The Use of Calcium Phosphate-Based Starter Pellets for the Preparation of Sprinkle IR MUPS Formulation of Rosuvastatin Calcium.

Sprinkle formulations represent an interesting concept of medicinal products aimed at the steadily growing population of patients suffering from swallowing difficulties (dysphagia). In the present work, immediate-release sprinkle MUPS (multiple-unit pellet system) containing rosuvastatin calcium as a model drug substance was successfully developed. The formulation was prepared by drug layering technique using novel calcium phosphate-based starting pellets (PharSQ® Spheres CM) of three different particle sizes. The study showed that the developed multiparticulates were characterized by uniform distribution of coating layers thickness, as well as fast dissolution rate (more than 85% of rosuvastatin calcium dissolved within 30 min, as required by the relevant USP/NF monograph). Rosuvastatin calcium, like other statins, has a bitter, unpleasant taste. Investigations conducted with an electronic tongue suggested that the developed formulation achieved the desired taste-masking efficiency. The effect was found to be particle size-dependent, improving as the size of the multiparticulates increased.

Towards the Continuous Manufacturing of Liquisolid Tablets Containing Simethicone and Loperamide Hydrochloride with the Use of a Twin-Screw Granulator.

Continuous manufacturing is becoming the new technological standard in the pharmaceutical industry. In this work, a twin-screw processor was employed for the continuous production of liquisolid tablets containing either simethicone or a combination of simethicone with loperamide hydrochloride. Both active ingredients present major technological challenges, as simethicone is a liquid, oily substance, and loperamide hydrochloride was used in a very small amount (0.27% w/w). Despite these difficulties, the use of porous tribasic calcium phosphate as a carrier and the adjustment of the settings of the twin-screw processor enabled the optimization of the characteristics of the liquid-loaded powders and made it possible to efficiently produce liquisolid tablets with advantages in physical and functional properties. The application of chemical imaging by means of Raman spectroscopy allowed for the visualization of differences in the distribution of individual components of the formulations. This proved to be a very effective tool for identifying the optimum technology to produce a drug product.

Development of Safirinium dyes for new applications: fluorescent staining of bacteria, human kidney cells, and the horny layer of the epidermis.

Low-molecular synthetic fluorophores are convenient tools in bioimaging applications. Several derivatives of Safirinium dyes as well as their reactive N-hydroxysuccinimide (NHS) esters bearing diverse substituents were synthesized and evaluated experimentally in terms of their lipophilicity by means of reverse-phase and immobilized artificial membrane high-performance liquid chromatography. Subsequently, the selected compounds were employed as novel cellular imaging agents for staining Gram-positive and Gram-negative bacteria, human kidney cell line, as well as human skin tissue. The analyzed dyes allowed for visualization of cellular structures such as mitochondria, endoplasmic reticulum, and cellular nuclei. They proved to be useful in fluorescent staining of stratum corneum, especially in the aspect of xenobiotic exposure and its penetration into the skin. The best results were obtained with the use of moderately lipophilic NHS esters of Safirinium Q. The development of Safirinium dyes is a promising alternative for commercially available dyes since the reported molecules have low molecular masses and exhibit efficient staining and remarkable water solubility. Moreover, they are relatively simple and low-cost in synthesis.

Comparative study of the percutaneous permeation and bioaccumulation of a cyclic siloxane using frozen-thawed and nonfrozen ex vivo human skin.

Literature shows contradictory information regarding the effect of freezing the excise skin ex vivo on the diffusion of substances into the skin. Few studies indicate that storing the human or animal skin in a frozen state decreases the barrier properties after thawing. Therefore, to understand the properties of frozen skin, we evaluated the effect of storage of ex vivo human skin (2 weeks at -20 °C) on the penetration of stratum corneum and permeation into deeper skin layers (epidermis, and dermis) as well as to the receptor fluid by octamethylcyclotetrasiloxane (D4) a representative test compound of cyclic siloxanes. The main research were preceded by checking the integrity of nonfrozen ex vivo human skin in comparison to the frozen-thawed one by using the Electrical Resistance technique (ER) and the fluorescence microscopy. Samples collected in the skin absorption experiment were analyzed by gas chromatography equipped with a flame ionization detector (GC-FID). The results of this study demonstrated that freezing of excised ex vivo human skin at -20 °C for up to 14 days does not alter the permeability of D4 in a statistically significant manner. Thus, our results confirmed the validity of using skin storage conditions for testing the penetration and permeation of xenobiotics recommended by the OECD, EMA, and WHO guidelines.

