School of Pharmacy
The university of Jordan
graduated from University of Strathclyde 1998
Phd pharmaceutical analysis
Analytical Chemistry, Pharmacology, Toxicology and Pharmaceutics
Yusuf Al-Hiari, Shereen Arabiyat, Violet Kasabri, Imad Hamdan, Ihab Almasri, Mohammad Yasin, and Dalya Al-Saad The University of Jordan
Background: Cancer is one of the greatest troubling maladies currently. It is believed that it is the second reason for death following cardiovascular maladies. Owing to the multiplicity of its types, stages and genetic basis, there is no existing drug to cure all types of cancer. Resistance to present drugs and severe adverse effects are other challenges in the struggle against cancer. In such pursuit, fluoroquinolones (FQs) have the potential as antiproliferative compounds due to safety, low cost, and absence of resistance.
Aims: In this study, we aim to synthesize biologically active compounds that have dual anticancer and anti-lipase potential. Sixteen compounds were prepared, fully characterized, and studied through identification of IC50 values against the highly susceptible cancer cell lines.
Methods: In this work we are concerned with synthesizing biologically active compounds that belong to fluoroquinolones (FQs) with dual anti-colorectal cancer and anti-lipase activity, owing to association between cancer and obesity, conduct titration and docking experiments to validate our hypothesis.
Results: In vitro findings indicated that these compounds demonstrated promising anticancer activity against tested cell lines in micromolar range with a potency comparable to cisplatin. Compound 11 exhibited approximately doubled potency compared to cisplatin against SW620 colorectal cancer cell line with IC50 3.2 μM which proposes FQs as potent antiproliferative agents. The synthesized Fluoroquinolone (FQ) compounds were further screened for their in vitro anti-lipase potential. The findings demonstrated that all the screened compounds have demonstrated remarkable anti-lipase activity, as compared to control molecule orlistat. Compound 9 exhibited comparable activity to orlistat against pancreatic lipase with IC50 0.4 μM which proposes FQs as potent pancreatic lipase inhibitors.
Conclusions: The anticancer potential of these derivatives is referred to their ability to inhibit Topo II which indicates that chelation is the mechanism of inhibition of Topo II emphasized with titration and docking experiments.
Randa S. H. Mansour, Aamal Y. Al Khawaja, Imad I. Hamdan, and Enam A. Khalil Public Library of Science (PLoS)
The interaction of pharmacologically active drugs with SC biochemical components is underestimated in pharmaceutical research. The aim of this research was to illustrate that some drugs intended for transdermal delivery could interact with the protein component of SC. Such interactions could be in favor of or opposition to their percutaneous absorption. IR microspectroscopy was used to delineate possible interaction of SC keratin with three losartan salts LOS-K, LOS-DEA and LOS-AML salts in addition to AML-BES salt. The results of PCA, combined with comparisons of average second derivative spectra of SC samples treated with these salts and the control SC, showed that LOS-DEA did not interact with SC, thus providing base line permeation of losartan. AML-BES, LOS-AML and LOS-K salts modified the conformational structure of keratin. The disorganization effect on the α-helical structure and induced formation of parallel β-sheets and random coils were in the order of AML-BES˃LOS-AML˃LOS-K. The order of the impact of treatments which resulted in increased formation of β-turns was AML-BES˃LOS-AML. The formation of antiparallel β-sheets was manifested by LOS-AML. Thus, the overall effect of these salts on the SC protein was AML-BES˃LOS-AML˃LOS-K. The impact of LOS-K was associated with improved permeation whereas the impact of LOS-AML was associated with hindered permeation of both losartan and amlodipine. There is a possibility that losartan and amlodipine when present in combination inside SC, their binding to the protein is enhanced leading to being retained within SC.
Ghada Kamal, Samaa Abdullah, Fatemah Basingab, Ahmad Bani-Jaber, and Imad I. Hamdan Elsevier BV
Aamal Y. Al Khawaja, Enam A. Khalil, Randa SH. Mansour, and Imad I. Hamdan The University of Jordan
Drug molecular salt composed of the antihypertensive compound losartan (LOS) as the anion and the antihypertensive drug amlodipine (AMLO) was prepared. The prepared salt (LOS-AMLO) was characterized by measurement of purity, water content, solubility, partition coefficient, and melting behavior in addition to common spectroscopic techniques (UV, FTIR and NMR). NMR spectral shifts of particular protons of LOS in particular were quite useful in explaining the points of interaction and association between the two ionic species so that a 3D structure could be proposed. LOS-AMLO exhibited a significantly lower melting point than its parent compounds (65 oC) which places the salt within the ionic liquids category, in a broad sense of the definition. LOS-AMLO was found to have much lower solubility than LOS with a substantially higher apparent partition coefficient. The high partition coefficient together with lower melting temperature is favorable properties for the transdermal permeation of pharmaceuticals. However, diffusion studies through the human stratum corneum, from an aqueous solution based on propylene glycol revealed a vast decrease in the permeation of both drugs from the molecular (ionic liquid) salt form. Interestingly the experiment demonstrated that the salt structure might be maintained during permeation but with indications of strong chemical interaction between the salt and the constituents of the barrier.
