Identification of drugs in pharmaceutical dosage forms by X-ray powder diffractometry

Insight into the Inclusion Complexation of Fluconazole with Sulfonatocalix[4]naphthalene in Aqueous Solution, Solid-State, and Its Antimycotic Activity

The study aims to assess the interaction between fluconazole and sulfonatocalix[4]naphthalene towards enhancing its dissolution performance and antimycotic activity. A solubility study was carried out at different pH conditions, and the results revealed the formation of a 1:1 molar ratio fluconazole-sulfonatocalix[4]naphthalene inclusion complex with an A_L type phase solubility diagrams. The solid powder systems of fluconazole-sulfonatocalix[4]naphthalene were prepared using kneaded and co-evaporation techniques and physical mixtures. DCS, PXRD, TGA-DTG, FT-IR, and in vitro dissolution performance characterize the prepared systems. According to physicochemical characterization, the co-evaporation approach produces an amorphous inclusion complex of the drug inside the cavity of sulfonatocalix[4]naphthalene. The co-evaporate product significantly increased the drug dissolution rate up to 93 ± 1.77% within 10 min, unlike other prepared solid powders. The antimycotic activity showed an increase substantially (p ≤ 0.05, t-test) antimycotic activity of fluconazole co-evaporate mixture with sulfonatocalix[4]naphthalene compared with fluconazole alone against clinical strains of Candida albicans and Candida glabrata. In conclusion, sulfonatocalix[4]naphthalene could be considered an efficient complexing agent for fluconazole to enhance its aqueous solubility, dissolution performance, and antimycotic activity.

Current and Future Perspective of Devices and Diagnostics for Opioid and OIRD

OIRD (opioid-induced respiratory depression) remains a significant public health concern due to clinically indicated and illicit opioid use. Respiratory depression is the sine qua non of opioid toxicity, and early detection is critical for reversal using pharmacologic and non-pharmacologic interventions. In addition to respiratory monitoring devices such as pulse oximetry, capnography, and contactless monitoring systems, novel implantable sensors and detection systems such as optical detection and electrochemical detection techniques are being developed to identify the presence of opioids both in vivo and within the environment. These new technologies will not only monitor for signs and symptoms of OIRD but also serve as a mechanism to alert and assist first responders and lay rescuers. The current opioid epidemic brings to the forefront the need for additional accessible means of detection and diagnosis. Rigorous evaluation of safety, efficacy, and acceptability will be necessary for both new and established technologies to have an impact on morbidity and mortality associated with opioid toxicity. Here, we summarized existing and advanced technologies for opioid detection and OIRD management with a focus on recent advancements in wearable and implantable opioid detection. We expect that this review will serve as a complete informative reference for the researchers and healthcare professionals working on the subject and allied fields.

X-ray fan beam coded aperture transmission and diffraction imaging for fast material analysis

X-ray transmission imaging has been used in a variety of applications for high-resolution measurements based on shape and density. Similarly, X-ray diffraction (XRD) imaging has been used widely for molecular structure-based identification of materials. Combining these X-ray methods has the potential to provide high-resolution material identification, exceeding the capabilities of either modality alone. However, XRD imaging methods have been limited in application by their long measurement times and poor spatial resolution, which has generally precluded combined, rapid measurements of X-ray transmission and diffraction. In this work, we present a novel X-ray fan beam coded aperture transmission and diffraction imaging system, developed using commercially available components, for rapid and accurate non-destructive imaging of industrial and biomedical specimens. The imaging system uses a 160 kV Bremsstrahlung X-ray source while achieving a spatial resolution of ≈ 1 × 1 mm² and a spectral accuracy of > 95% with only 15 s exposures per 150 mm fan beam slice. Applications of this technology are reported in geological imaging, pharmaceutical inspection, and medical diagnosis. The performance of the imaging system indicates improved material differentiation relative to transmission imaging alone at scan times suitable for a variety of industrial and biomedical applications.