Directly compressible formulation of immediate release rosuvastatin calcium tablets stabilized with tribasic calcium phosphate.

Reliable and stable tablet formulations for rosuvastatin calcium (RSC) in four strengths: 5 mg, 10 mg, 20 mg, and 40 mg have been developed. Rosuvastatin is a cholesterol-lowering statin drug and is known to be unstable during storage. The possibility of its stabilization with inorganic salts of multivalent metals has already been reported in the literature. In the present study, a special grade of tribasic calcium phosphate excipient was used to chemically stabilize RSC in a directly compressible immediate release tablet formulation. The developed tablets exhibited good mechanical properties (breaking force ranging from 177 N to 250 N depending on tablet strength), rapid disintegration (less than three minutes) and fast dissolution rate (85% of the drug substance dissolved within 15 minutes) as well as satisfactory chemical stability during storage under stress conditions (50 °C/80% RH), even compared to the reference commercial product.

Mangiferin and Hesperidin Transdermal Distribution and Permeability through the Skin from Solutions and Honeybush Extracts (Cyclopia sp.)-A Comparison Ex Vivo Study.

Polyphenolic compounds-mangiferin and hesperidin-are, among others, the most important secondary metabolites of African shrub Cyclopia sp. (honeybush). The aim of this study was to compare the percutaneous absorption of mangiferin and hesperidin from solutions (water, ethanol 50%, (v/v)) and extracts obtained from green and fermented honeybush (water, ethanol 50%, (v/v)). Research was performed with the Bronaugh cells, on human dorsal skin. The mangiferin and hesperidin distributions in skin layers (stratum corneum, epidermis, and dermis) and in acceptor fluid (in every 2, 4, 6, and 24 h) were evaluated by HPLC-Photodiode Array Coulometric and Coulometric Electrochemical Array Detection. The transdermal distribution of hesperidin was also demonstrated by fluorescence microscopy. Results indicated that mangiferin and hesperidin were able to cross the stratum corneum and penetrate into the epidermis and dermis. An advantage of hesperidin penetration into the skin from the water over ethanol solution was observed (451.02 ± 14.50 vs. 357.39 ± 4.51 ng/cm2), as well as in the mangiferin study (127.56 ± 9.49 vs. 97.23 ± 2.92 ng/cm2). Furthermore, mangiferin penetration was more evident from nonfermented honeybush ethanol extract (189.85 ± 4.11 ng/cm2) than from solutions. The permeation of mangiferin and hesperidin through the skin to the acceptor fluid was observed regardless of whether the solution or the honeybush extract was applied. The highest ability to permeate the skin was demonstrated for the water solution of hesperidin (250.92 ± 16.01 ng/cm2), while the hesperidin occurring in the extracts permeated in a very low capacity. Mangiferin from nonfermented honeybush ethanol extract had the highest ability to permeate to the acceptor fluid within 24 h (152.36 ± 8.57 ng/cm2).

Potential of mucoadhesive chitosan glutamate microparticles as microbicide carriers - antiherpes activity and penetration behavior across the human vaginal epithelium.

Chitosan glutamate (gCS) spray-dried microparticles appear promising carriers to overcome challenges associated with vaginal microbicide delivery. This study aimed at elucidating the penetration and mucoadhesive behavior of developed gCS multiunit carriers with zidovudine (ZVD) as a model antiretroviral agent in contact with excised human vaginal epithelium followed with an examination of in vitro antiherpes activity in immortal human keratinocytes HaCaT and human vaginal epithelial cells VK2-E6/E7. Both ZVD dispersion and placebo microparticles served as controls. Microparticles displayed feasible (comparable to commercial vaginal product) mucoadhesive and mucoretention characteristics to isolated human vaginal tissue. Ex vivo penetration studies revealed that gCS increased the accumulation of active agent in the vaginal epithelium but surprisingly did not facilitate its penetration across human tissue. Finally, the obtained antiviral results demonstrated the potential of gCS as an antiherpes adjunctive, whose mode of action was related to blocking viral attachment.

Development of a Biphasic-Release Multiple-Unit Pellet System with Diclofenac Sodium Using Novel Calcium Phosphate-Based Starter Pellets.

