Development of cationic solid lipid nanoparticles incorporating cholesteryl-9-carboxynonanoate (9CCN) for delivery of antagomiRs to macrophages

Lipid-based nanoparticles are a useful tool for nucleic acids delivery and have been regarded as a promising approach for diverse diseases. However, off-targets effects are a matter of concern and some strategies to improve selectivity of solid lipid nanoparticles (SLNs) were reported. The goal of this study was to test formulations of SLNs incorporating lipid cholesteryl-9-carboxynonanoate (9CCN) as "eat-me" signal to target antagomiR oligonucleotides to macrophages. We formulate four SLNs, and those with a mean diameter of 200 nm and a Z-potential values between 25 and 40 mV, which allowed the antagomiR binding, were selected for in vitro studies. Cell viability, transfection efficiency and cellular uptake assays were performed within in vitro macrophages using flow cytometry and confocal imaging and the SLNs incorporating 25 mg of 9CCN proved to be the best formulation. Subsequently, we used a labeled antagomiR to study tissue distribution in in-vivo ApoE-/- model of atherosclerosis. Using the ApoE-/- model we demonstrated that SLNs with phagocytic signal 9-CCN target macrophages and release the antagomiR cargo in a selective way.

Methods for Developing a Process Design Space Using Retrospective Data

Prospectively planned designs of experiments (DoEs) offer a valuable approach to preventing collinearity issues that can result in statistical confusion, leading to misinterpretation and reducing the predictability of statistical models. However, it is also possible to develop models using historical data, provided that certain guidelines are followed to enhance and ensure proper statistical modeling. This article presents a methodology for constructing a design space using process data, while avoiding the common pitfalls associated with retrospective data analysis. For this study, data from a real wet granulation process were collected to pragmatically illustrate all the concepts and methods developed in this article.

Comparative Analysis of the Physicochemical and Biological Characteristics of Freeze-Dried PEGylated Cationic Solid Lipid Nanoparticles

Cationic solid-lipid nanoparticles (cSLNs) have become a promising tool for gene and RNA therapies. PEGylation (PEG) is crucial in enhancing particle stability and protection. We evaluated the impact of PEG on the physicochemical and biological characteristics of cholesteryl-oleate cSLNs (CO-cSLNs). Several parameters were analyzed, including the particle size, polydispersity index, zeta potential, shape, stability, cytotoxicity, and loading efficiency. Five different formulations with specific PEGs were developed and compared in both suspended and freeze-dried states. Small, homogeneous, and cationic suspended nanoparticles were obtained, with the Gelucire 50/13 (PEG-32 hydrogenated palm glycerides; Gelucire) and DSPE-mPEG2000 (1,2-distearoyl-phosphatidylethanolamine-methyl-polyethyleneglycol conjungate-2000; DSPE) formulations exhibiting the smallest particle size (~170 nm). Monodisperse populations of freeze-dried nanoparticles were also achieved, with particle sizes ranging from 200 to 300 nm and Z potential values of 30-35 mV. Notably, Gelucire again produced the smallest particle size (211.1 ± 22.4), while the DSPE and Myrj S100 (polyoxyethylene (100) stearate; PEG-100 Stearate) formulations had similar particle sizes to CO-cSLNs (~235 nm). The obtained PEGylated nanoparticles showed suitable properties: they were nontoxic, had acceptable morphology, were capable of forming SLNplexes, and were stable in both suspended and lyophilized states. These PEG-cSLNs are a potential resource for in vivo assays and have the advantage of employing cost-effective PEGs. Optimizing the lyophilization process and standardizing parameters are also recommended to maintain nanoparticle integrity.

