Meropenem (MRP) and metronidazole (MTZ) are anti-microbial agents that concomitantly administrated for the management of severe acute pancreatic patients. An innovative direct, simple, rapid, cost effective and sensitive high performance thin layer chromatographic (HPTLC) method was successfully developed for in vitro and in vivo simultaneous determination of MRP and MTZ. The developed method relied on direct spotting of plasma without any pre-treatment due to low plasma protein binding of studied drugs followed by chromatographic separation and UV detection at isoabsorptive point of both drugs (306 nm). Chromatographic separation was done by methanol: acetonitrile: water (10:10:5, v/v/v) using formic acid as pH modifier. The Rf values were 0.55 ± 0.03 and 0.84 ± 0.02 for MRP and MTZ, respectively. Under optimum conditions, a linear relationship was obtained in concentration range of 100–1000 and 10–250 ng band−1 for MRP and MTZ, respectively with good correlation coefficient 0.9994–0.9997. The detection limits were 33.13 and 3.17 ng band−1 for MRP and MTZ, respectively. The method was validated according to ICH and US-FDA guidelines. The developed method was successfully applied for in vitro and in vivo quantification of MRP and MTZ in spiked human plasma and real plasma of acute pancreatic patients, respectively. Furthermore, the method was applied for assay of individual dosage forms of both drug.

Simultaneous chromatographic determination of both ertapenem (ERP) and paracetamol (PCL) was achieved for the first time via a new HPTLC-densitometric method. The developed method relied on a simple planar chromatographic separation by mixture of acetonitrile and water (35:15, v/v) and dual-wavelength detection at λmax of both drugs (294 and 247 nm for ERP and PCL, respectively). The Rf values were 0.74 ± 0.05 and 0.88 ± 0.05 for ERP and PCL, respectively. Under the optimized conditions, the linearity range was 40.0–600.0 and 15.0–200.0 ng band−1 for ERP and PCL, respectively with good correlation coefficients (0.9997 and 0.9998 for ERP and PCL, respectively). The LOD were 13.08 and 3.65 ng band−1 for ERP and PCL, respectively. The method validation parameters were in compliance with the international standards. The developed method was enough sensitive and selective for the determination of ERP in the presence of its open beta-lactam ring degradation product, which makes it a suitable stability-indicating method. Consequently, it was successfully applied for pharmaceutical formulation, spiked and real plasma samples of healthy rabbits for real pharmacokinetic studies of ERP and PCL.

Simultaneous chromatographic determination of both ertapenem (ERP) and paracetamol (PCL) was achieved for the first time via a new HPTLC-densitometric method. The developed method relied on a simple planar chromatographic separation by mixture of acetonitrile and water (35:15, v/v) and dual-wavelength detection at λmax of both drugs (294 and 247 nm for ERP and PCL, respectively). The Rf values were 0.74 ± 0.05 and 0.88 ± 0.05 for ERP and PCL, respectively. Under the optimized conditions, the linearity range was 40.0–600.0 and 15.0–200.0 ng band−1 for ERP and PCL, respectively with good correlation coefficients (0.9997 and 0.9998 for ERP and PCL, respectively). The LOD were 13.08 and 3.65 ng band−1 for ERP and PCL, respectively. The method validation parameters were in compliance with the international standards. The developed method was enough sensitive and selective for the determination of ERP in the presence of its open beta-lactam ring degradation product, which makes it a suitable stability-indicating method. Consequently, it was successfully applied for pharmaceutical formulation, spiked and real plasma samples of healthy rabbits for real pharmacokinetic studies of ERP and PCL.

Simultaneous chromatographic determination of both ertapenem (ERP) and paracetamol (PCL) was achieved for the first time via a new HPTLC-densitometric method. The developed method relied on a simple planar chromatographic separation by mixture of acetonitrile and water (35:15, v/v) and dual-wavelength detection at λmax of both drugs (294 and 247 nm for ERP and PCL, respectively). The Rf values were 0.74 ± 0.05 and 0.88 ± 0.05 for ERP and PCL, respectively. Under the optimized conditions, the linearity range was 40.0–600.0 and 15.0–200.0 ng band−1 for ERP and PCL, respectively with good correlation coefficients (0.9997 and 0.9998 for ERP and PCL, respectively). The LOD were 13.08 and 3.65 ng band−1 for ERP and PCL, respectively. The method validation parameters were in compliance with the international standards. The developed method was enough sensitive and selective for the determination of ERP in the presence of its open beta-lactam ring degradation product, which makes it a suitable stability-indicating method. Consequently, it was successfully applied for pharmaceutical formulation, spiked and real plasma samples of healthy rabbits for real pharmacokinetic studies of ERP and PCL.