Firas F. Awwadi, Lina A. Dahabiyeh, and Imad I. Hamdan Springer Science and Business Media LLC
Molecular salts formation is a simple and widely used approach to alter the physicochemical properties of active pharmaceutical ingredients, such as ciprofloxacin (CP), without modifying their chemical structures. In the current work, two co-crystals of p-coumaric acid (PCMA) and organic salts of CP cation (CPH) were prepared and characterized in solid state by X-ray diffraction and by NMR spectroscopy in solution. The two organic salts are CPH:benzoate anion (CPH:BA) and CPH:salicylate anion (CPH:SA). To our knowledge, these are the first two examples of co-crystals of CPH organic salt and a different organic acid. In the two co-crystals (CPH:BA:PCMA and CPH:SA:PCMA), the anion (BA or SA) connects the PCMA molecules and the CPH via O–H∙∙∙O and N–H∙∙∙O hydrogen bonding interactions. The ratio between the three crystalline species in the two co-crystals (CPH:BA:PCMA and CPH:SA:PCMA) is (1:1:1), the ratio was confirmed in solution by NMR spectroscopy. Co-Crystals of ciprofloxacinuim cation salts of salicylate or benzoate anions and p-coumaric acid have been studied in solution using NMR spectroscopy and in solid state using X-ray crystallography
Imad I. Hamdan, Dua'a G.H. Farah, Enam A. Khalil, Randa S.H. Mansour, and Heba Abdel-Halim Elsevier BV
Dua'a G. H. Faraha, E. Khalil, Randa Mansourc and I. Hamdan
Insulin detemir (ID) is a long-acting form of insulin that is characterized by the covalent attachment of a lipophilic tail of myristate, and commercially available as Levemir®. No satisfactory simple isocratic stability-indicating HPLC method has been reported for its quality control. A novel simple and isocratic reversed-phase HPLC method was developed and validated for the simultaneous determination of ID along with its dosage form additives in the available commercial preparations. The method employed C4 column (5μm, 250 × 4.6 mm), a mobile phase consisting of 50 mM phosphate buffer pH 2.7, acetonitrile, triethylamine (62:37:1) and 0.02 g/ml sodium sulfate, that was delivered isocraticaly at a flow rate of 1.5 ml/min, and detection performed at 214nm. The method was properly validated and was shown linear over the range 80–120% of the assay concentration for ID, phenol, and m-cresol. The method was also selective, specific, precise, and accurate. Furthermore, the validated method was applied to separate the major degradation products in those preparations. Forced degradation studies in different pH values, which are the first to be reported for ID, showed that the degradation products were baseline separated from ID itself and/or other formulation additives. Thus, the method has been demonstrated to be a stability-indicating assay.
Imad I. Hamdan, Dina El-Sabawi, Rula Darwish, and Lina A. Dahabiyeh Walter de Gruyter GmbH
Abstract The formation of salts is considered a simple strategy to modify the physicochemical properties of active pharmaceutical ingredients. In this study, seven novel binary and ternary organic salts of ciprofloxacin (CP) were prepared with benzoic acid (BA), acetylsalicylic acid (ASA), p-coumaric acid (PCMA) and p-aminosalicylic acid (PASA). They were characterized by spectroscopic techniques and differential scanning calorimetry. Solubility and partition coefficients values were also measured. Evaluation of the antimicrobial activity of the organic salts against Staphylococcus aureus and Staphylococcus epidermidis revealed that most of the new salts had higher antimicrobial activity than CPHCl against both strains. The most active compounds against S. epidermidis and S. aureus were CP-PASA and CPPCMA, resp., which were up to fourteen times more potent than parent CP-HCl. Our findings indicated a strong correlation between the lipophilicity of the formed salts and their antimicrobial activity and showed that an optimum value of lipophilicity (log P = 0.75) seemed to be necessary to maximize the antimicrobial activity. These findings highlighted the improved physical, thermal and antimicrobial properties of the new salts of CP that can aid in providing higher bioavailability than CP-HCl.