Pellets and gummies: Seeking a 3D printed gastro-resistant omeprazole dosage for paediatric administration

The production of 3D printed pharmaceuticals has thrived in recent years, as it allows the generation of customised medications in small batches. This is particularly helpful for patients who need specific doses or formulations, such as children. Compounding pharmacies seek alternatives to conventional solid oral doses, opting for oral liquid formulations. However, ensuring quality and stability, especially for pH-sensitive APIs like omeprazole, remains a challenge. This paper presents the application of semi-solid extrusion 3D printing technology to develop patient-tailored medicinal gummies, with an eye-catching appearances, serving as an innovative omeprazole pharmaceutical form for paediatric use. The study compares 3D printing hydrogels with dissolved omeprazole to hydrogels loaded with gastro-resistant omeprazole pellets, a ground-breaking approach.. Gastro-resistance and dissolution profiles were studied using different methods for better comparison and to emphasize the significance of the assay's methodology. Both developed formulas exhibit proper rheology, good printability, and meet content and mass uniformity standards. However, the high gastro-resistance and suitable release profile of 3D printed chewable semi-solid doses with enteric pellets highlight this as an effective strategy to address the challenge of paediatric medication.

SeDeM as a Tool to Validate Drug Substance Manufacturing Processes and Assess Scalability and Suitability for Direct Compression: Supplier Screening

During the development of an oral solid form of a drug substance, a thorough understanding of the critical material attributes is necessary, as the physical properties of the active pharmaceutical ingredient (API) can profoundly influence the drug product's manufacturability, critical quality attributes, and bioavailability. The objective of this study was to validate the manufacturing process of the drug Linezolid from three different sources at both the pilot and industrial scale and to identify differences in critical material attributes between the API manufacturers. Furthermore, the scalability factor between the pilot and industrial scale and the suitability of a process for direct compression were also evaluated. In the present study, the different sources of API were characterized by SeDeM methodology, particle size distribution, and scanning electron microscopy determinations. The statistical analysis revealed that no statistically significant differences were found for any of the parameters under study for the same API source analyzed on both scales. On the other hand, for most of the parameters evaluated, statistical differences were observed between the different sources. It was concluded that SeDeM was able to successfully validate the API manufacturing process, assess scalability, and distinguish between sources. Therefore, it could be highly valuable in the formulation phase to select the best API source.

Improvement of the Pour Plate Method by Separate Sterilization of Agar and Other Medium Components and Reduction of the Agar Concentration

Although the pour plate method is widely employed in microbiological quality control, it has certain drawbacks, including having to melt the culture medium before seeding. In this study, the preparation of the culture medium was modified by using a lower concentration of agar (10 g/L), which was separated from the nutrients during sterilization. The new protocol was assessed in media frequently used in microbiological quality control of food, cosmetics, and pharmaceutical products, with tryptic soy agar (TSA), Sabouraud 4% dextrose agar (SDA), and violet red bile glucose agar (VRBG). In comparison with the conventionally produced media, the modifications significantly improved the growth of Saccharomyces cerevisiae in SDA, Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Typhimurium, and Candida albicans in TSA and Escherichia coli ATCC 8739 and ATCC 25922 and S. Typhimurium in VRBG. The modified VRBG was also more selective for Pseudomonas aeruginosa. Regarding physicochemical properties, a significantly lower pH was observed in TSA and VRBG and lower strength values in TSA. Sterilizing agar separately from the other components of the medium and reducing the agar concentration to 10 g/L can improve microorganism growth and enhance the selectivity of differential media in the pour plate method. These modifications could facilitate the automation of this culture technique. IMPORTANCE In the era of rapid microbiological methods, there is a need to improve long-established culture techniques. Drawbacks of the pour plate method include having to melt each medium separately before seeding. For this technique, we demonstrate that separating the agar from the other components of commonly used media during sterilization and reducing the agar concentration to 10 g/L can enhance microbial growth. The new protocol could have advantages in routine laboratory practice because less agar is required and the same molten agar suspension can be used to prepare different media. Moreover, these modifications could facilitate the automation of the pour plate method.