Novel calcium phosphate-based starter pellets were used to develop a biphasic-release multiple-unit pellet system (MUPS) with diclofenac sodium as a model drug in the form of hard gelatin capsules. For comparative purposes, corresponding formulations based on the inert cores made of microcrystalline cellulose, sucrose and isomalt were prepared. The developed system consisted of two types of drug-layered pellets attaining different release patterns: delayed-release (enteric-coated) and extended-release. Dissolution characteristics were examined using both compendial and biorelevant methods, which reflected fed and fasting conditions. The results were collated with an equivalent commercial product but prepared with the direct pelletization technique.

Transdermal transport of collagen and hyaluronic acid using water in oil microemulsion.

Collagen and hyaluronic acid (HA) are biopolymers that affect the appearance and condition of the skin. Delivery of these compounds into the skin is highly challenging since have a number of disadvantageous properties, such as high molecular weight and hydrophilicity. Here, we evaluated the transdermal penetration of low and high molecular weight collagen and HA from microemulsions. A number of microemulsion formulations, differing in the content of polymers and surfactants (i.e. penetration promoters), were used for the permeation study. In addition, a correlation was made between the composition of these microemulsions and the polymers transport efficiency. The results indicate that, microemulsions enable transdermal permeation of collagen and HA. The concentration of polymers and the solubilization capacity of microemulsions had the greatest influence on the permeation. Surprisingly, the molecular weight of polymers and the content of other components affected the size of microemulsion particles, and thus these parameters had an indirect influence on the permeation process. This study demonstrated therefore the potential therapeutic use of microemulsion with collagen and HA in improving and regenerating the barrier of aged or diseased skin.

The consequences of overcoming the human skin barrier by siloxanes (silicones) Part 1. Penetration and permeation depth study of cyclic methyl siloxanes.

Dynamic production of cyclic siloxanes: octamethylcyclotetrasiloxane D4, decamethylcyclopentasiloxane D5 and dodecamethylcyclohexasiloxane D6 increases their concentrations in environment. It is considered that both environmental pollution and the usage of personal care products and cosmetics containing cyclic siloxanes can be the main source of the human exposure by transdermal route. The aim of the study was to verify the possibility to overcome the skin barrier by cyclic siloxanes (ATR-FTIR and GC-FID), evaluation of diffusion pathway to stratum corneum SC (Fluorescence microscopy), and determination of depth of permeation to deeper skin layers: epidermis and dermis (ATR-FTIR) and also of potential interaction with SC lipids and proteins (Fluorescence microscopy, ATR-FTIR) and the cytotoxicity studies against HaCaT cells (MTT test). The results show that D4, D5 and D5 can penetrate to SC and permeate into the deeper layers of the skin: epidermis and dermis. The quantitative analysis (GC-FID) showed that total cumulative doses for D4, D5 and D6 were: 42.50; 95.37 and 77.19 µg/cm2/24 h, respectively. The microscopic analysis proved, transepidermal route through the lipid matrix as well as through the canyons (intercluster spaces) were a diffusion pathway to the SC as well as disruption of human SC lipid structure by: D4 (the most), D5 and D6 (the least). The cytotoxicity studies demonstrated that the tested range of concentrations of D5 and D6 (up to 300 mM, 111 300 mg and 133 500 mg respectively) did not impaired the HaCaT growth, while D4 had IC50 value of 40 098 mM ±â€¯7.94 (10 906 ±â€¯872,5 mg).

Dissolution studies of metamizole sodium and pseudoephedrine sulphate dosage forms - comparison and correlation of electronic tongue results with reference studies.

This work reports a critical evaluation of the results of the release of active substances (APIs) from novel pharmaceutical formulations provided by an electronic tongue system (ET). Detailed dissolution studies of modified-release granules used in pharmacotherapy containing metamizole sodium and pseudoephedrine sulphate were carried out. The impact of the dissolution-modifying excipients (carmellose sodium and hypromellose) on the dissolution process as well as on the outcomes of the sensor array of ion-selective electrodes was investigated. The obtained dissolution profiles were compared and correlated with those registered during the reference studies performed according to the pharmacopoeial method. It was pointed out that the proper evaluation of the efficiency of the release modification requires the examination of dosage forms as well as physical mixtures of API and excipient. Moreover, the results obtained using potentiometric ET were complementary to the classical methodology. Their partial inconsistency, remarked during several experiments, should be interpreted with caution owing to simultaneous sensing of APIs and excipients by the sensors and their various performances (i.e. selectivity and sensitivity) towards these components.