Solid-State Characterization and Compatibility Studies of Penciclovir, Lysine Hydrochloride, and Pharmaceutical Excipients

The physical and chemical characterization of the solid-state properties of drugs and excipients is fundamental for planning new formulations and developing new strategies for the treatment of diseases. Techniques such as differential scanning calorimetry, thermogravimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy are among the most commonly used techniques for these purposes. Penciclovir and lysine are individually used to treat the herpes virus. As such, the development of a formulation containing both drugs may have therapeutic potential. Solid-state characterization showed that both penciclovir and lysine were crystalline materials with melting points at 278.27 °C and 260.91 °C, respectively. Compatibility studies of penciclovir and lysine indicated a possible interaction between these substances, as evidenced by a single melting point at 253.10 °C. The compatibility of several excipients, including ethylenediaminetetraacetic acid, cetostearyl alcohol, sodium lauryl sulphate, di-tert-butyl methyl phenol, liquid petrolatum, methylparaben, nonionic wax, paraffin, propylene glycol, and propylparaben, was evaluated in ternary (penciclovir-lysine-excipient) mixtures (1:1:1, w/w/w) to determine the optimal formulation. The developed formulation was stable under accelerated and ambient conditions, which demonstrated that the interaction between penciclovir and lysine was suitable for the development of a formulation containing both drugs.

Recognition of Pharmacological Bi-Heterocyclic Compounds by Using Terahertz Time Domain Spectroscopy and Chemometrics

In this study, we presented the concept and implementation of a fully functional system for the recognition of bi-heterocyclic compounds. We have conducted research into the application of machine learning methods to correctly recognize compounds based on THz spectra, and we have described the process of selecting optimal parameters for the kernel support vector machine (KSVM) with an additional `unknown' class. The chemical compounds used in the study contain a target molecule, used in pharmacy to combat inflammatory states formed in living organisms. Ready-made medical products with similar properties are commonly referred to as non-steroidal anti-inflammatory drugs (NSAIDs) once authorised on the pharmaceutical market. It was crucial to clearly determine whether the tested sample is a chemical compound known to researchers or is a completely new structure which should be additionally tested using other spectrometric methods. Our approach allows us to achieve 100% accuracy of the classification of the tested chemical compounds in the time of several milliseconds counted for 30 samples of the test set. It fits perfectly into the concept of rapid recognition of bi-heterocyclic compounds without the need to analyse the percentage composition of compound components, assuming that the sample is classified in a known group. The method allows us to minimize testing costs and significant reduction of the time of analysis.

Preparation and functionalization of acetylsalicylic acid loaded chitosan/gelatin membranes from ethanol-based suspensions via electrophoretic deposition

Ethanol dissolved acetylsalicylic acid was successfully loaded with chitosan/gelatin via EPD and showed outstanding osteogenesis and mechanical properties.

An overview of forensic drug testing methods and their suitability for harm reduction point-of-care services

Given the current opioid crisis around the world, harm reduction agencies are seeking to help people who use drugs to do so more safely. Many harm reduction agencies are exploring techniques to test illicit drugs to identify and, where possible, quantify their constituents allowing their users to make informed decisions. While these technologies have been used for years in Europe (Nightlife Empowerment & Well-being Implementation Project, Drug Checking Service: Good Practice Standards; Trans European Drugs Information (TEDI) Workgroup, Factsheet on Drug Checking in Europe, 2011; European Monitoring Centre for Drugs and Drug Addiction, An Inventory of On-site Pill-Testing Interventions in the EU: Fact Files, 2001), they are only now starting to be utilized in this context in North America. The goal of this paper is to describe the most common methods for testing illicit substances and then, based on this broad, encompassing review, recommend the most appropriate methods for testing at point of care.Based on our review, the best methods for point-of-care drug testing are handheld infrared spectroscopy, Raman spectroscopy, and ion mobility spectrometry; mass spectrometry is the current gold standard in forensic drug analysis. It would be prudent for agencies or clinics that can obtain the funding to contact the companies who produce these devices to discuss possible usage in a harm reduction setting. Lower tech options, such as spot/color tests and immunoassays, are limited in their use but affordable and easy to use.

