Rational development of nanomedicines for molecular targeting in periodontal disease.

Recent advances in understanding the etiology and pathogenesis of periodontal disease and polymicrobial synergy in the dysbiotic oral microbial community endorsed novel therapeutic targets and assured further improvement in periodontal disease treatment. Moreover, understanding of the events at the molecular level inspired the researchers to alleviate the stress from the disease by applying the bottom-up approach and delivering the drugs at the site of action, using nanoscale medicines. This review is focused on promising strategies for rational design of nanopaharmaceuticals for periodontal disease treatment based on novel therapeutic targets and the potential of advanced concepts for inflammation cascade targeting. Due to their size, nanomedicines are capable to interact with the elements of the immune system through cell receptor binding and to subsequently influence specific intracellular signaling pathways activation. They might also interfere with different signaling molecules continuously involved in the disease progression, in order to abolish cell activation and block the production of proinflammatory substances. Different biomacromolecules can be trafficked to the site of action using nanomedicines for gene targeting: i) decoy oligodeoxynucleotide (ODN) for suppression of NF-κB transcription activity, ii) DNA therapeutics for modulation of cell inflammatory response and iii) siRNA for cytokine production silencing. However, despite the potential of the nanotechnology for improvement of periodontal disease treatment, the translation of nano-drug delivery systems to clinical therapy is hindered by the lack of standard procedures for proper safety and efficacy profile evaluation.

Chemometric evaluation of the efficacy of locally administered chlorhexidine in patients with periodontal disease.

The process of assessment of drug efficacy produces multivariate data which are difficult to interpret. The interpretation and extraction of relevant data requires application of chemometric algorithms for multivariate data analysis. The aim of our study was evaluation of the efficacy of local treatment with chlorhexidine (CHX) in patients suffering from periodontal disease by chemometric algorithms for multivariate data analysis. Several algorithms were used: principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal projection to latent structures discriminant analysis (OPLS-DA). The PCA models identified the examined variables as suitable for monitoring the periodontal disease progression at the same time revealing mutual relationship among them. The developed PLS-DA model successfully distinguished patients treated with CHX from non-treated patients. The OPLS-DA model revealed differences in the mechanism of action of the two widely applied treatments in periodontal disease, local administration of CHX and local administration of doxycycline (DOX). The approach presented in this study opens the possibility of application of chemometric algorithms for multivariate data analysis for assessment of treatment efficacy.

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.

High-Throughput HPLC-MS/MS Method for Quantification of Ibuprofen Enantiomers in Human Plasma: Focus on Investigation of Metabolite Interference.

In this research, as a part of the development of fast and reliable HPLC-MS/MS method for quantification of ibuprofen (IBP) enantiomers in human plasma, the possibility of IBP acylglucoronide (IBP-Glu) back-conversion was assessed. This involved investigation of in source and in vitro back-conversion. The separation of IBP enantiomers, its metabolite and rac-IBP-d3 (internal standard), was achieved within 6 min using Chiracel OJ-RH chromatographic column (150 × 2.1 mm, 5 µm). The followed selected reaction monitoring transitions for IBP-Glu (m/z 381.4 → 205.4, m/z 381.4 → 161.4 and m/z 205.4 → 161.4) implied that under the optimized electrospray ionization parameters, in source back-conversion of IBP-Glu was insignificant. The results obtained after liquid-liquid extraction of plasma samples spiked with IBP-Glu revealed that the amount of IBP enantiomers generated by IBP-Glu back-conversion was far <20% of lower limit of quantification sample. These results indicate that the presence of IBP-Glu in real samples will not affect the quantification of the IBP enantiomers; thereby reliability of the method was improved. Additional advantage of the method is the short analysis time making it suitable for the large number of samples. The method was fully validated according to the EMA guideline and was shown to meet all requirements to be applied in a pharmacokinetic study.

Efficacy assessment of local doxycycline treatment in periodontal patients using multivariate chemometric approach.

