Akhtar Siddiqui

Assessing the impact of nimodipine devitrification in the ternary cosolvent system through quality by design approach

Nimodipine (NM) commercial formulation has been recalled due to drug crystallization in the product. Aim of present investigation was to systematically evaluate NM ternary cosolvents systems, characterize the crystallized drug and develop discriminating dissolution method that could detect the drug crystallization in the product. Mixture design was constructed using independent components namely water (X1), glycerin (X2) and polyethylene glycol 400 (X3, PEG-400). Nineteen formulations were developed using various level of cosolvents mixture while drug concentration was kept constant. The response selected was the drug crystallized in the formulations kept at four storage conditions 5 °C, 15 °C, 25 °C and 25 °C/60% RH for four weeks. The crystallized drug was characterized by Fourier transformed infrared (FTIR), near infrared (NIR), NIR-chemical imaging and Raman spectroscopies, powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and scanning electron microscopy. Dissolution of formulation and modification was tested by USP method 2 in 0.25 and 0.50% sodium lauryl sulphate (SLS) aqueous media and run at 50 and 75 rpm. X1 promoted drug crystallization at all conditions of storage and reverse was true for X3. Characterization data indicated that the crystallized drug in most of the formulations were modification II, but a few formulations contained significant proportion of the modification I. Dissolution in 0.25% (w/v) SLS at 75 rpm was more discriminating in detecting the crystallization in the product compared to dissolution in 0.5% (w/v) SLS media. In summary, cosolvents system of NM was prone to crystallization depending upon the cosolvents composition and storage conditions. A more rational approach to develop NM formulation would entail a then through understanding of the causes of crystallization and their characterization in a variety of storage conditions.

Chemometric methods for the quantification of crystalline tacrolimus in solid dispersion by powder X-ray diffractrometry.

The objective of this study was to develop powder X-ray diffraction (XRPD) chemometric model for quantifying crystalline tacrolimus from solid dispersion (SD). Three SDs (amorphous tacrolimus component) with varying drug to excipient ratios (24.4%, 6.7%, and 4.3% drug) were prepared. Placebo SDs were mixed with crystalline tacrolimus to make their composition equivalent to three SD (crystalline tacrolimus component). These two components were mixed to cover 0%-100% of crystalline drug. Uniformity of the sample mixtures was confirmed by near-infrared chemical imaging. XRPD showed three distinct peaks of crystalline drug at 8.5°, 10.3°, and 11.2° (2θ), which were nonoverlapping with the excipients. Principal component regressions (PCR) and partial least square (PLS) regression used in model development showed high R(2) (>0.99) for all the mixtures. Overall, the model showed low root mean square of standard error, standard error, and bias, which was smaller in PLS than PCR-based model. Furthermore, the model performance was evaluated on the formulations with known percentage of crystalline drug. Model-calculated crystalline drug percentage values were close to actual value. Therefore, these studies strongly suggest the application of chemometric-XRPD models as a quality control tool to quantitatively predict the crystalline drug in the formulation.

Chemometric Model Development and Comparison of Raman and 13C Solid-State Nuclear Magnetic Resonance–Chemometric Methods for Quantification of Crystalline/Amorphous Warfarin Sodium Fraction in the Formulations

Warfarin sodium (WS) exists in multiple solid-state forms. The solid-state forms differ in physicochemical properties, and crystalline changes in the drug formulation may influence on the drug product quality and/or clinical performance. It is, therefore, critically important to have a good and reliable analytical method to monitor and quantitate this transformation during stability studies. The aim of the present research was to investigate Raman spectroscopy and solid-state nuclear magnetic resonance ((13)C ssNMR) methods in conjunction with chemometry to quantitate the amorphous and crystalline WS fractions in the drug products. Compositionally identical formulations of amorphous and crystalline WS were prepared, and mixed in various proportions to make 0%-100% amorphous/crystalline sample matrices. Raman and (13)C ssNMR spectra were collected and subjected to partial-least-squares and principle component regressions after mathematical treatment of the data. The model performance parameters such as root-mean-square error of prediction, standard error of prediction, and bias were low for Raman models in comparison to (13)C ssNMR models. Models predicted values of the independent sample matrices match closely with the actual values at high level of crystalline WS. Thus, the developed methods provide means to control and quantitate the WS forms fraction in the drug product.

Orally disintegrating tablet of novel salt of antiepileptic drug: formulation strategy and evaluation.