Comprehensive Characterisation of the Innovator Product: Targeting Bioequivalent Generics

Generic products are cost effective and speedy surrogates for high-priced innovator/branded products. The prerequisite for the development of a generic product is therapeutic equivalence (comprising pharmaceutical equivalence and bioequivalence) to the innovator product, thus ensuring comparable efficacy and safety profile. The probability of successfully developing a bioequivalent product can be improved by developing a formulation equivalent to the reference listed drug (RLD), in terms of the quantitative, solid-state characteristics of the active pharmaceutical ingredient (API) and the manufacturing process. This can be achieved by a systematic and thorough characterisation of the RLD. The present study was aimed at developing a methodology for characterisation of ranitidine hydrochloride tablets, with special emphasis on the solid-state characterisation of the API in the tablet.

A differential solubility method was employed for the separation and quantification of excipients present in the tablet. Solid-state properties were characterised using a range of microscopic, thermal, spectroscopic and crystallographic techniques. In addition, results were confirmed by preparing inhouse tablets of the polymorphic forms I and II, using the decoded quantitative formula.

Characterization of polymorphic ampicillin forms

In this work polymorphs of α-aminobenzylpenicillin (ampicillin), a β-lactamic antibiotic, were prepared and investigated by several experimental and theoretical methods. Amorphous monohydrate and three crystalline forms, the trihydrate, the crystal form I and the crystal form II, were investigated by FT-IR and micro-Raman. Also data obtained by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD) and hot-stage Raman spectroscopy are reported. Finally, quantum mechanical calculations were performed by density functional theory (DFT) to assist the assignment of spectroscopic experimental bands. For the first time, the ampicillin molecule in its zwitterionic form was studied at the B3LYP/aug-cc-pVDZ level and the corresponding theoretical vibrational spectra were computed. In fact, ampicillin in the crystal is in zwitterionic form and concentrations of this same form are quite relevant in solutions at physiological pH. Experimental and theoretical results allowed identification of specific features for polymorph characterization. Bands typical of the different polymorphs are identified both in IR and Raman spectra: in particular in the NH stretching region (IR), in the amide I+δNH region (both techniques), in the 1520-1490cm(-1) region (IR), in the 1320-1300cm(-1) and 1280-1220cm(-1) (IR), in the 1200-1170cm(-1) (Raman), in the amide V region (IR), and, finally, in the 715-640cm(-1) and 220-200cm(-1) (Raman). Interconversion among different polymorphs was investigated by hot-stage Raman spectroscopy and thermal analysis, clarifying the complex pattern of transformations undergone as a function of temperature and heating rate. In particular, DSC scans show how the trihydrate crystals transform into anhydrous forms on heating. Finally, stability tests demonstrated, after a two years period, that no transformation or degradation of the polymorphs occurred.

Polymorphism: an evaluation of the potential risk to the quality of drug products from the Farmácia Popular Rede Própria

Polymorphism in solids is a common phenomenon in drugs, which can lead to compromised quality due to changes in their physicochemical properties, particularly solubility, and, therefore, reduce bioavailability. Herein, a bibliographic survey was performed based on key issues and studies related to polymorphism in active pharmaceutical ingredient (APIs) present in medications from the Farmácia Popular Rede Própria. Polymorphism must be controlled to prevent possible ineffective therapy and/or improper dosage. Few mandatory tests for the identification and control of polymorphism in medications are currently available, which can result in serious public health concerns.

Characterization of a nonribosomal peptide antibiotic solid dispersion formulation by process analytical technologies sensors

The focus of present investigation was to characterize and evaluate the variability of solid dispersion (SD) of amorphous vancomycin (VCM), utilizing crystalline polyethylene glycol (PEG-6000) as a carrier and subsequently, determining their percentage composition by nondestructive method of process analytical technology (PAT) sensors. The SD were prepared by heat fusion method and characterized for physicochemical and spectral properties. Enhanced dissolution was shown by the SD formulations. Decreased crystallinity of PEG-6000 was observed indicating that the drug was present as solution and dispersed form within the polymer. The SD formulations were homogenous as shown by near infrared (NIR) chemical imaging data. Principal component analysis (PCA) and partial least square (PLS) method were applied to NIR and PXRD (powder X-ray diffraction) data to develop model for quantification of drug and carrier. PLS of both data showed correlation coefficient >0.9934 with good prediction capability as revealed by smaller value of root mean square and standard error. The model based on NIR and PXRD were two folds more accurate in estimating PEG-6000 than VCM. In conclusion, the drug dissolution from the SD increased by decreasing crystallinity of PEG-6000, and the chemometric models showed usefulness of PAT sensor in estimating percentage of both VCM and PEG-600 simultaneously.