Randa S. H. Mansour, Imad I. Hamdan, Mutaz S. H. Salem, Enam A. Khalil, and ALSayed A. Sallam Public Library of Science (PLoS)
The focus of this research was to develop and validate a suitable HPLC method, which allows simultaneous determination of three proposed skin model penetrants to investigate the percutaneous diffusion behavior of their combination: caffeine, methyl paraben and butyl paraben. These penetrants were selected because they represent a wide range of lipophilicities. This model highlights the effect of combining penetrants of different molecular properties on their diffusion behavior through skin. The proposed method employed a gradient system that was systematically optimized for separation and quantification of the penetrants. The effect of the stationary phase (C18, C4 and cyano (CN)) was assessed with CN proven to be superior in terms of peak shape, retentivity and dynamic linear range. Significant differences in retention time, peak broadening, and quantifiability between different stationary phases could be demonstrated. The method was validated as per ICH guidelines Q2 (R1) with a satisfactory outcome. The method was successfully applied for real diffusion experiments, and revealed notable differences between the individual penetrants and their ternary mixture on transdermal permeation. The method could potentially be extended to determine these analytes in other related skin permeation investigations.
Maram Diab, Al-Sayed Sallam, Imad Hamdan, Randa Mansour, Rohanah Hussain, Giuliano Siligardi, Nidal Qinna, and Enam Khalil MDPI AG
Insulin mucoadhesive buccal films (MBF) are a noninvasive insulin delivery system that offers an advantageous alternative route of administration to subcutaneous injection. One major concern in the formulation of insulin MBF is the preservation of an insulin secondary structure in the presence of the other film components. Buccal films were formulated using chitosan, glycerin, and L-arginine. The MBF-forming solutions (MBF-FS) and the films (MBF) were examined for their chemical and structural stability and for their in vivo activity. Enzyme-Linked Immunosorbent Assay (ELISA) of the insulin-loaded MBF showed that each individualized unit dose was at least loaded with 80% of the insulin theoretical dose. Results of Synchrotron Radiation Circular Dichroism (SRCD) measurements revealed that MBF-FS retained the α-helices and β–sheets conformations of insulin. Fourier transform infrared (FTIR)-microspectroscopy (FTIR-MS) examination of insulin MBF revealed the protective action of L-arginine on insulin structure by interacting with chitosan and minimizing the formation of an unordered structure and β-strand. A blood glucose-lowering effect of insulin MBF was observed in comparison with subcutaneous (S.C) injection using a rat model. As a result; chitosan-based MBFs were formulated and characterized using SRCD and FTIR-MS techniques. Furthermore, the results of in vivo testing suggested the MBFs as a promising delivery system for insulin.
Imad I. Hamdan, Dina El-Sabawi, N.M. Tverdokhleb, A.O. Lantushenko, M.P. Evstigneev, and Rana Abu-Dahab Elsevier BV
Imad Hamdan, Dua'a Farah, and Rana Abu-Dahaba Abu-Dahab Polish Pharmaceutical Society
Metformin HCl (Mtf) is a polar compound with low bioavailability. Counter ions have been shown to improve the bioavailability of polar ionizable drugs. The goal of this work was to develop an HPLC method that is capable of separating and quantifying Mtf from a group of selected organic anions: diclofenac sodium (DS), citric acid (CA), hydroxyl cinnamic acid (HCA), 8-anilinonaphthalene-1-sulfonic acid (ANS), and trisodium phosphate (TSP). Thus, the effect of the mixture of anions on the transport of Mtf through Caco-2 cells could be studied. During the development of the method, interesting chromatographic behaviors of Mtf were observed using a polar stationary phase (HypersilÆ SAS, C1). The developed method was validated and found to be linear in the range of 2-100 μg/mL with good accuracy and precision. The method was applied for transport experiments of Mtf across Caco-2 cells in the presence and absence of organic anions. Apparent permeability coefficients (Papp) were calculated. The Papp of Mtf was increased in the presence of CA and DS from 3.37 ◊ 10 cm/s to 5.08 ◊ 10 and 4.25 ◊ 10 cm/s respectively, while it was decreased to 1.9 ◊ 10 cm/s (p-value 0.01) in the presence of HCA. Interestingly, the Papp for Mtf increased more than four-fold when present with both calcium and CA together, which might lead to significant improvement in the bioavailability of
Nagham S. Al-dmour, Rana M.N. Abu-Dahab, Maxim P. Evstigneev, Victor V. Kostjukov, Dina El-Sabawi, and Imad I. Hamdan Elsevier BV
Imad I. Hamdan, Violet N. Kasabri, Yusuf M. Al-Hiari, Dina El-Sabawi, and Hiba Zalloum Walter de Gruyter GmbH