Development of a Standardized Method for Measuring Bioadhesion and Mucoadhesion That Is Applicable to Various Pharmaceutical Dosage Forms

Although some methods for measuring bioadhesion/mucoadhesion have been proposed, a standardized method is not yet available. This is expected to hinder systematic comparisons of results across studies. This study aimed to design a single/systematic in vitro method for measuring bioadhesion/mucoadhesion that is applicable to various pharmaceutical dosage forms. To this end, we measured the peak force and work of adhesion of minitablets, pellets, and a bioadhesive emulsion using a texture analyzer. Porcine tissue was used to simulate human stomach/skin conditions. The results of these formulations were then compared to those for formulations without the bioadhesive product. We conducted a case study to assess the stability of a bioadhesive emulsion. The results for the two parameters assessed were contact time = 60 s and contact force = 0.5 N at a detachment speed of 0.1 mm/s. Significant differences were observed between the bioadhesive and control formulations, thus demonstrating the adhesive capacity of the bioadhesive formulations. In this way, a systematic method for assessing the bioadhesive capacity of pharmaceutical dosage forms was developed. The method proposed here may enable comparisons of results across studies, i.e., results obtained using the same and different pharmaceutical formulations (in terms of their bioadhesion/mucoadhesion capacity). This method may also facilitate the selection of potentially suitable formulations and adhesive products (in terms of bioadhesive properties).

Improvement of Mueller-Kauffman Tetrathionate-Novobiocin (MKTTn) enrichment medium for the detection of Salmonella enterica by the addition of ex situ-generated tetrathionate

The detection of Salmonella in food is based on the use of a selective enrichment broth such as Muller-Kauffman Tetrathionate-Novobiocin (MKTTn), in which tetrathionate plays a key role by providing Salmonella with a growth advantage. As sodium tetrathionate is unstable, it is generated in situ by the addition of iodine (Lugol's solution) before seeding. This step is cumbersome as the solution is easily spilled, compromising the performance of the medium and hindering the work of technicians. The aim of this study was to optimize MKTTn broth by generating tetrathionate ex situ through an external reaction between iodine and thiosulphate followed by lyophilization. Quality control procedures were performed to compare the modified and original media, testing pure productivity (enrichment with 50-120 CFU of Salmonella Thyphimurim ATCC 14028 and Salmonella Enteritidis ATCC 13076 and plating on Xylose Lysine Deoxycholate agar, XLD), mixed productivity (50-120 CFU of Salmonella strains and Pseudomonas aeruginosa and Escherichia coli at ≥10⁴ CFU and XLD plating) and selectivity (≥10⁴ CFU of P. aeruginosa and Enterococcus faecalis and plating on Tryptone Casein Soy agar, TSA). The modified MKTTn medium (S/L) performed comparably with the original medium in terms of growth of both Salmonella strains (>300 colonies in XLD), alone or with P. aeruginosa and E. coli. Quantitative assays showed no statistically significant differences in the number of colonies grown on XLD after 10^-5 dilution (p = 0.7015 with S. Thyphimurim ATCC 14028 and p = 0.2387 with S. enteritidis ATCC 13076; ANOVA test). MKTTn medium (S/L) was also selective against E. coli (≤100 colonies) and E. faecalis (<10 colonies). These results suggest that adding tetrathionate as a lyophilisate (S/L) is a feasible alternative to the use of Lugol's solution for the preparation of MKTTn enrichment broth and does not affect the properties of the medium.

Robustness Optimization of an Existing Tablet Coating Process Applying Retrospective Knowledge (rQbD) and Validation

The objective of these studies is to verify and validate the improvement in the inter-tablet coating uniformity for an industrially commercialized coated tablet, without involving changes in the approved registration dossier. Using the CPP (critical process parameters) determined from previous retrospective statistical analysis, the recommended working ranges are identified. Retrospective analysis showed that the design of experiments (DoE) provided an improved process variable configuration. Therefore, it is decided to study two critical parameters: Product temperature and drum speed, with an additional 2² experimental design. The quality results of the samples analyzed show that the aesthetic defects of the batches made with the new working ranges have been reduced. These results have also been corroborated with the 42 industrial batches manufactured with the new ranges. With the optimized parameters, tablets have been coated and the suitability of the model determined. The results demonstrated the overall reliability and effectiveness of the proposed Quality by Design approach and provides a useful tool to help optimize the industrial coating process. This study confirms that it is possible to optimize and validate the manufacturing process of an existing commercial product by means of a DoE with retrospective data. Therefore, no variation in the dossier is required.

