Solid-state compatibility screening of excipients suitable for development of indapamide sustained release solid-dosage formulation

Development, optimization and pharmacokinetic evaluation of biphasic extended-release osmotic drug delivery system of trospium chloride for promising application in treatment of overactive bladder

Background

The research was aimed with an approach to formulate biphasic extended-release system of trospium chloride resulting in controlled release of drug up to 24 h with prospects of better control on urinary frequency, efficacy, tolerability, and improved patient compliance. The push–pull osmotic pump (PPOP) bi-layered tablet of trospium chloride (60 mg) was developed with the use of immediate-release polymers in the pull layer (30 mg drug) and polyethylene oxide in the push layer (remaining 30 mg drug). The tablet was formulated by compression after non-aqueous granulation, seal coating, and semipermeable coating. The tablet prepared was laser drilled to create an orifice for drug release.

Results

Comparative in vitro dissolution and in vivo pharmacokinetic analysis of available marketed formulations demonstrated the complete drug release within 16–18 h; hence the developed biphasic extended-release system has its great importance as it provides zero-order release up to 24 h.

Conclusions

The developed biphasic extended-release drug delivery system of trospium chloride provides the drug release for 24 h with effective plasma concentration in comparison with the available marketed formulation. Extended release of drug from the developed formulation provides scope for its promising application in the treatment of overactive bladder (OAB).

Update on compatibility assessment of empagliflozin with the selected pharmaceutical excipients employed in solid dosage forms by thermal, spectroscopic and chromatographic techniques

Empagliflozin (EGF) received USFDA approval in 2014 for oral use to control the glucose levels in adults with type 2 diabetes mellitus. Albeit, a systematic drug-excipient compatibility study of EGF has not been reported in the open literature. As physical and chemical interactions affect the performance of the formulation, this study intended to unveil the drug and excipients interactions which would later help in development of a robust solid dosage form. Differential scanning calorimetry (DSC) was applied as a screening tool for the assessment of compatibility between EGF and the list of excipients mentioned in the EMEA summary of product characteristics (SmPC)-section 6.1, along with mannitol and polyvinylpyrrolidone. Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Powder Diffraction (PXRD) and Hot Stage Microscopy (HSM) methods were utilized to appraise the interpretation of DSC results adequately. Isothermal stress testing (IST) studies of EGF were performed using the selected excipients to check the presence of interaction products (IPs) and the drug content by HPLC. Additional peaks were observed in the EGF-macrogol mixture than the drug peak in the HPLC analysis after two and half months, and those were separated and identified by the Ultra-High Performance Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry (UHPLC-QTOF-MS). Overall, EGF had shown compatibility with 13 selected excipients; however, initial observation of DSC and IST studies indicated plausible interaction of the EGF with macrogol.

Development and experimental design of a novel controlled-release matrix tablet formulation for indapamide hemihydrate

CONTEXT

Development, experimental design and in vitro in vivo correlation (IVIVC) of controlled-release matrix formulation.

OBJECTIVE

Development of novel oral controlled delivery system for indapamide hemihydrate, optimization of the formulation by experimental design and evaluation regarding IVIVC on a pilot scale batch as a confirmation of a well-established formulation.

MATERIALS AND METHODS

In vitro dissolution profiles of controlled-release tablets of indapamide hemihydrate from four different matrices had been evaluated in comparison to the originator's product Natrilix (Servier) as a direction for further development and optimization of a hydroxyethylcellulose-based matrix controlled-release formulation. A central composite factorial design had been applied for the optimization of a chosen controlled-release tablet formulation.

RESULTS

The controlled-release tablets with appropriate physical and technological properties had been obtained with a matrix: binder concentration variations in the range: 20-40w/w% for the matrix and 1-3w/w% for the binder. The experimental design had defined the design space for the formulation and was prerequisite for extraction of a particular formulation that would be a subject for transfer on pilot scale and IVIV correlation.

CONCLUSIONS

The release model of the optimized formulation has shown best fit to the zero order kinetics depicted with the Hixson-Crowell erosion-dependent mechanism of release. Level A correlation was obtained.

Solid-state stability and compatibility studies of clavulanate potassium

The kinetic and thermodynamic parameters of degradation of clavulanate potassium in the solid state were studied by using a reversed phase high performance liquid chromatography (RP-HPLC) method. The degradation of clavulanate potassium was a first-order reaction depending on the substrate concentration at an increased relative air humidity (RH) and in dry air. The dependence ln k = f(1/T) became the ln k = (0.026 ± 166.35)-(2702.82 ± 1779.43)(1/T) in dry air and ln k = (1.65 ± 100.40) × 10(3)-(5748.81 ± 3659.67)(1/T) at 76.4% RH. The thermodynamic parameters Ea, ΔH(≠a), ΔS(≠a) of the degradation of clavulanate potassium in the solid state were calculated. The dependence ln k = f (RH%) assumed the form ln k = (8.78 ± 5.75) 10 (-2) (RH%) + (2.64 × 10(-8 )± 40.41). The compatibility of clavulanate potassium with commonly used excipients was studied at an increased temperature and in dry air. The geometric structure of molecule, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) orbitals were also determined in order to predict the structural changes and reactive sites in clavulanate potassium during degradation and compatibility studies in the solid state. The ultraviolet (UV), Fourier transform infrared spectroscopy (FT-IR) and Raman spectra of degraded samples of the compound were analyzed.