Abstract Twenty-five structurally diverse compounds have been tested in vitro for their pancreatic lipase (PL) inhibitory activity. Despite the diversity of tested compounds, the relationship comprising structural attributes of the compounds could be established to correlate with the observed inhibitory activity. Compounds that exerted inhibitory action through surface activity were of different profile from the rest of compounds. When co-incubated with orlistat (OsT), important synergistic effects for some compounds (orphenadrine, gliclazide, cefuroxime and sulfacetamide) were revealed, while antagonistic effects were demonstrated for others (camphor sulfonic acid and dinitro salicylic acid). Docking studies for the most active molecules were performed and molecular interaction forces with the PL active site were identified. The results suggested co-binding of OsT along with the other inhibitor in the binding site in cases of synergistic effect but not in the case of antagonistic effect. These results were additionally supported by affinity capillary electrophoresis. In conclusion, synergistic lipase inhibitory activity between OsT and some other pharmaceutical compounds was demonstrated for the first time, which might help improve the pharmacological effect of OsT.
Dina El-Sabawi, Rana Abu-Dahab, Amal G. Al Bakri, and Imad I. Hamdan African Journals Online (AJOL)
Purpose: To study the interaction between ciprofloxacin hydrochloride (Cipro) and diclofenac sodium (DS) in the presence and absence of metal ions. Methods: Complexes were prepared in the aqueous phase at different molar ratios (r) of Cipro:DS (ranged from 0.2 – 2.0). The complexes were characterized by Fourier transform-infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and high pressure liquid chromatography (HPLC). Their properties, i.e., solubility, dissolution and partition coefficient (log P), were studied along with their permeability across Caco-2 cells. Furthermore, the antimicrobial activity of Cipro and its complexes was determined using standard broth dilution method and expressed as minimum inhibitory concentration (MIC). Results: Cipro formed an ion pair with DS. The product was confirmed to be a combination of the two drugs, DS and Cipro, but in a ratio that is dependent on the added amounts of each component (r = 1:1 or 1:2). The 1:1 product was more lipophilic than the individual components leading to a lower aqueous solubility and a higher octanol/water partition coefficient log P (6.7 vs. 0.77). The presence of DS within the dissolution medium appeared to modify the dissolution of Cipro depending on the concentration. Moreover, ternary complexes involving Cipro, DS and metal ions (iron and/or calcium) exhibited improved antimicrobial effect (MIC, 0.016 μg/ml compared to 0.258 μg/ml for Cipro). Caco-2 cell permeation data indicate that the presence of DS significantly improved the apparent permeability coefficient (Papp) of Cipro (20.6 × 10 -6 cm/s) which was three times higher than that of free Cipro (p < 0.05). DS also appeared to counteract the well-known negative effect of metal ions on the bioavailability of Cipro. Conclusion: There is a clinically relevant interaction between DS and Cipro at the absorption level as a result of ion pair formation, which might even counteract the negative effect of metals on the absorption of Cipro. These findings should aid the design of new Cipro ion pairs that provide higher bioavailability than free Cipro. Keywords: Ciprofloxacin, Diclofenac, Interaction, Ion pair, Permeability coefficient, Bioavailability, Absorption
Dina El-Sabawi, Rana Abu-Dahab, Waleed A. Zalloum, Fadia Ijbara, and Imad I. Hamdan Informa UK Limited
Abstract Objective: To study the potential influence of selected metal ions on absorption (and hence oral bioavailability of ciprofloxacin (Cipro) in presence and absence of a competing ligand. Significance: The presence of metal ions together with Cipro results in complexes exhibiting a decreased bioavailability. Attempts were made to better understand the mechanism of decreased Cipro bioavailability in the presence of metals such as calcium and ferrous ions, and a small-sized ligand citric acid (CitA). Methods: Effect of complex size or other potential factors was studied using diffusion through synthetic membrane, permeation studies across Caco-2 cells and capillary electrophoresis. A molecular dynamics (MD) simulation study was conducted to find the arrangement and the nature of the interactions between Cipro molecules and ferrous ions. Results: Cipro was shown to form complexes with metals and CitA. The presence of CitA improved permeation of Cipro through the synthetic membrane but this was not as obvious in case of Caco-2 cells. Capillary electrophoresis suggested the existence of large molecular aggregates of Cipro: metal complexes. MD simulations offered clear evidence of large size aggregates in line with the experimental findings. CitA alone significantly improved permeation of Cipro through Caco-2 cells. Conclusions: The size of the formed complexes, rather than the decrease in the solubility of formed complexes, plays a significant role in permeation (absorption) of Cipro. CitA might ameliorate the effect of co-administered metal ions on the bioavailability of Cipro.