Simultaneous chromatographic determination of both ertapenem (ERP) and paracetamol (PCL) was achieved for the first time via a new HPTLC-densitometric method. The developed method relied on a simple planar chromatographic separation by mixture of acetonitrile and water (35:15, v/v) and dual-wavelength detection at λmax of both drugs (294 and 247 nm for ERP and PCL, respectively). The Rf values were 0.74 ± 0.05 and 0.88 ± 0.05 for ERP and PCL, respectively. Under the optimized conditions, the linearity range was 40.0–600.0 and 15.0–200.0 ng band−1 for ERP and PCL, respectively with good correlation coefficients (0.9997 and 0.9998 for ERP and PCL, respectively). The LOD were 13.08 and 3.65 ng band−1 for ERP and PCL, respectively. The method validation parameters were in compliance with the international standards. The developed method was enough sensitive and selective for the determination of ERP in the presence of its open beta-lactam ring degradation product, which makes it a suitable stability-indicating method. Consequently, it was successfully applied for pharmaceutical formulation, spiked and real plasma samples of healthy rabbits for real pharmacokinetic studies of ERP and PCL.

A highly sensitive, selective and precise HPTLC method coupled with fluorescence detection was developed and validated for the determination of -aminocephalosporin antibiotics; namely cefalexin, cefadroxil and cefradine in their standard solutions. The applicability of the developed methodology was demonstrated via analysis of cefalexin in goat milk samples. Full optimization of the fluorescence derivatization reaction was carried out with regard to the standard solutions of the studied compounds or after extraction of milk samples. The separation of the studied compounds was performed on HPTLC precoated silica gel plates 60 F254 using acetonitrile: water in a ratio 85:15 (v/v) as a mobile phase. The retention behavior of the formed derivatives was discussed in detail. It was found that hydrophilic interaction mode is the main interaction mechanism governing the retention of the formed derivatives. In addition, an experimental design approach was conducted for optimization of the chromatographic conditions. Modified QuEChERS was applied as an efficient extraction technique of cefalexin from both spiked and real goat milk samples. Optimization of QuEChERS extraction technique to achieve the highest extraction recovery was performed and the results indicate that this method provides a good extraction recovery(83–116%) for cefalexin from goat milk samples. Limit of detection (LOD) of the developed method was found to be 0.023, 0.005, and 0.023 ng band−1 for cefalexin, cefadroxil and cefradine, respectively in their standard solutions and 0.165 ng band−1 for cefalexin in goat milk samples. According to the achieved LOD values, the method sensitivity was quasi-equivalent to other methods based on expensive techniques such as HPLC-UV and HPLC-MS and it is sufficient to determine cefalexin below its MRL in milk samples. Moreover, the method was successfully applied to a pharmacokinetic study of cefalexin in goat milk after single intramuscular injection of 10 mg of cefalexin kg−1 per body weight.

A highly sensitive, selective and precise HPTLC method coupled with fluorescence detection was developed and validated for the determination of -aminocephalosporin antibiotics; namely cefalexin, cefadroxil and cefradine in their standard solutions. The applicability of the developed methodology was demonstrated via analysis of cefalexin in goat milk samples. Full optimization of the fluorescence derivatization reaction was carried out with regard to the standard solutions of the studied compounds or after extraction of milk samples. The separation of the studied compounds was performed on HPTLC precoated silica gel plates 60 F254 using acetonitrile: water in a ratio 85:15 (v/v) as a mobile phase. The retention behavior of the formed derivatives was discussed in detail. It was found that hydrophilic interaction mode is the main interaction mechanism governing the retention of the formed derivatives. In addition, an experimental design approach was conducted for optimization of the chromatographic conditions. Modified QuEChERS was applied as an efficient extraction technique of cefalexin from both spiked and real goat milk samples. Optimization of QuEChERS extraction technique to achieve the highest extraction recovery was performed and the results indicate that this method provides a good extraction recovery(83–116%) for cefalexin from goat milk samples. Limit of detection (LOD) of the developed method was found to be 0.023, 0.005, and 0.023 ng band−1 for cefalexin, cefadroxil and cefradine, respectively in their standard solutions and 0.165 ng band−1 for cefalexin in goat milk samples. According to the achieved LOD values, the method sensitivity was quasi-equivalent to other methods based on expensive techniques such as HPLC-UV and HPLC-MS and it is sufficient to determine cefalexin below its MRL in milk samples. Moreover, the method was successfully applied to a pharmacokinetic study of cefalexin in goat milk after single intramuscular injection of 10 mg of cefalexin kg−1 per body weight.