The effect of mangiferin on skin: Penetration, permeation and inhibition of ECM enzymes.

Mangiferin (2-C-ß-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone) is a polyphenol with strong antioxidant properties. Mangiferin is obtained from the mango tree (Mangifera indica L., Anacardiaceae). It has been proven that mangiferin exhibits many pharmacological activities. The aim of this study was to analyze the penetration of mangiferin into the human skin and through the skin. According to our knowledge, skin penetration and permeation studies of mangiferin have not been analyzed so far. Additionally, the influence of mangiferin on two Extracellular Matrix Enzymes (ECM): collagenase and elastase, was evaluated for the first time. It has been indicated that mangiferin is able to permeate the stratum corneum and penetrate into the epidermis and dermis in comparable amounts. For confirmation of the obtained results, fluorescence microscopy was successfully utilized. The analysis revealed the capability of mangiferin to reversibly inhibit elastase and collagenase activity. The mechanism of mangiferin interaction with both enzymes was estimated as a noncompetitive inhibition.

Influence of dissolution-modifying excipients in various pharmaceutical formulations on electronic tongue results.

The overall performance of a potentiometric electronic tongue (ET) as well as the sensitivity and selectivity pattern of particular ion-selective electrodes forming the array towards exemplary APIs (metamizole sodium, pseudoephedrine sulphate) and excipients (hypromellose, carmellose, Eudragit E) was determined. Simultaneous sensing of both API and the encapsulating excipient in their physical mixture was noticed using potentiometric sensors. Usually, such altering of chemical image is treated as an evidence of taste masking/modified release effect (linked with chemical entrapment of API in polymer matrix), while the observed "mixture effect" can also take place which may complicate the interpretation of ET results. Moreover, the influence of the same excipients on chemical images of various APIs was compared and related to sensor array performance. The presented considerations should be taken into account in the case of ET assessment of drug dissolution profiles and detection of modified release effect, especially when novel drug delivery systems are considered.

The effect of a lipid composition and a surfactant on the characteristics of the solid lipid microspheres and nanospheres (SLM and SLN).

Solid lipid microparticles (SLM) were produced by a two-step process that, firstly, involved the emulsification of the molten lipid phase in a heated aqueous phase and, secondly, the system cooling. Compritol 888 ATO and Precirol ATO 5, including their mixtures with Miglyol 812 or Witepsol H15 were used as lipid components (10-30% w/w). The average size of the SLM prepared with Compritol and Tween 80 as an emulsifier was 3-7µm and the influence of lipid concentration and thermal sterilization was not large. Dispersions of SLM with Precirol (10-20% w/w) gellified upon storage. SLM stabilized with another surfactant, Tego Care 450, were larger in size and measured 40µm on average. The use of the sonication step (5-15min) in hot formulations containing 5% w/w of Compritol resulted in the formation of the solid lipid nanoparticles (SLN) with average size 200-300nm. The smallest SLN size (below 100nm on average) was obtained in SLN that contained Tego Care and an antimicrobial agent Euxyl PE 9010; such combination evoked synergism between the surfactant and Euxyl components.

Roxithromycin-loaded lipid nanoparticles for follicular targeting.

Particulate drug carriers e.g. nanoparticles (NPs) have been shown to penetrate and accumulate preferentially in skin hair follicles creating high local concentration of a drug. In order to develop such a follicle targeting system we obtained and characterized solid lipid nanoparticles (SLN) loaded with roxithromycin (ROX). The mean particle size (172±2 nm), polydisperisty index (0.237±0.007), zeta potential (-31.68±3.10 mV) and incorporation efficiency (82.1±3.0%) were measured. The long term stability of ROX-loaded SLN suspensions was proved up to 26 weeks. In vitro drug release study was performed using apparatus 4 dialysis adapters. Skin irritation test conducted using the EpiDerm™ tissue model demonstrated no irritation potential for ROX-loaded SLN. Ex vivo human skin penetration studies, employing rhodamine B hexyl ester perchlorate (RBHE) as a fluorescent dye to label the particles, revealed fluorescence deep in the skin, specifically around the hair follicles up to over 1mm depth. The comparison of fluorescence intensities after application of RBHE solution and RBHE-labelled ROX-loaded SLN was done. Then cyanoacrylate follicular biopsies were obtained in vivo and analyzed for ROX content, proving the possibility of penetration to human pilosebaceous units and delivering ROX by using SLN with the size below 200 nm.