Mervat Alsous, Imad Hamdan, Mohammad Saleh, James McElnay, Robert Horne, and Amira Masri Elsevier BV
Imad I. Hamdan, Dina El-Sabawi, and Rana Abu-Dahab Pleiades Publishing Ltd
A new salt of gliclazide (GZD) was prepared and was shown to have a significantly higher aqueous solubility at physiological pH together with superior dissolution profiles in comparison to GZD employing an organic amino-alcohol base. Characterization by NMR, IR, DSC, conductometry and HPLC techniques concluded that an ion pair salt is formed between acidic GZD and basic aminopropanol (AMP). In addition to the presence of about 5% tightly bound water, hydrogen bonds appeared to form extensively between GZD, AMP and water molecules. Unlike many of solubility enhancing approaches, the salt did not hamper the permeability of GZD as shown by transport through Caco-2 cells model. In vivo studies on rats confirmed that the blood glucose lowering effect of GZD-AMP was significantly higher and more rapid compared to parent GZD indicating an enhanced overall performance of the prepared salt.
Randa S.H. Mansour, Alsayed A. Sallam, Imad I. Hamdan, Enam A. Khalil, and Ibraheem Yousef Elsevier BV
Ahmad Bani-Jaber, Iyad Alshawabkeh, Samaa Abdullah, Imad Hamdan, Adel Ardakani, and Maha Habash Springer Science and Business Media LLC
Due to its unique properties, such as biodegradability, biocompatibility, high amphiphilic property, and micelle formation, casein (CS) has been increasingly studied for drug delivery. We used CS as a drug carrier in solid dispersions (SDs) and evaluated the effect of its degradation by trypsin on drug dissolution from the dispersions. SDs of CS and mefenamic acid (MA) were prepared by physical mixing, kneading, and coprecipitation methods. In comparison to pure MA, the dispersions were evaluated for drug–protein interaction, loss of drug crystalinity, and drug morphology by differential scanning calorimetry, X-ray diffractometry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Drug dissolution from the dispersions was evaluated in simulated intestinal fluid as enzyme free and trypsin-enriched media. Furthermore, in vivo drug absorption of MA from CS-MA coprecipitate was evaluated in rats, in comparison with a reference SD of polyethylene glycol and MA (PEG-MA SD). Relative to other CS preparations, CS-MA coprecipitate showed the highest loss of drug crystallinity, drug micronization, and CS-MA interaction. CS remarkably enhanced the dissolution rate and extent of MA from the physical and kneaded mixtures. However, the highest dissolution enhancement was obtained when MA was coprecipitated with CS. Trypsin that can hydrolyze CS during dissolution resulted in further enhancement of MA dissolution from the physical and kneaded mixtures. However, a corresponding retardation effect was obtained for the coprecipitate. In correlation with in vitro drug release, CS-MA coprecipitate also showed significantly higher MA bioavailability in rats than PEG-MA SD.