A highly sensitive, selective and precise HPTLC method coupled with fluorescence detection was developed and validated for the determination of -aminocephalosporin antibiotics; namely cefalexin, cefadroxil and cefradine in their standard solutions. The applicability of the developed methodology was demonstrated via analysis of cefalexin in goat milk samples. Full optimization of the fluorescence derivatization reaction was carried out with regard to the standard solutions of the studied compounds or after extraction of milk samples. The separation of the studied compounds was performed on HPTLC precoated silica gel plates 60 F254 using acetonitrile: water in a ratio 85:15 (v/v) as a mobile phase. The retention behavior of the formed derivatives was discussed in detail. It was found that hydrophilic interaction mode is the main interaction mechanism governing the retention of the formed derivatives. In addition, an experimental design approach was conducted for optimization of the chromatographic conditions. Modified QuEChERS was applied as an efficient extraction technique of cefalexin from both spiked and real goat milk samples. Optimization of QuEChERS extraction technique to achieve the highest extraction recovery was performed and the results indicate that this method provides a good extraction recovery(83–116%) for cefalexin from goat milk samples. Limit of detection (LOD) of the developed method was found to be 0.023, 0.005, and 0.023 ng band−1 for cefalexin, cefadroxil and cefradine, respectively in their standard solutions and 0.165 ng band−1 for cefalexin in goat milk samples. According to the achieved LOD values, the method sensitivity was quasi-equivalent to other methods based on expensive techniques such as HPLC-UV and HPLC-MS and it is sufficient to determine cefalexin below its MRL in milk samples. Moreover, the method was successfully applied to a pharmacokinetic study of cefalexin in goat milk after single intramuscular injection of 10 mg of cefalexin kg−1 per body weight.

A molecularly imprinted polymer (MIP) was developed for the electrochemical determination of the antiviral drug sofosbuvir (SOF). The MIP was obtained by polymerization of p-aminothiophenol (p-ATP) on N,S co-doped graphene quantum dots (N,S@GQDs) in the presence of gold nanoparticles to form gold-sulfur covalent network. The presence of quantum dots improves the electron transfer rate, enhances surface activity and amplifies the signal. The nanocomposites were characterized by FTIR, TEM, EDX, and SEM. The electrochemical performance of the electrode was investigated by differential pulse voltammetry and cyclic voltammetry. The sensor uses hexacyanoferrate as the redox probe and is best operated at a potential of around 0.36 V vs. Ag/AgCl. It has a linear response over the concentration range of 1–400 nM SOF, with a detection limit of 0.36 nM. Other features include high selectivity, good reproducibility and temporal stability. The sensor was applied to the determination of SOF in spiked human plasma.

A molecularly imprinted polymer (MIP) was developed for the electrochemical determination of the antiviral drug sofosbuvir (SOF). The MIP was obtained by polymerization of p-aminothiophenol (p-ATP) on N,S co-doped graphene quantum dots (N,S@GQDs) in the presence of gold nanoparticles to form gold-sulfur covalent network. The presence of quantum dots improves the electron transfer rate, enhances surface activity and amplifies the signal. The nanocomposites were characterized by FTIR, TEM, EDX, and SEM. The electrochemical performance of the electrode was investigated by differential pulse voltammetry and cyclic voltammetry. The sensor uses hexacyanoferrate as the redox probe and is best operated at a potential of around 0.36 V vs. Ag/AgCl. It has a linear response over the concentration range of 1–400 nM SOF, with a detection limit of 0.36 nM. Other features include high selectivity, good reproducibility and temporal stability. The sensor was applied to the determination of SOF in spiked human plasma.