Formulation of Sustained Release Hydrophilic Matrix Tablets of Tolcapone with the Application of Sedem Diagram: Influence of Tolcapone's Particle Size on Sustained Release

Hydrophilic matrix tablets are a type of sustained release dosage form characterized by distributing a drug in a matrix that is usually polymeric. Tolcapone is a drug that inhibits the enzyme catechol-O-methyl transferase. In recent years, it has been shown that tolcapone is a potent inhibitor of the amyloid aggregation process of the transthyretin protein, and acts by stabilizing the structure of the protein, reducing the progression of familial amyloid polyneuropathy. The main objective of this study was to obtain a sustained release tablet of tolcapone for oral administration with a preferred dosage regimen of 1 administration every 12 or 24 h and manufactured, preferably, by direct compression. The SeDeM Diagram method has been used for the formulation development of hydrophilic matrix tablets. Given the characteristics of tolcapone, the excipient selected for the formation of the polymeric matrix was a high viscosity hydroxypropylmethylcellulose (Methocel^® K100M CR). A decrease in the particle size of tolcapone resulted in a slower dissolution release of the formulation when the concentration of the polymer Methocel^® K100M CR was below 29%. These surprising and novel results have given rise to patent number WO/2018/019997.

Study of tocopherol content and its potential antioxidant activity in commercial lipid emulsions for parenteral nutrition

The objective of this study was to determine the content and evaluate the potential antioxidant effect of tocopherols in commercially available lipid emulsions, using a simple validated method adequate for further routine use. During the study, variability between manufacturers as well as between three non-consecutive batches of the same emulsion was observed. Furthermore, addition of α-tocopherol to lipid emulsions as excipient yields more stable emulsions and potentially a beneficial clinical effect. It was concluded that the variation of the tocopherol content between batches implies the importance of control and specification of tocopherol content by the manufacturers.

Therapeutic potential of nicotinamide adenine dinucleotide (NAD)

Nicotinamide adenine nucleotide (NAD) is a small ubiquitous hydrophilic cofactor that participates in several aspects of cellular metabolism. As a coenzyme it has an essential role in the regulation of energetic metabolism, but it is also a cosubstrate for enzymes that regulate fundamental biological processes such as transcriptional regulation, signaling and DNA repairing among others. The fluctuation and oxidative state of NAD levels regulate the activity of these enzymes, which is translated into marked effects on cellular function. While alterations in NAD homeostasis are a common feature of different conditions and age-associated diseases, in general, increased NAD levels have been associated with beneficial health effects. Due to its therapeutic potential, the interest in this molecule has been renewed, and the regulation of NAD metabolism has become an attractive target for drug discovery. In fact, different approaches to replenish or increase NAD levels have been tested, including enhancement of biosynthesis and inhibition of NAD breakdown. Despite further research is needed, this review provides an overview and update on NAD metabolism, including the therapeutic potential of its regulation, as well as pharmacokinetics, safety, precautions and formulation challenges of NAD supplementation.

Development and Validation of a New High-Performance Liquid Chromatography Method for the Simultaneous Quantification of Coenzyme Q10, Phosphatidylserine, and Vitamin C from a Cutting-Edge Liposomal Vehiculization

A high-performance liquid chromatography (HPLC) method was developed to simultaneously quantify three widely used active substances such as coenzyme Q10, phosphatidylserine, and vitamin C. This new method optimizes current timing and costs in the analyses of these three active substances. Additionally, since the analyzed compounds were encapsulated on a cutting-edge liposomal formulation, further processing was necessary to be developed prior to HPLC analyses. The technique was studied and adequately validated in accordance with the guidelines of the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) regarding selectivity, linearity, accuracy, precision, and robustness. After data treatment of results, linear regressions for all active substances showed an optimal linearity with a correlation coefficient of >0.999 in the concentration range between 70 to 130% of the liposomal formulation and less than a 3% relative standard deviation (RSD) in accuracy and precision.