Formulation and evaluation of a protein-loaded solid dispersions by non-destructive methods

The purpose of this investigation was to develop solid dispersion (SD) formulation of cyclosporine (CyA) using polyethylene glycol (PEG-6000) to enhance its dissolution rate followed by nondestructive method for the prediction of both drug and carrier. SD formulations were prepared by varying the ratio of CyA and PEG-6000 by solvent evaporation technique and characterized by dissolution, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), powder X-ray diffraction (PXRD), near infrared (NIR) and near infrared chemical imaging (NIR-CI). Dissolution data revealed enhanced dissolution of CyA when compared with pure CyA. DSC results showed that the crystallinity of PEG-6000 has decreased as indicated by decrease in the enthalpy of fusion and melting peak in the formulations. FTIR data demonstrated no chemical interaction between drug and carrier. The surface morphology of SD formulations was similar to PEG-6000 particle. NIR-CI disclosed homogeneity of SD matrix as indicated by symmetrical histograms with smaller values of skewness. Similar to NIR, a multivariate peak evaluation with principal component analysis and partial least square (PLS) were carried out with PXRD spectral data. PLS models with both techniques showed good correlation coefficient and smaller value of root mean square of errors. The accuracy of model for predicting CyA and PEG-6000 in NIR and PXRD data were 5.22%, 5.35%, 5.27%, and 2.10%, respectively. In summary, chemometric applications of non-destructive method sensors provided a valuable means of characterization and estimation of drug and carrier in the novel formulations.

Physical-Chemical Characterization and Polymorphism Determination of Two Nimodipine Samples Deriving from Distinct Laboratories

Knowing the characteristics of raw materials in pharmaceutical practice is both important and useful. Firstly, evaluating the physical-chemical properties of the substances that will be used must be the primary step for quality control in the pharmacy industry. This work aims at analyzing the physical-chemical characteristics of two nimodipine samples I and II derived from distinct laboratories through thermal analysis (DSC and TG/DTG), HPLC, crystallography, and microscopy. Thermal analysis showed that sample II was more unstable than I. Morphological differences concerning shape, size, and crystallinity of particles were visualized by scanning electron microscopy (SEM) and X-ray powder diffraction. To sum up, the techniques used in this study can be said to have been efficient in the characterization and evaluation of quality control of the raw material.

X-Ray Powder Diffraction Patterns for Certain .BETA.-Lactam, Tetracycline and Macrolide Antibiotic Drugs

X-ray powder diffraction (XRD) data for eight beta-lactam viz., ampicillin sodium, ampicillin trihydrate, penicillin G procaine, benzathine penicillin, benzyl penicillin sodium, cefalexin, cefotaxime sodium and ceftriaxone sodium; three tetracyclines viz., doxycycline hydrochloride, oxytetracycline dihydrate and tetracycline hydrochloride; and two macrolide viz., azithromycin and erythromycin estolate antibiotic drugs were obtained using a powder diffractometer. The drugs were scanned from Bragg angles (2theta) of 10 degrees to 70 degrees. The obtained data were tabulated in terms of the lattice spacing (A) and relative line intensities (I/I(I)). This new information may be useful for identifying these drugs from confiscated materials, which has been frequently encountered in forensic laboratories.

Solid-state analysis of the active pharmaceutical ingredient in drug products

The solid form of a drug substance is important when developing a new chemical entity. The crystalline form used in development is significant based on possible manufacturability, solubility, bioavailability and stability differences between the solid forms. Regulatory issues require that the form present in a solid dosage form or liquids containing undissolved drug substance be identified. Drug product samples can be analyzed by a variety of techniques to determine the crystal form present or changes that occur during the manufacture of a drug product. The form present will affect development, regulatory and intellectual property issues.

