Cyclodextrin Complexation as a Way of Increasing the Aqueous Solubility and Stability of Carvedilol

Rapid Study on Mefloquine Hydrochloride Complexation with Hydroxypropyl-β-Cyclodextrin and Randomly Methylated β-Cyclodextrin: Phase Diagrams, Nuclear Magnetic Resonance Analysis, and Stability Assessment

This study investigates the complexation of mefloquine hydrochloride by cyclodextrins to improve its solubility in order to design an oral solution. This approach may enhance the effectiveness of mefloquine, a drug which can be used for malaria prophylaxis and treatment in children. Mefloquine hydrochloride's solubility was assessed in different buffer solutions, and its quantification was achieved through high-performance liquid chromatography. The complexation efficiency with cyclodextrins was evaluated, and nuclear magnetic resonance (NMR) methods were employed to determine the interactions between mefloquine and cyclodextrins. Mefloquine's solubility increased when combined with hydroxypropyl-β-cyclodextrin (HP-β-CD) and randomly methylated β-cyclodextrin (RAMEB), with RAMEB being more effective. The drug's solubility varied across different pH buffers, being higher in acidic buffers. Interestingly, mefloquine's solubility decreased with a citrate buffer, possibly due to precipitation. The NMR studies highlighted non-covalent interactions between RAMEB, HP-β-CD, and mefloquine, explaining the solubilizing effect via complexation phenomena. Furthermore, the NMR experiments indicated the complexation of mefloquine by all the studied cyclodextrins, forming diastereoisomeric complexes. Cyclodextrin complexation improved mefloquine's solubility, potentially impacting its bioavailability.

Development of a Carvedilol Oral Liquid Formulation for Paediatric Use

Carvedilol (CARV) is an 'off-label' β-blocker drug to treat cardiovascular diseases in children. Since CARV is nearly insoluble in water, only CARV solid forms are commercialized. Usually, CARV tablets are manipulated to prepare an extemporaneous liquid formulation for children in hospitals. We studied CARV to improve its aqueous solubility and develop an oral solution. In this study, we assessed the solubility and preliminary stability of CARV in different pH media. Using malic acid as a solubility enhancer had satisfactory results. We studied the chemical, physical, and microbiological stability of 1 mg/mL CARV-malic acid solution. A design of experiment (DoE) was used to optimize the CARV solution's preparation parameters. A 1 mg/mL CARV solution containing malic acid was stable for up to 12 months at 25 °C and 30 °C and 6 months at 40 °C. An equation associating malic acid with CARV concentrations was obtained using DoE. Microbiological data showed that the use of methylparaben was not necessary for this period of time. We successfully developed an aqueous CARV solution suitable for paediatrics and proven to be stable over a 12-month period.

Stability of Oral Liquid Dosage Forms in Pediatric Cardiology: A Prerequisite for Patient's Safety-A Narrative Review

The development of safe and effective pediatric formulations is essential, especially in therapeutic areas such as pediatric cardiology, where the treatment requires multiple dosing or outpatient care. Although liquid oral dosage forms are considered the formulation of choice given the dose flexibility and acceptability, the compounding practices are not endorsed by the health authorities, and achieving stability can be problematic. The purpose of this study is to provide a comprehensive overview of the stability of liquid oral dosage forms used in pediatric cardiology. An extensive review of the literature has been performed, with a particular focus on cardiovascular pharmacotherapy, by consulting the current studies indexed in PubMed, ScienceDirect, PLoS One, and Google Scholar databases. Regulations and guidelines have been considered against the studies found in the literature. Overall, the stability study is well-designed, and the critical quality attributes (CQAs) have been selected for testing. Several approaches have been identified as innovative in order to optimize stability, but opportunities to improve have been also identified, such as in-use studies and achieving dose standardization. Consequently, the information gathering and the results of the studies can be translated into clinical practice in order to achieve the desired stability of liquid oral dosage forms.

Supersaturation maintenance of carvedilol and chlorthalidone by cyclodextrin derivatives: Pronounced crystallization inhibition ability of methylated cyclodextrin

Cyclodextrin (CD) is used to solubilize poorly water-soluble drugs by inclusion complex formation. In this study, we investigated the effect of CD derivatives on stabilizing the supersaturation by inhibiting the crystallization of two poorly water-soluble drugs, carvedilol (CVD) and chlorthalidone (CLT). The phase solubility test showed that β-CD and γ-CD derivatives enhanced the solubility of CVD to a greater extent, whereas the solubility of CLT was enhanced more by β-CD derivatives. The solubilization efficacy of CD derivatives was dependent on the size fitness between the drug molecule and the CD cavity. In the drug crystallization induction time measurement, the same initial drug supersaturation ratio (S) was employed in all the CD solutions, and the methylated CD derivatives greatly outperformed unmethylated CD derivatives in stabilizing the supersaturation of both CVD and CLT. The crystallization inhibition strength of CD derivatives was strongly affected by the CD derivative substituent. Moreover, the calculated logarithm of octanol/water partition coefficients (log P) of CD derivatives showed a good correlation with drug crystallization inhibition ability. Thus, the high hydrophobicity of methylated CD plays an essential role in inhibiting crystallization. These findings can provide a valuable guide for selecting appropriate stabilizing agents for drug-supersaturation formulations.

Enhanced Efficacy of Carvedilol by Utilization of Solid Dispersion and Other Novel Strategies: A Review

Carvedilol is classified as a second class drug of Biopharmaceutical classification system (BCS), and it is an excellent beta blocker and vasodilating agent. It is used in a diverse range of disease states. Despite having tremendous advantages, the drug cannot be used effectively and productively due to aquaphobicity and poor bioavailability. To overcome this limitation, numerous novel approaches and tactics have been introduced over the past few years, such as Selfmicro emulsifying drug delivery systems (SMEDDS), nanoparticles, solid dispersions and liposomal drug delivery. The present review aims to accentuate the role of solid dispersion in improving the dissolution profile and aqua solubility of carvedilol and also to emphasize other novel formulations of carvedilol proposed to prevail the limitations of carvedilol. Solid dispersion and other novel approaches were found to play a significant role in overcoming the drawbacks of carvedilol, among which solid dispersion is the most feasible and effective approach being used worldwide. Reduced particle size, more wettability, and large surface area are obtained by the implementation of solid dispersion technique, hence improving carvedilol solubility and bioavailability.