Imad I. Hamdan Informa UK Limited
ABSTRACT Determination of residual pharmaceutical compounds in environmental water is gaining increasing interests. The task represents a substantial challenge to analysts because analytes present in quite complicated matrices and at very low concentrations. Despite the inherent low sensitivity associated with capillary electrophoresis (CE), it has been used successfully to determine different types of pharmaceutical compounds at very low levels that rival those reported by more commonly used methods for that purpose such as high performance liquid chromatography-mass spectrometry (HPLC-MS). Attempts to use CE for the determination of drugs in environmental water samples started nearly in the late 1990s; since then, different modes of CE including capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography together with different detection techniques (UV, fluorescence, MS) have been investigated and shown to be of adequate performance. A key to the success of CE for such low-level determination was the sample concentration steps that have been used including solid-phase extraction and more advanced approaches such as in-line sample concentration, large volume sample stacking, and others. The different reports that have been reported for this application in particular have been reviewed since late 1990s with emphasis on the attained limits of detections and sample treatment. The particularities of the separation conditions in each case have been discussed with some elaboration. GRAPHICAL ABSTRACT
Imad I. Hamdan, Mervat Alsous, and Amira Taher Masri Hindawi Limited
Levetiracetam (LVT) is a widely used antiepileptic drug (AED). A less invasive sampling method for therapeutic drug monitoring (TDM) would be very useful particularly for children. Saliva has been shown as an adequate sample for TDM of some AEDs. Due to the high hydrophilicity of LVT its separation on common stationary phases is quite a challenge so that previous methods for determination of LVT in saliva employed either gradient high performance liquid chromatographic (HPLC) system or mass spectrometer as a detector. In this study the retention behavior of LVT on some common stationary phases was examined, with C8 being the most retentive. A simple isocratic HPLC method that is based on simple protein precipitation was developed and validated for the determination of LVT in saliva. The method was applied to a sample group of epileptic children for the purpose of assessing potential correlation with plasma LVT levels and to investigate patient’s compliance. The results confirmed a reasonable correlation between plasma and salivary levels of LVT (R = 0.9) which supports the use of saliva for TDM of LVT. The study also revealed a significant percentage of epileptic patients having LVT levels below the estimated therapeutic range.
Samar H. Thiab, Imad I. Hamdan, Dina El-Sabawi, and Afaf H. Al-Nadaf Springer Science and Business Media LLC
Gliclazide (GZD) is a hypoglycemic agent that has slow dissolution rate and variable bioavailability. Inclusion complex of GZD with hydroxypropyl-β-cyclodextrin (HPβCD) was prepared with the molar ratio 1:2 by solvent evaporation method. The complex was characterized using Fourier transform infra-red spectroscopy and differential scanning calorimetry. Solubility and in vitro dissolution studies were performed at acidic and neutral pH values. Furthermore, the competitive interactions of the antihistamine loratadine (LOR) on the binding of GZD to HPβCD were studied by performing solubility and in vitro dissolution studies of GZD-HPβCD complex in presence and absence of the competing drug at pH values 4.5 and 6.8. GZD-HPβCD complex was found to enhance the dissolution of the drug in all pH values studied. The presence of LOR with GZD-HPβCD complex led to some pH dependent changes in the dissolution of the complex which supported the results obtained from the solubility studies. Using blood glucose level as a pharmacodynamic marker that reflects the bioavailability of GZD, in vivo studies have shown that GZD when given as its HPβCD complex together with LOR exhibits about 25 % lower bioavailability (effect) compared to GZD alone. In an attempt to explain the in vivo and dissolution studies, higher order complexes (aggregates) involving LOR, GZD and HPβCD were proposed. The formation of such larger complexes was supported by stoichiometric and diffusion studies.
Alaa Hammad, Imad Hamdan, and Dina El-Sabawi Dissolution Technologies
The performance of the analytical methodologies recommended by the United States Pharmacopoeia (USP) monograph (1) for dissolution testing of lansoprazole (LPZ) enteric-coated solid dosage forms (capsules/tablets) was critically evaluated. While USP adopts an essentially nonselective UV method, the British Pharmacopoeia (2) recommends a highperformance liquid chromatography (HPLC) method capable of separating the drug from its acid degradation products. For an acid-labile drug such as LPZ, one might think that the nonselective UV method might overor underestimate the percentage released because the degradation product might have UV absorptivity different from that of the parent drug. We subjected six commercial products in addition to the reference product (G) to analysis according to the USP assay and dissolution recommendations. Products were also subjected to dissolution tests whereby a selective HPLC method was employed for quantifying the percentage release. All products passed USP assay tests. For dissolution, the UV method adopted by USP was more reliable because it indicated the actual percentage released compared with the selective HPLC method, which reflected only the percentage of released LPZ that remained intact (undegraded). Only one product (E) failed to satisfy the USP requirements for dissolution.
Interaction of esomeprazole with insulin detemir and human albumin: a potential cause of hypoglycemia
Imad I. Hamdana*, Dua'a GH. Farahb, Enam A. Khalilc, Randa SH. Mansourd, Heba Abdel-Halime.
Biophysical Chemistry, 285, 106809
IR microspectroscopic investigation of the interaction of some losartan salts with human stratum corneum protein and its effect on losartan transdermal permeation. Randa S H Mansour , Aamal Y Al Khawaja , Imad I Hamdan , Enam A Khalil. PLoS One. 2023 Jun 15;18(6):e0287267. doi: 10.1371/.