FT-IR and Raman spectroscopic methods for identification and quantitation of orthorhombic and monoclinic paracetamol in powder mixes

FT-IR and Raman spectroscopic methods are suggested for identification of orthorhombic (form II) and monoclinic (form I) paracetamol and for their quantitative determination in mixes. The intensity ratio of the 836 cm(-1) FT-IR band (attributed to the presence of both forms) to the 806 cm(-1) monoclinic band plotted against the inverse monoclinic molar fraction (X) yields a straight line: I(836)/I(806)=0.515/X+0.700, r=0.9965 for eight calibration points on the regression line. Similarly, the area under the 454 cm(-1) band in FT-Raman spectra (which is attributed to both forms) over the area under the 465 cm(-1) band of monoclinic form is inversely related to its molar fraction (X): A(454)/A(465)=0.482/X-0.324, r=0.9954 for eight calibration points. Precision (RSD%) was <5% for both methods. Linear regression analysis between content and intensity of characteristic XRD reflections for four different samples gave r=0.9964 at 4.62 A and r=0.9894 at 3.70 A, for form II. For the content of form I, r=0.9596 at 3.37 A. The limit of detection for monoclinic form was estimated to be 0.012 mole fraction for both methods.

Detection of low levels of the amorphous phase in crystalline pharmaceutical materials by thermally stimulated current spectrometry

PURPOSE

To demonstrate the applicability of thermally stimulated current (TSC) spectrometry for the detection of low levels of the amorphous phase in crystalline pharmaceutical materials.

METHODS

A crystalline drug substance was melt quenched to produce an amorphous material. Blends of the crystalline and amorphous phases in different ratios (from 75:25 to 99:01) were prepared by serial dilution. TSC studies were performed by applying an electric field at a temperature above the glass transition temperature (Tg) to orient the dipoles, rapidly cooling to 0 degrees C, short circuiting for 1 min, and scanning at 7 degrees C/min to measure the depolarization current. The temperature of the peak in the spectrum corresponds to the Tg of the amorphous phase. Modulated differential scanning calorimtery (DSC) studies were performed using three different test protocols (varying linear heating rate, modulation amplitude, and time period). Powder X-ray diffraction (XRD) studies were performed using a Siemens D500 diffractometer.

RESULTS

The ability to detect the amorphous phase by powder XRD is beset with problems due to indirect inference, orientation effects, and instrument-related intensity variations. Even using a consistent sampling procedure and an internal standard, the XRD could quantify the amorphous phase at a level of 5%. In the conventional or modulated DSC, the amorphous phase manifests itself as a shift in the baseline. Using modulated DSC it was possible to detect the amorphous phase at a level of 5% when tested at a heating rate of 2 degrees C/min and an amplitude of +/-1.0 degrees C with a period of 30 s. The moisture sorption method appears to have a similar detection capability. In TSC scans, the glass transition event due to molecular/segmental mobility in the amorphous phase was manifested as a peak/shoulder on the low-temperature side of the depolarization peak of the crystalline phase. The amorphous phase was unambiguously detected at 2% with a lower detection limit of approximately 1%.

CONCLUSIONS

On the basis of the results of this preliminary investigation, TSC appears to be capable of detecting the amorphous phase at as low as approximately 1% in crystalline pharmaceuticals, thus offering a much needed capability in discerning factors.

Solid-state study of polymorphic drugs: carbamazepine

Polymorphs of a compound have solid crystalline phases with different internal crystal lattices; in pharmaceuticals, differences due to polymorphism and pseudopolymorphism can affect bioavailability and effective clinical use. The aim of this work was to obtain the different polymorphic modifications of the anticonvulsant drug, carbamazepine, and to characterise them by means of typical structure-sensitive analytical techniques, such as FT-IR spectroscopy, XRPD and DSC. Further investigations were also performed by Hot Stage FT-IR thermomicroscopy, which permitted the visible and spectroscopic characterisation of the polymorphic forms during heating. Our results confirm the existence of three different polymorphic forms for anhydrous carbamazepine: Form III, the commercial one, Form I, obtained by heating Form III and Form II, crystallised from ethanolic solution. Substantial differences were detected among the polymorphs with regard to solid-state properties. Moreover, Hot Stage FT-IR thermomicroscopy proved its analytical potential to characterise the drug's polymorphism.