Formulation of Direct Compression Zidovudine Tablets to Correlate the SeDeM Diagram Expert System and the Rotary Press Simulator Styl'ONE Results

The SeDeM diagram expert system has been applied to study Zidovudine and some excipients. From the obtained diagrams, a pharmaceutical formula has been designed. SeDeM diagram ascertains the critical parameters that are suitable for a direct compression. The formula is compressed using a rotary tablet press simulator which emulates rotary tablet press' compression profiles. From these compressions, we study the formula behavior under different industrial production conditions but saving a huge amount of material. The study is done at different compression forces and compression speeds and taking into account the influence of the pre-compression force. The differences observed between the compression profiles are hereby described. The results indicate that the formulation is able to be compressed adequately with the emulated compression profiles and no differences are observed between the final products. Therefore, we can assure that the SeDeM diagram expert system is accurate and robust. Moreover, its results are comparable with the compression results in a rotary tablet press, which has never been described in the pharmaceutical literature before. From the obtained results, it is possible to select the best rotary press to scale-up this formulation.

Optimization of the Cohesion Index in the SeDeM Diagram Expert System and application of SeDeM Diagram: An improved methodology to determine the Cohesion Index

In this study, we suggest optimizing the methodology to determine the Cohesion Index (Icd) in order to avoid mistaken characterizations due to powder bulk density. For this purpose, five different excipients, with different bulk densities and of different chemical nature, were compressed at different heights. Their compression and their tablet characterization enable establishing a powder weight for compression in accordance with its bulk density. Therefore, the resulting tablet will have a height within a defined range of heights where it has no critical effects on its hardness. Then, the impact of this optimization is shown in a formula development, one of the main SeDeM's applications. A mathematical equation was used to calculate the theoretical amount of excipient to formulate the API according to both methodologies. The compression results demonstrate that the characterization with the NM-Icd is more accurate than the previous one while preserving its simplicity.

A new design for the review and appraisal of semi-solid dosage forms: Semi-solid Control Diagram (SSCD)

The Semi-solid Control Diagram (SSCD) is a new tool designed for the study of different excipients and different semi-solid dosage forms. It can be used to review and evaluate different formulations and/or batches and facilitate the selection of one of them that will present the most suitable galenic characteristics for topical application. It is also useful to track stability studies by comparing the diagrams, which allows to measure the impact of subjecting the formulation to different conditions and times to be examined. In this study, the Semi-solid Control Diagram (SSCD) is used as an instrument for studying and evaluating semi-solid pharmaceutical dosage forms, by comparing several different semisolid preparations (lipogels). With these results, the tool is validated and the best formulation has been discriminated from the others.

Osmolality predictive models of different polymers as tools in parenteral and ophthalmic formulation development

During the development of parenteral dosage forms, different physicochemical studies are required to ensure stable, effective and safe formulations. The osmolality of this kind of dosage forms should bear a close similarity to the body fluids to prevent local irritation, pain or even more significant side effects like endothelial damage. The osmotic studies performed in Polyethylene glycol 400 (PEG 400), Polyethylene glycol 4000 (PEG 4000), Poloxamer 407 (P407), Sodium Hyaluronate (SH), Chondroitin Sulphate Sodium (CS), Cremophor RH 40 (CRE40) and Polyvinyl alcohol (PVA) aqueous solutions, showed that the theoretical determination of the osmolality based on their molecular weight as the only determinant factor did not agree with the values obtained by the measurement of colligative properties such as the freezing point depression. The data obtained from this study and its analysis, provided predictive equations that can be used as tools in the primary development to estimate formulation's osmolality at different concentrations; and its evolution over a period at the hypothetical worst-case scenario of storage temperature.

Cholesteryl oleate-loaded cationic solid lipid nanoparticles as carriers for efficient gene-silencing therapy

Background

Cationic solid lipid nanoparticles (SLNs) have been given considerable attention for therapeutic nucleic acid delivery owing to their advantages over viral and other nanoparticle delivery systems. However, poor delivery efficiency and complex formulations hinder the clinical translation of SLNs.

