Recent Advances in Dissolution Testing and Their Use to Improve In Vitro–In Vivo Correlations in Oral Drug Formulations

Environmentally sustainable DRS-FTIR probe assisted by chemometric tools for quality control analysis of cinnarizine and piracetam having diverged concentration ranges: Validation, greenness, and whiteness studies

A novel diffuse reflectance fourier transform infrared spectroscopic method accompanied by chemometrics was optimized to fulfill the white analytical chemistry and green analytical chemistry principles for the quantification of cinnarizine and piracetam for the first time without any prior separation in their challenging pharmaceutical preparation, which has a pretty substantial difference in the concentration of cinnarizine/piracetam (1:16). Furthermore, the suggested method was used for cinnarizine/piracetam dissolution testing as an effective alternative to traditional methods. For the cinnarizine/piracetam dissolution tests, we used a dissolution vessel with 900 mL of phosphate buffer pH 2.5 at 37 °C ± 0.5 °C, then the sampling was carried out by frequent withdrawal of 20 µl samples from the dissolution vessel at a one-minute interval, over one hour, then representative fourier transform infrared spectra were recorded. To create a partial-least-squares regression model, a fractional factorial design with 5 different levels and 2 factors was used. This led to the creation of 25 mixtures, 15 as a calibration set and 10 as a validation set, with varying concentration ranges: 1-75 and 16-1000 μg/mL for cinnarizine/piracetam, respectively. Upon optimization of the partial-least-squares regression model, in terms of latent variables and spectral region, root mean square error of cross-validation of 0.477 and 0.270, for cinnarizine/piracetam respectively, were obtained. The optimized partial-least-squares regression model was further validated, providing good results in terms of recovery% (around 98 to 102 %), root mean square error of prediction (0.436 and 3.329), relative root mean square error of prediction (1.210 and 1.245), bias-corrected mean square error of prediction (0.059 and 0.081), and limit of detection (0.125 and 2.786) for cinnarizine/piracetam respectively. Ultimately, the developed method was assessed for whiteness, greenness, and sustainability using five assessment tools. the developed method achieved a greener national environmental method index and complementary green analytical procedure index quadrants with higher eco-scale assessment scores (91), analytical greenness metric scores (0.87), and red-greenblue 12 algorithm scores (89.7) than the reported methods, showing high practical and environmental acceptance for quality control of cinnarizine/piracetam.

Polymeric Nanogel for Oral Delivery of the Chemotherapeutic Agent: Fabrication and Evaluation Alongside Toxicological Studies and Histopathological Examination

Nanogel has attracted considerable attention as one of the most versatile drug delivery systems, especially for site-specific and/or time-controlled delivery of the chemotherapeutic agent. The main objective of this study was to prepare the polymeric nanogel characterized by Fourier transform infrared spectroscopy, x-ray diffraction, thermogravimetric analysis, differential scanning, and oral acute toxicity. Free radical polymerization was done for the fabrication of polymeric nanogel. Fourier transform infrared spectroscopy was used to confirm the successful free radical polymerization. Various techniques such as x-ray diffraction, differential scanning calorimetric, and thermogravimetric analysis measurement were used to investigate the thermal behavior and crystallinity of developed nanogel. Parameters such as swelling, drug loading, and in vitro drug release is enhanced as polymers and monomers concentrations increase while these parameters decrease in case of increasing crosslinker concentration. The oral biocompatibility results of developed nanogel exhibited no toxicity in rabbits. Histopathological changes were observed between empty and loaded group. The nanosized gel offers a specific surface area which increases the stability of loaded drug (oxaliplatin) and bioavailability of the drug (oxaliplatin) as compared to the conventional drug delivery systems.

Superior Dissolution Behavior and Bioavailability of Pharmaceutical Cocrystals and Recent Regulatory Issues

Cocrystallization has been used extensively to optimize the physicochemical properties of active pharmaceutical ingredients (APIs), such as stability, dissolution, and bioavailability. This review summarizes the history and development of cocrystals, the differences between pharmaceutical cocrystals and salts, and the mechanism underlying the improvement of dissolution through cocrystallization. The correlation of in vitro dissolution and in vivo absorption data (IVIVC) of cocrystals has been discussed as well. Subsequently, guidelines for regulatory classification of cocrystals by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) are introduced. Finally, d-α-tocopherol is used as an example to demonstrate the potential of cocrystals in patent generation.

Fabrication of Tizanidine Loaded Patches Using Flaxseed Oil and Coriander Oil as a Penetration Enhancer for Transdermal Delivery

Transdermal drug delivery is important to maintain plasma drug concentrations for therapeutic efficacy. The current study reports the design, formulation, and evaluation of tizanidine transdermal patches formulated using chitosan and thiolated chitosan, ethyl cellulose (EC), polyvinylpyrrolidone (PVP), and Eudragit RL100 in different ratios. The tizanidine patches were formulated using flaxseed oil and coriander oil in the concentrations of 1% v/w, 2% v/w, 3% v/w, 4% v/w, 5% v/w, and 10% v/w. The patches were subjected to characterization of physicochemical property (thickness, weight uniformity, drug content, efficiency, percentage moisture uptake/loss), in vitro drug release and drug permeation, skin irritation, in vivo application, pharmacokinetics analysis, and stability studies. The results indicate that the interaction of thiolated chitosan with the negative charges of the skin opens the tight junctions of the skin, whereas flaxseed and coriander oils change the conformational domain of the skin. The novelty of this study is in the use of flaxseed and coriander oils as skin permeation enhancers for the formulation of tizanidine transdermal patches. The formulations follow non-Fickian drug release kinetics. The FTZNE23, FTZNE36 and FTZNE54, with 5% v/w flaxseed oil loaded formulations, exhibited higher flux through rabbit skin compared with FTZNE30, FTZNE35, FTZNE42, and FTZNE47, formulations loaded with 10% v/w coriander oil. The study concludes that flaxseed oil is a better choice for formulating tizanidine patches, offering optimal plasma concentration and therapeutic efficacy, and recommends the use of flaxseed and coriander oil based patches as a novel transdermal delivery system for tizanidine and related classes of drugs.