At Sirius Analytical we design and manufacture highly automated instruments to measure physicochemical parameters - pKa, logP & logD, solubility and dissolution. We also operate as a CRO providing a wide range of physical chemistry analytical services.
Overview
From 1997 to 2008 GLpKa was Sirius' industry leading instrument for pKa, logP/D and solubility measurement using pH-metric technology. GLpKa has five dispenser units that deliver all necessary reagents automatically. It uses a proprietary Ag/AgCI double junction electrode for accurate pH measurement. An overhead stirrer ensures that the correct level of mixing is used for each type of assay. Temperature control is achieved using an external re-circulating water bath whilst assay temperature is monitored by a PT100 probe. Assays are designed, controlled and processed with our RefinementPro2 software.
In pH-metric methods, pKa is measured by titrating a solution of the sample in water or solvent with acid and base, and calculating the pKa from the shape of the titration curve. This method will always find the pKas of a sample, and easily copes with multiple and overlapping pKas.
LogP is also measured by a pH-metric method, based on a two-phase acid-base titration in a mixture of water and octanol. The assay delivers logP results for the neutral and ion-pair species and a pH vs. logD profile. The method works well for poorly water-soluble samples, because they tend to dissolve in the octanol phase.
Overview
Advanced UV pKa measurement on GLpKa and PCA200
D-PAS is an accessory for Sirius' GLpKa and PCA200 instruments. With D-PAS, the multiwavelength UV spectrum is measured while the sample is titrated, and pKa is determined by RefinementPro software from the changes in UV absorption that occur as a function of pH whilst the molecule undergoes ionization. This pH-UV method for pKa measurement is preferred by most customers because it's faster than pH-metric pKa measurement, works at much lower concentration (very helpful for poorly soluble compounds), and also because the calculation of results from the data is faster and much easier to perform.
Overview
Low cost auto titrator for entry level automation of pKa, logP/D, Solubility and Dissolution measurement
PCA200 was a semi-automated instrument for high-quality measurement - Ideal for laboratories with a low sample throughput, or for academic research applications.
pKa is measured by automated potentiometric titration. LogP is also measured by a potentiometic method, based on a two-phase acid- base titration in a mixture of water and octanol.
Overview
For accurate and automated measurement of pH in a wide range of samples
GLpH automates all the actions of pH measurement to create the world's most accurate pH meter. The electrode, stirrer and temperature probe are moved automatically between calibration buffer solutions, three wash solutions and the sample. All the errors associated with manual pH measurement are eliminated. The accuracy and repeatability are outstanding.
Sirius GLpH is used in Quality Control laboratories and process monitoring from petrochemicals to personal care. GLP protocols are built-in. Calibration can be pre-programmed to take place at user-defined intervals, so GLpH is always calibrated and ready to go.
Overview
Automated measurement of pH and Titratable Acidity(TA) of wine and juice.
Sirius Vinotrate wine titrator is dedicated to measurement of pH and Titratable Acidity (TA) of wine and juice. It uses automation to ensure high quality performance for these two measurements.
Vinotrate was developed in consultation with leading wine laboratories and incorporates features like CO2 removal, flowing water wash and non-blocking reference electrode to ensure reproducibility and high quality results - time and time again.
Vinotrate sales in California and US west coast are handled by our distributor Alpine Scientific.
Overview
RefinementPro 2 software controls GLpKa, PCA200 and D-PAS instruments and calculates pKa and logP results from the experimental data. RefinementPro 2 improves and enhances the ground-breaking technology introduced in RefinementPro 1, and its exciting new features enable increased work efficiency.
Among these new features, a D-PAS probe can be used to detect turbidity during a titration. This feature can be requested when setting up an pH-Metric titration for pKa, with or without cosolvents present. It will also indicate turbidity during any D-PAS titration for pKa. The D-PAS turbidity option is used for titrations in the standard Sirius vials.
The Assay Planner feature allows users to set-up a tray of assays from a simple text file without manually setting up the tray sample-by-sample. It's a great time saver for analysing substantial numbers of sample using similar methods.
A standard RefinementPro 2 installation can be enhanced by adding Fast D-PAS software for four minute pKa measurement, and CheqSol software for solubility measurement.
Overview
Fast D-PAS UV pKa screening allows fast pKa measurement with no loss in data quality.
Titrations are performed in the presence of a unique linear buffer solution. This buffer solution allows the pH electrode to reach a stable value very quickly after each addition of titrant.
Fast D-PAS UV pKa measures pKa for water-soluble samples in just four minutes. Water-insoluble samples are measured in water-solvent mixtures using a multiple titration.
It takes less than 10 minutes to do a 3-titration assay over a range of pH 2 to 12, covering a range of cosolvent dilution, say from 50% to 30%. A Yasuda-Shedlovsky extrapolation to the aqueous pKa is plotted automatically.
Reference spectra for Fast D-PAS UV pKa experiments are obtained from a Buffer Calibration titration. In this procedure, a blank solution is titrated over the full pH range, and the UV spectra are saved after each addition of titrant. This procedure provides reference spectra of the highest quality and only needs to be performed once per day.
Overview
Solubility measurement on SiriusT3.
The Solubility module for SiriusT3 offers the ability to measure equilibrium solubility by pH-metric titration, using two powerful methods - our patented CheqSol method for dynamic and fast determinations with potentiometric cycling and a Bjerrum method which uses a whole curve fitting approach. In combination these methods can measure solubility for all ionizable compounds.
Our Solubility module provides unique information about Supersaturation and the precipitation & dissolution kinetics of ionizable molecules. We can rapidly measure both the extent and duration of supersaturation, under aqueous or cosolvent conditions and in the presence of additives, excipients and biorelevant media.
Overview
Automated, miniature Dissolution under physiologically relevant pH values
Our Dissolution upgrade for SiriusT3, adds the capability to perform dissolution and precipitation studies at physiological pH values in a standard Sirius assay vial. A small volume of concentrated buffer solution is placed in a vial, after which drug samples are introduced as pressed pellets or free powders, and then quickly diluted with water to the starting volume. The solution is quickly adjusted to the required pH, and then under constant stirring the UV absorbance of the solution is monitored with time. After a user-definable time period the pH is adjusted to a new value, and monitoring continues. Up to Four different pH zones can be investigated in a single assay vial, covering the pH range experienced during passage of a drug through the GI tract.