Aim

The aim of this study was to formulate and characterize SLNs incorporating the cholesterol derivative cholesteryl oleate to produce SLN–nucleic acid complexes with reduced cytotoxicity and more efficient cellular uptake.

Methods

Five cholesteryl oleate-containing formulations were prepared. Laser diffraction and laser Doppler microelectrophoresis were used to evaluate particle size and zeta potential, respectively. Nanoparticle morphology was analyzed using electron microscopy. Cytotoxicity and cellular uptake of lipoplexes were evaluated using flow cytometry and fluorescence microscopy. The gene inhibition capacity of the lipoplexes was assessed using siRNAs to block constitutive luciferase expression.

Results

We obtained nanoparticles with a mean diameter of approximately 150–200 nm in size and zeta potential values of 25–40 mV. SLN formulations with intermediate concentrations of cholesteryl oleate exhibited good stability and spherical structures with no aggregation. No cell toxicity of any reference SLN was observed. Finally, cellular uptake experiments with DNA-and RNA-SLNs were performed to select one reference with superior transient transfection efficiency that significantly decreased gene activity upon siRNA complexation.

Conclusion

The results indicate that cholesteryl oleate-loaded SLNs are a safe and effective platform for nonviral nucleic acid delivery.

Quality and integrity of data in research, development, and innovation: a risk analysis method applied to laboratory notebooks in a university pilot plant

Risk analysis tools can be applied in the early stages of the research, development, and innovation of pharmaceutical drugs. We used a risk ranking and filtering method to optimize time resources in internal audits of project development documents in order to ensure traceability in a university pilot plant. Data gathered during audits undertaken over a 14 month period were classified according to risk factors at several levels. Consequently, time resources for this type of internal audit can be optimised by focusing on aspects that are objectively determined to be critical to traceability. In addition, quality can be ensured by paying more attention to the most critical aspects, rather than the most commonly observed findings in historical data.

LAY ABSTRACT

One of the most important issue for a research, development, and innovation centre is the traceability of both experimental tasks and their documentation. This study describes an analysis of the findings revealed during internal audits carried out over a 14 month period, in order to establish its criticality and to highlight those important aspects to consider in future audits, while saving both personnel and time resources to carry out internal audits on development of projects.

Improving tablet coating robustness by selecting critical process parameters from retrospective data

CONTEXT

Although tablet coating processes are widely used in the pharmaceutical industry, they often lack adequate robustness. Up-scaling can be challenging as minor changes in parameters can lead to varying quality results.

OBJECTIVE

To select critical process parameters (CPP) using retrospective data of a commercial product and to establish a design of experiments (DoE) that would improve the robustness of the coating process.

MATERIALS AND METHODS

A retrospective analysis of data from 36 commercial batches. Batches were selected based on the quality results generated during batch release, some of which revealed quality deviations concerning the appearance of the coated tablets. The product is already marketed and belongs to the portfolio of a multinational pharmaceutical company.

RESULTS

The Statgraphics 5.1 software was used for data processing to determine critical process parameters in order to propose new working ranges.

DISCUSSION AND CONCLUSIONS

This study confirms that it is possible to determine the critical process parameters and create design spaces based on retrospective data of commercial batches. This type of analysis is thus converted into a tool to optimize the robustness of existing processes. Our results show that a design space can be established with minimum investment in experiments, since current commercial batch data are processed statistically.

SeDeM expert system a new innovator tool to develop pharmaceutical forms

CONTEXT

The SeDeM expert system is based on the experimental study and quantitative determination of the characterization parameters of powdered substances, the aim being to determine whether a substance is suitable for producing tablets by means of direct compression (DC) technology, thereby reducing the lead time for pre-formulation studies. Additionally, this expert system also provides formulations with a minimum number of excipients.

OBJECTIVE

We used this system to analyze suitable formulas for the production of orodispersible ibuprofen tablets.

METHOD

Twenty-one disintegrants and ibuprophen were characterized using SeDeM methodology.

