for production of NS, respectively. Interestingly, by comparison of the top-down and bottom-up approaches, the influence of energy input (homogenization pressure or milling speed) from the instruments seemed not significant for top-down compared with bottom-up for this drug. Different mechanisms of homogenization (relatively high energy zone) and milling (relatively low energy zone) led to obtained various significant correlations for each method. Capsules containing nanocrystals were successfully produced by using a novel method applying NS (after wet bead milling and homogenization processes) as wetting agent for direct capsuling and showed superiority regarding as dissolution rate compared with the traditional two-step method (freeze-dried powder used for capsuling as the first step). Different NS preparation methodologies proved to have a direct influence on the following capsuling process and consequently, in the dissolution rate. This study also proved that residual DMSO in nanosuspension after precipitation process could affect the freeze-drying process, which might further alter the redispersion and influence the downstream processes.