STABILITY INDICATING HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR ESTIMATION OF ADAPALENE IN TABLET FORMULATION

Determination of Asenapine Maleate in Pharmaceutical and Biological Matrices: A Critical Review of Analytical Techniques over the Past Decade

Asenapine maleate is a second-generation atypical antipsychotic agent used in the treatment of schizophrenia, a neuropsychiatric disorder. It is available as a fast-dissolving sublingual tablet to avoid extensive first-pass metabolism with higher bioavailability as compared to oral formulations. Although, the established therapeutic solutions do not sufficiently satisfy the patient's safety and efficacy needs. Thus, the core research emphasis is to investigate strategies to produce novel formulations with enhanced safety and efficacy. This necessitates the development of robust, precise, and accurate methods for quantification of asenapine maleate in different sample matrices. Given the foregoing information, the current analysis concentrates on the different analytical techniques used to assess asenapine maleate in bulk, pharmaceutical formulations, and biological specimens. Reverse-phase HPLC coupled with UV detection is a majorly (nearly 50% of papers investigated) used technique for the estimation of asenapine maleate in formulations. On the other hand, for its quantification in the biological matrix, hyphenated techniques using mass spectrometry are widely used. This critical review reveals different analytical methodologies, including spectrophotometric, chromatographic, capillary electrophoresis techniques reported from 2011 to 2020, for the measurement of asenapine maleate in various sample matrices. The information presented in this review would be useful in future research for robust analytical method development for asenapine maleate utilizing a more scientific and risk-based approach. Also, it would aid to minimize analytical failure as well as method fine-tuning throughout the product life cycle. Further, this review may also direct scientists toward the development of methodologies for green research.

Determination of trace fluoroquinolones in water solutions and in medicinal preparations by conventional and synchronous fluorescence spectrometry

Simple, rapid and sensitive and synchronous fluorescence spectrometry (SFS) were developed for determination the fluoroquinolones of ciprofloxacin (CIP), norfloxacin (NOR) and enrofloxacin (ENR) separately in water solutions and in medicinal preparations. The optimized wavelength intervals between the emission and excitation wavelengths were 170 nm, 160 nm and 170 nm for CIP, NOR and ENR, respectively. The different experimental parameters affecting the synchronous fluorescence intensities of the three fluoroquinolones were carefully studied. Under the optimal conditions, good linearity was obtained over the range of 0.01 to 1.20 mg/L, 0.005 to 0.45 mg/L and 0.005 to 0.60 mg/L for the CIP, NOR and ENR, and with good relative standard deviations below 1.9% (n=9). In addition, the detection limits for CIP, NOR and ENR were 0.17 μg/L, 0.013 μg/L and 0.055 μg/L, respectively. What is more, compared with the conventional fluorescence spectrometry, the SFS could detect lower concentrations of each fluoroquinolone. Moreover, the proposed SFS were validated and successfully applied for the quantitative assay of each fluoroquinolone in medicinal preparations.

Determination of adapalene in gel formulation by conventional and derivative synchronous fluorimetric approaches. Application to stability studies and in vitro diffusion test

Background

Adapalene is a retinoid analogue with actions similar to those of tretinoin. It is used in topical treatment of mild to moderate acne. A survey of the literature reveals that no spectrofluorimetric method has been reported yet for determination of ADP, so it was thought necessary to develop a highly sensitive stability indicating spectrofluorimetric method.

Results

Two highly sensitive spectrofluorimetric approaches were conducted for the assay of adapalene (ADP) in its gel. In the first approach, ADP exhibits an intense native fluorescence at 389 nm after excitation at 312 nm using borate buffer (pH 7.0)/ethanol system. This approach was successfully applied for routine analysis of ADP in its gel and ideally suited to the in vitro diffusion test. To elucidate the inherent stability of ADP, bulk sample was subjected to different stress conditions as specified by ICH guidelines. The acidic and oxidative degradation products were resolved from the intact drug using second and first derivative synchronous fluorimetry at 346 and 312.45 nm, respectively (the second approach). The synchronous fluorescence was scanned at Δ λ of 80 nm in case of acidic degradation and at Δ λ of 100 nm in case of oxidative degradation. Good linearity was obtained for ADP over the range 2.0–14.0 ng/mL with good correlation coefficient   0.999 in each approach. The approaches were carefully examined in terms of linearity, accuracy and precision. They were suitable for routine quality control laboratory. Moreover, the stability-indicating power of the second approach was ascertained via forced degradation studies.

Conclusions

The proposed approaches were validated and successfully applied for the quantitative assay of a small concentration of ADP in its pharmaceutical gel. The conventional spectrofluorimetry was ideally suited for in vitro diffusion test. Stability studies were also conducted using different forced degradation condition according to ICH recommendation.Graphical abstract