RESULTS

The results indicated that production of ibuprofen tablets by DC would require improvements in the dimension and compressibility factors of the active pharmaceutical ingredient. The expert system analysis provided the specific percentage of disintegrant needed to blend with ibuprofen and a standardized formula of lubricants in order to obtain a powder mix that would successfully produce tablets by DC. The eight formulas proposed by SeDeM were produced and tested in the laboratory.

CONCLUSION

All eight formulas successfully produced tablets by DC, but only four of them could be considered suitable for use as an orodispersible tablet and accomplishes all the pharmaceutical quality parameters. So, in fact, the use of the SeDeM system reduced the time of medicine's development and therefore the cost of the activity.

Total organic carbon (VCSN and VWP) and HPLC analysis for cleaning validation in a pharmaceutical pilot plant

This paper presents a useful method using total organic carbon analyzers employing both combustion and wet oxidation for validating equipment cleaning procedures and verifying cleaning in a pharmaceutical pilot plant. The results are compared with those obtained using high-performance liquid chromatography. The study summarizes the initial steps that should be taken into account and focuses particularly on the solutions to some of the most critical considerations (e.g., glass material, detection and quantification limits, recovery). Also described are the calculation of control limits and the good results obtained.

Method for the development of topical medicinal aerosols using liquified hydrocarbon gas

Low chain liquid hydrocarbons (LH) at room temperature and atmospheric pressure can be used to simulate the effect of gas hydrocarbons (GH) in aerosol systems without the need of using pressured flasks. Samples of different tetracycline formulations were tested with LH and GH in order to study their behaviour and physicochemical stability in the system. The results showed a similar behaviour between samples when LH or GH were used, suggesting the use of LH to simulate the effect of GH introduction in the system, as a useful predictive method for the development of pressured aerosol formulations without using pressured containers in early steps of the process, such as pre-formulation studies.

Application of a validated method in the stability study of colistin sulfate and methylparaben in a veterinary suspension formulation by high-performance liquid chromatography with a diode array detector

A methodology following International Cooperation on Harmonization for Veterinary Products (VICH) guidelines for the stability evaluation of colistin sulfate in a nonaqueous suspension pharmaceutical dosage form for veterinary use (via their drinking water) is described. This method monitors the percentage of colistin sulfate during the stability study of the preparation in drinking water and establishes the shelf life of the final product by a new high-performance liquid chromatography method which was developed and validated for the simultaneous determination of colistin sulfate [colistin A (Polymixin E1) and colistin B (Polymixin E2)] and methylparaben (Nipagin) using a diode array detector (DAD). The method uses a Kromasil C18 column and isocratic elution. The mobile phase consisted of an acetonitrile-sodium sulfate anhydrous solution (25 + 75) pumped at a flow rate of 1.5 mL/min. The DAD was set at 215 nm. The validation study was carried out according to the VICH guidelines in order to prove that the new analytical method meets the reliability characteristics, which include the fundamental criteria for validation: selectivity, linearity, precision, accuracy, and sensitivity. The method was applied during the quality control or stability studies of the suspension dosage form in order to quantify the drug (colistin) and preservative, and proved to be suitable for rapid and reliable quality control.

Stability evaluation of amoxicillin in a solid premix veterinary formulation by monitoring the degradation products through a new HPLC analytical method

A methodology (by VICH guidelines) for the stability evaluation of amoxicillin in granular premixes is described. This method is based on the monitoring of the degradation products formed during the stability study by a new HPLC-RP method, which has been developed and validated for the simultaneous determination of amoxicillin and its degradation products. The method uses a Nucleosil 120 C18 column and gradient elution. The mobile phase consisted of a mixture of methanol and buffer solution pH 3+/-0.05 at different proportion according to a time-schedule programme, pumped at a flow rate of 1.750 ml min(-1). The DAD detector was set at 230 nm. The validation study was carried out fulfilling the VICH guidelines in order to prove that the new analytical method, meets the reliability characteristics, and these characteristics showed the capacity of analytical method to keep, throughout the time, the fundamental criteria for validation: selectivity, linearity, precision, accuracy, sensitivity (LOD, LOQ) and robustness. The method was applied during the stability study of an amoxicillin premix in order to quantify the drug (amoxicillin) and all its degradation products to evaluate the shelf life of the new veterinary dosage form. The method also proved to be suitable as a rapid and reliable quality control method.