The aim of present research was to design and evaluate orally disintegrating tablet (ODT) of novel lamotrigine-cyclamate salt. Box-Behnken response surface methodology was selected to design the optimized formulation. The independent factors selected were tablet hardness (X1), disintegrant (X2) and lubricant (X3) levels, and responses chosen were disintegration time (DT, Y1), friability (Y2), T50 (Y3), and T90 (Y4). The tablets were also characterized for drug uniformity by near infrared chemical imaging (NIR-CI) and taste masking evaluation by electronic tongue. All the selected independent variables were statistically (p<0.05) effect the Y1 while Y2, Y3, and Y4 affected only by X2. The optimized ODT was found to meet the regulatory requirement of DT and friability specification. The NIR-CI images indicated uniform distribution of active and inactive ingredients within the tablets. The electronic tongue results were analyzed by principle component analysis (PCA). It indicated that novel salt of lamotrigine and its ODT formulation have a taste similar to cyclamic acid which is indicated by close proximity on PCA score plot, lower Euclidean distance, and high discrimination index values. Furthermore, these parameters were very close to ODT placebo formulation. On the other hand, lamotrigine, its ODT, and placebo formulation were far from each other. In summary, lamotrigine salt provides another avenue for pediatric friendly formulation for children and will enhance patience compliance.

Root cause evaluation of particulates in the lyophilized indomethacin sodium trihydrate plug for parenteral administration

Particulate growth in parenteral product frequently results in product recalls causing drug shortages. While this is mostly attributed to quality issues in a firm, particulates growth could also be due to inadequate product, process, or environmental understanding. Therefore, the objective of this study was to use indomethacin sodium trihydrate (drug) as a model drug for lyophilization and evaluates short-term stability with respect to particulate growth at different storage temperatures. Under aseptic condition, each vial filled with filtered drug solution was lyophilized, and stoppered in LyoStar3. Crimped vials were kept at 5°C, 15°C, 25°C, 25°C/60%RH, and 40°C/75%RH. At predefined time interval, samples were characterized using X-ray powder diffraction (XRPD), thermal, and spectroscopic method. Lyophilized formulation showed four thermal events: 60-90°C demonstrating glass transition, 110-160°C showing recrystallization exotherm,170-220°C exhibiting endotherm of potential polymorph, and 250°C showing melting endotherm. XRPD of the lyophilized powder demonstrated peak at 2 θ 11.10. Spectroscopic studies of lyophilized powder indicated alteration in symmetric and asymmetric carboxylate peaks over time indicating initiation of crystallization and crystal growth. Reconstitution studies indicated higher reconstitution time after six weeks for sample stored at 40°C/75%RH. Furthermore, reconstituted solution showed presence of particulates after 8 weeks storage. These studies suggest that particulate growth can stem from poorly developed formulation and not necessarily due to frequently ascribed filtration issues.

Application of NIR chemometric methods for quantification of the crystalline fraction of warfarin sodium in drug product

Abstract Monitoring of the physical state of warfarin sodium (WS) in products is essential for minimizing product quality variability in order to ensure consistent clinical performance. This study reports the development of chemometric models for quantifying the crystalline and amorphous fractions of WS in commercial drug products using NIR spectroscopy. Formulations based on commercially available products with different API to excipient ratio were used for the study. For each content, two formulations containing either lactose monohydrate or lactose anhydrous as the predominant formulation excipient were prepared. Two formulations containing either 100% amorphous WS (AWS) or crystalline WS (CWS) were prepared and mixed in various ratios to obtain sample matrices containing AWS/CWS 0–100%. The uniformity of the samples was confirmed by near infrared chemical imaging. Data were mathematically pretreated by multiplicative signal correction and Savitzky–Golay second derivative. Principal component regression and partial least square regression models were developed from mathematically treated data. All the models showed linear trend for amorphous and crystalline fractions of the WS as indicated by correlation and R2 > 0.99 and >0.98, respectively. The models demonstrated good performance parameters with a low-root mean squared error, standard error and bias. The model predicted CWS and AWS contents were in very close agreement with the actual values. The study indicated the utility of NIR chemometric methods in quantification of the crystalline and/or amorphous fraction of WS in its products.

Comparison of X-ray Powder Diffraction and Solid-State Nuclear Magnetic Resonance in Estimating Crystalline Fraction of Tacrolimus in Sustained-Release Amorphous Solid Dispersion and Development of Discriminating Dissolution Method

The focus of present investigation was to explore X-ray powder diffraction (XRPD) and solid-state nuclear magnetic resonance (ssNMR) techniques for amorphous and crystalline tacrolimus quantification in the sustained-release amorphous solid dispersion (ASD), and to propose discriminating dissolution method that can detect crystalline drug. The ASD and crystalline physical mixture was mixed in various proportions to make sample matrices containing 0%-100% crystalline-amorphous tacrolimus. Partial-least-square regression and principle component regression were applied to the spectral data. Dissolution of the ASD in the US FDA recommended dissolution medium with and without surfactant was performed. R(2) > 0.99 and slope was close to one for all the models. Root-mean-square of prediction, standard error of prediction, and bias were higher in ssNMR-based models when compared with XRPD data models. Dissolution of the ASD decreased with an increase in the crystalline tacrolimus in the formulations. Furthermore, detection of crystalline tacrolimus in the ASD was progressively masked with an increase in the surfactant level in the dissolution medium. XRPD and ssNMR can be used equally to quantitate the crystalline and amorphous fraction of tacrolimus in the ASD with good accuracy; however, ssNMR data collection time is excessively long, and minimum surfactant level in the dissolution medium maximizes detection of crystalline reversion in the formulation.