The improvement of the dissolution rate of ziprasidone free base from solid oral formulations.

This work aims at increasing solubility and dissolution rate of ziprasidone free base-Biopharmaceutics Classifaction System (BCS) class II compound. The authors describe a practical approach to amorphization and highlight problems that may occur during the development of formulations containing amorphous ziprasidone, which was obtained by grinding in high-energy planetary ball mills or cryogenic mills. The release of ziprasidone free base from the developed formulations was compared to the reference drug product containing crystalline ziprasidone hydrochloride-Zeldox® hard gelatin capsules. All preparations were investigated using compendial tests (USP apparatuses II and IV) as well as novel, biorelevant dissolution tests. The novel test methods simulate additional elements of mechanical and hydrodynamic stresses, which have an impact on solid oral dosage forms, especially during gastric emptying. This step may prove to be particularly important for many formulations of BCS class II drugs that are often characterized by narrow absorption window, such as ziprasidone. The dissolution rate of the developed ziprasidone free base preparations was found to be comparable or even higher than in the case of the reference formulation containing ziprasidone hydrochloride, whose water solubility is about 400 times higher than its free base.

Polymeric nanoparticles-embedded organogel for roxithromycin delivery to hair follicles.

Drug delivery into hair follicles with the use of nanoparticles (NPs) is gaining more importance as drug-loaded NPs may accumulate in hair follicle openings. The aim was to develop and evaluate a pluronic lecithin organogel (PLO) with roxithromycin (ROX)-loaded NPs for follicular targeting. Polymeric NPs were evaluated in terms of particle shape, size, zeta potential, suspension stability, encapsulation efficiency and in vitro drug release. Lyophilized NPs were incorporated into the PLO and rheological measurements of the nanoparticles-embedded organogels were done. The fate of the NPs in the skin was traced by incorporation of a fluorescent dye into the NPs. As a result, ROX was efficiently incorporated into polymeric NPs characterized by the appropriate size (approximately 300 nm) allowing drug delivery to hair follicles. In ex vivo human skin penetration studies, horizontal skin sections revealed fluorescence deep in the hair follicles. Although the organogel has higher affinity to the lipidic follicular area than an aqueous suspension of NPs, it did not seem to improve penetration of the NPs along the hair shaft. The results proved that it was possible to achieve preferential targeting to the pilosebaceous unit using polymeric NPs formulated either into the aqueous suspension or semisolid topical formulation.

Determination of API content in a pilot-scale blending by near-infrared spectroscopy as a first step method to process line implementation.

Near infrared (NIR) spectroscopy was used for estimation of powder blend homogeneity and manufacturing control of a medicinal product powder mixture containing active pharmaceutical ingredient (API). Aiming at initiating a Process Analytical Technology (PAT) activity, the first step was a stationary mode at-line evaluation. In this, the content of pharmaceutical active compound in the powder mixtures intended to the direct tabletting was estimated based on recorded NIR spectra. Five formulations containing different quantities of API were prepared and analyzed also by a reference method--UV-Vis spectroscopy. A chemometric model was developed for calculation of the API amount in the mixtures. The Principal Component Regression (PCR) and Partial Least Squares (PLS) algorithms were used to obtain a model useful in further implementation for the PAT recommendations, into in-line blending control.

Development of rapid and robust stability-indicating method for analysis of ziprasidone (hydrochloride and freebase) as drug substance and in medicines by UPLC.

Ultra Performance Liquid Chromatography (UPLC) was employed to develop a rapid and robust method for the analysis of ziprasidone, both as a drug substance and in the final dosage forms. The application of this method in stability analyses was verified. Tests were carried out according to ICH/FDA guidelines, European Pharmacopeia, and United States Pharmacopeia rules, which take into account factors such as specificity, linearity, accuracy, and precision. Separation was performed on an Acquity UPLC BEH phenyl 1.7-microm column with a simple mobile phase, consisting of acetonitrile and water adjusted to pH 2.0 with ortho-phosphoric acid. Using this mobile phase and gradient elution, the separation was completed within 5 min. This method is very sensitive, and allows performing simultaneous identification, assay, and determination of impurities and related substances in one injection.

Taste masking of roxithromycin by spray drying technique.

The spray drying technique was used to obtain the roxithromycin containing microcapsules with high taste masking efficiency. Eudragit L30D-55 was chosen as a barrier coating. The taste was evaluated by an electronic tongue, and taste-masking effect in water lasted at least several dozen hours.