The aim of our study was application of chemometric algorithms for multivariate data analysis in efficacy assessment of the local periodontal treatment with doxycycline (DOX). Treatment efficacy was evaluated by monitoring inflammatory biomarkers in gingival crevicular fluid (GCF) samples and clinical indices before and after the local treatment as well as by determination of DOX concentration in GCF after the local treatment. The experimental values from these determinations were submitted to several chemometric algorithms: principal component analysis (PCA), partial least square discriminant analysis (PLS-DA) and orthogonal projection to latent structures-discriminant analysis (OPLS-DA). The data structure and the mutual relations of the selected variables were thoroughly investigated by PCA. The PLS-DA model identified variables responsible for discrimination of classes of data, before and after DOX treatment. The OPLS-DA model compared the efficacy of the two commonly used medications in periodontal treatment, chlorhexidine (CHX) and DOX, at the same time providing insight in their mechanism of action. The obtained results indicate that application of multivariate chemometric algorithms can be used as a valuable approach for assessment of treatment efficacy.

Optimization of HS-GC-FID-MS Method for Residual Solvent Profiling in Active Pharmaceutical Ingredients Using DoE.

Within this research, a headspace (HS) gas chromatography-flame ionization detector-mass spectrometry method was developed for profiling of residual solvents (RSs) in active pharmaceutical ingredients (APIs). Design of experiment was used for optimization of sample preparation, as well as for robustness testing of the method. HS equilibration temperature and dilution medium were detected as parameters with greater impact on the sensitivity, compared with the time used for equilibration of the samples. Regardless of the sample solubility, the use of water for sample preparation was found to be crucial for better sensitivity. The use of a well-designed strategy for method development and robustness testing, additional level of identification confidence, as well as use of internal standard provided a strong and reliable analytical tool for API fingerprinting, thus enabling the authentication of the substance based on the RS profile.

Critical development by design of a rugged HPLC-MS/MS method for direct determination of ibuprofen enantiomers in human plasma.

Development and validation of a HPLC-MS/MS method for direct determination of R- and S-ibuprofen (Ibu) in human plasma without a need of derivatization or other complexities such as postcolumn infusion of solvents or reagents was performed. Critical steps were investigated during method development using experimental design to achieve a reliable and rugged assay. The LC-MS/MS separation of R-Ibu and S-Ibu was obtained on Lux Cellulose chiral column utilizing 0.1% (v/v) acetic acid in mixture of methanol and water (90:10%, v/v) as a mobile phase. Two types of extraction procedure for Ibu and Ketoprofen (internal standard, IS) were optimized using Full factorial 3(2) design (LLE) and D-Optimal Experimental Design (SPE). Excellent recovery values, 80% (mean) and 95% (mean) for LLE and SPE respectively, were obtained using 50µL plasma. The matrix effect was assessed for both of the extraction procedures, including hyperlipidaemic and haemolyzed plasma. The extensive investigation of matrix effect showed that LLE yields cleaner extracts than the SPE. The result of the investigation of in vitro interconversion of R-Ibu and S-Ibu showed that it does not occur under the influence of pH, temperature, and in the overall analytical procedure. The validation data, adhered to EMA guideline for validation of bioanalytical methods, showed that the proposed method provides accurate and reproducible results in range of 0.1-50mg/L with a lower limit of detection of 0.02mg/L. The applicability of the method was demonstrated through determination of R-Ibu and S-Ibu in human plasma after oral administration of 400mg rac-Ibu.

Fingerprinting of morphine using chromatographic purity profiling and multivariate data analysis.