Assessing impact of formulation and process variables on in-vitro performance of directly compressed abuse deterrent formulations.

Prescription drug products abuse/misuse is epidemic in United States. Opioids drug forms major portion of prescription drug product abuse. Abuse deterrence formulation (ADF) is one of the many approaches taken by sponsors to tackle this problem. It involves formulating opioids into dosage forms that will be difficult to abuse/misuse. Current investigation focused on evaluating the abuse deterrent properties (ADP) of ADF manufactured by direct compression method. Effect of process and formulation variables on ADP was investigated by statistical design of experiment (fractional factorial design). Independent factors studied were molecular weight of polyethylene oxide (Polyox™), curing time, temperature and method, and antioxidant type. Sotalol hydrochloride was selected as a model drug. ADP investigated were hardness/crush resistance, syringeability and injectability, physical manipulation (reduction into powder) and drug extraction in water and alcohol. Hardness and syringeability are evaluated by newly developed quantitative procedure. Other properties were also investigated such as morphology, crystallinity, assay and dissolution. The hardness and drug extraction was significantly (p<0.05) affected by curing temperature. Formulations could be powdered in 3 min irrespective of their hardness. Syringeability and injectability were intrinsic properties of the polymer used in the formulation, and were not affected by the investigated factors. Crystallinity of the polymer and drug changed, and was dependent upon curing temperature and time. The dissolution and assay were independent of formulation and process parameters studied. In conclusion, the study indicated some advantages of ADF product compared to non-ADF prepared by direct compression. However, the ADF should not be viewed as abuse proof product rather as incrementally improved product.

Development and validation of X-ray diffraction method for quantitative determination of crystallinity in warfarin sodium products ☆

The objective of this study was to develop and validate XRPD analytical method for the estimation of percent crystalline warfarin sodium present in drug products. Warfarin sodium (WS) is a clathrate containing Isopropyl alcohol entrapped in the crystalline structure. Four types of WS-excipient mixtures were prepared and used to make four formulations: M1 containing lactose monohydrate (WS: excipient 1:9), M2 containing anhydrous lactose (WS: excipient 1:9), M3 containing lactose monohydrate (WS: excipient 1:21.5), M4 containing lactose anhydrous (WS: excipient 1:21.5). Thoroughly mixed powders were packed in the XRD sample holders and diffractogram were collected. Diffractogram in the 7-9 2θ were found to be distinctive as the peak intensity grows with increasing percent crystalline WS. This peak region was, therefore, used to validate the XRPD method. Validation parameters were evaluated for accuracy, precision, linearity, limit of detection (LOD), and limit of quantitation (LOQ). LOD and LOQ for M1, M2, M3, and M4 were 3.04, 3.17, 4.17, 4.49% and 9.21, 9.62, 12.65, 13.30%, respectively. The method was found to be linear with R(2)>0.99. With changing scan speed, X-ray power output, and type of sample holder, the method was found to be robust. Prediction of the % crystalline content of the WS sample with known crystallinity showed close agreement between actual and predicted value. In summary, XRPD method was validated, which can be used as a quantitative method for the estimation of % crystalline WS present in a drug product.

Near-Infrared and Fourier Transform Infrared Chemometric Methods for the Quantification of Crystalline Tacrolimus from Sustained-Release Amorphous Solid Dispersion

The objective of the present research was to study the feasibility of using near-infrared (NIR) and Fourier transform infrared (FTIR)-based chemometric models in quantifying crystalline and amorphous tacrolimus from its sustained-release amorphous solid dispersion (ASD). ASD contained ethyl cellulose, hydroxypropyl methyl cellulose, and lactose monohydrate as carriers, and amorphous form of tacrolimus in it was confirmed by X-ray powder diffraction. Crystalline physical mixture was mixed with ASD in various proportions to prepare sample matrices containing 0%-100% amorphous/crystalline tacrolimus. NIR and FTIR of the samples were recorded, and data were mathematically pretreated using multiple scattering correction, standard normal variate, or Savitzky-Golay before multivariate analysis, partial-least-square regression (PLSR), and principle component regression (PCR). The PLSR models were more accurate than PCR for NIR and FTIR data as indicated by low value of root-mean-squared error of prediction, standard error of prediction and bias, and high value of R(2). Additionally, NIR data-based models were more accurate and precise than FTIR data models. In conclusion, NIR chemometric models provide simple and fast method to quantitate crystalline tacrolimus in the ASD formulation.