A new expert systems (SeDeM diagram) for control batch powder formulation and preformulation drug products

The new SeDeM Method is proposed for testing the batch-to-batch reproducibility of the same active pharmaceutical ingredient (API) in powder form. The procedure describes the study of the galenic properties of substances in powder form in terms of the applicability of direct compression technology. Through experimental determination of the SeDeM Method parameters, and their subsequent mathematical treatment and graphical expression (SeDeM Diagram), three batches of the same API were analysed to determine whether it was suitable for direct compression. Batch-to-batch reproducibility of the results was verified. It was concluded that the SeDeM Method is suitable for testing batch-to-batch reproducibility of characteristics in powdered APIs substances. The results obtained confirm that the SeDeM Method is a useful, effective tool for drug-preformulation studies providing the pharmacotechnical data required when formulating a drug in tablet form. In addition, the results were effective for defining the most appropriate manufacturing technology.

A new validated method for the simultaneous determination of benzocaine, propylparaben and benzyl alcohol in a bioadhesive gel by HPLC

A new HPLC-RP method has been developed and validated for the simultaneous determination of benzocaine, two preservatives (propylparaben (nipasol) and benzyl alcohol) and degradation products of benzocaine in a semisolid pharmaceutical dosage form (benzocaine gel). The method uses a Nucleosil 120 C18 column and gradient elution. The mobile phase consisted of a mixture of methanol and glacial acetic acid (10%, v/v) at different proportion according to a time-schedule programme, pumped at a flow rate of 2.0 ml min(-1). The DAD detector was set at 258 nm. The validation study was carried out fulfilling the ICH guidelines in order to prove that the new analytical method, meets the reliability characteristics, and these characteristics showed the capacity of analytical method to keep, throughout the time, the fundamental criteria for validation: selectivity, linearity, precision, accuracy and sensitivity. The method was applied during the quality control of benzocaine gel in order to quantify the drug (benzocaine), preservatives and degraded products and proved to be suitable for rapid and reliable quality control method.

Development and validation of a new HPLC analytical method for the determination of alprazolam in tablets

A new analytical method is developed together with its latter validation study, by means of a high resolution liquid chromatography (HPLC) of reverse phase to quantify alprazolam (8-chloro-1-methyl-6-phenyl-4H-[1,2,4] triazole [4,3,-alpha]-[1,4] benzodiazepine) in tablets. Determination is carried out by means of an ODS C18 column (200 mm x 4.6 mm i.d., 5 microm particle size); the mobile phase consisted of a mixture of 0.02 M buffer solution of phosphates (pH 6.0) and acetonitrile (45:55, v/v). It is pumped through the chromatographic system at a flow rate of 0.50 ml min(-1). The UV detector is operated at 254 nm. The validation study is carried out fulfilling the ICH guidelines in order to prove that the new analytical method, meets the reliability characteristics, and these characteristics show the capacity of an analytical method to keep, throughout the time, the fundamental criteria for validation: selectivity, linearity, precision, accuracy and sensitivity. The method is applied during the working day for the quality control of commercial alprazolam tablets in order to quantify the drug and its degradation products and to check the content uniformity test.

Study of formulation parameters by factorial design in metoprolol tartrate matrix systems

The study of formulation parameters in hydrophilic matrices of metoprolol tartrate by 2(3) factorial design wass made. We compared the dissolution profiles of two hydrophilic polymers (hydroxypropylmethylcellulose and hydroxyethylcellulose) at high and low concentrations and in the presence or absence of an insoluble excipient (calcium hydrogen phosphate dihydrate). The results showed that the presence of an insoluble excipient influenced almost all of the dissolution parameters.