Chromatographic purity profiling (CPP) is the common name of a group of analytical and chemometric applications for detection, identification and quantitative determination of related substances and other impurities in active pharmaceutical ingredients (APIs) and finished dosage forms (FDFs). CPP is used for fingerprinting and discriminating between samples, thus representing a core activity in modern drug analysis. The worldwide demand for morphine and its congeners is tremendous and depends entirely on the supply of natural opiates. The aim of this research was to develop a methodology that enables identification of a source of morphine, thus revealing falsification of the substance. The characteristic and reproducible features of impurity profiles for 28 samples of morphine (6 morphine sulfate, 9 morphine hydrochloride and 13 morphine base) were captured by a new LC/MS method for impurity profiling of morphine. The impurity profile encompasses the related substances specified in relevant Ph.Eur. monographs, as well as the other morphinane like impurities, including the naturally occurring co-extracted alkaloids. Different pattern recognition techniques (unsupervised and supervised) were used to reveal the differentiation features of the morphine fingerprints for classification and authentication purposes. The results described in this research open the possibility of using the chromatographic purity profile combined with multivariate data analysis for fingerprinting of morphine samples.

Optimization of the formulation for preparing Lactobacillus casei loaded whey protein-Ca-alginate microparticles using full-factorial design.

CONTEXT: This article presents specific approach for microencapsulation of Lactobacillus casei using emulsion method followed by additional coating with whey protein. METHODS: Experimental design was employed using polynomial regression model at 2nd level with three independent variables, concentrations of alginate, whey protein and CaCl2. Physicochemical, biopharmaceutical and biological properties were investigated. RESULTS: In 11 series generated, negatively charged microparticles were obtained, with size 6.99-9.88 µm, Ca-content 0.29-0.47 mg per 10 mg microparticles, and viability of the probiotic 9.30-10.87 log10CFU/g. The viability after 24 hours in simulated gastrointestinal conditions was between 3.60 and 8.32 log10CFU/g. DISCUSSION: Optimal formulation of the microparticles that ensures survival of the probiotic and achieves controlled delivery was determined: 2.5% (w/w) alginate, 3% (w/w) CaCl2 and 3% (w/w) whey protein. CONCLUSION: The advantageous properties of the L. casei-loaded microparticles make them suitable for incorporation in functional food and/or pharmaceutical products.

Development and validation of RP HPLC method for determination of betamethasone dipropionate in gingival crevicular fluid.

Abstract A simple RP HPLC method for quantification of betamethasone dipropionate (BDP) in gingival crevicular fluid (GCF) has been developed and validated. GCF represents a valuable matrix for therapeutic monitoring of drugs used in the treatment of periodontal disease. The proposed method involves single step extraction for sample preparation. The calibration curve for BDP was linear over the concentration range of 0.10-2.00 µg mL⁻¹ (R² = 0.9971). RSD values of intra- and inter-day precision ranged 2.2-4.5 and 1.6-5.7 %, while accuracy values were higher than 96.6 and 97.0 %, respectively. The described method can be successfully applied for determination of betamethasone concentrations in GCF obtained from patients with chronic periodontitis after local treatment with BDP cream 0.5 mg g⁻¹.

Use of chemometrics for development and validation of an RP-HPLC method for simultaneous determination of haloperidol and related compounds.

A rapid resolution reversed-phase high performance liquid chromatographic (RR RP-HPLC) method has been developed and validated for simultaneous determination of haloperidol and six related compounds. Investigated matrix was a laboratory mixture of a therapeutic active substance haloperidol and its six related compounds in concentration ratio 300:1. Experimental design was used during method optimization (full factorial 23 design) and robustness testing (Central Composite Circumscribed design). Three factors: organic phase variation during gradient elution, flow rate and gradient rise time were independent variables. To estimate the system response during the optimization procedure and robustness testing, resolution (Rs) and a chromatographic response function (CRF) were used. Chromatography was performed with the mobile phase containing phosphate buffer pH 6.5 and acetonitrile as organic modifier. Separation was achieved using gradient elution (organic phase fraction changed linearly from 20 to 72 %) over 7 min. A Zorbax Eclipse XDB C18 Rapid Resolution HT 4.6 mm x 50 mm, 1.8 mum particle size, column was used at 25 degrees C at a flow rate of 1.5 mL min-1. UV detection was performed at 230 nm. The total time for chromatographic separation was 5.5 min with a total analysis time of 7.0 min. The method was validated for its linearity, precision, modal recovery and robustness.