Stability indicating high performance thin layer chromatography method development and validation for quantitative determination of tetracycline hydrochloride in tetracycline hydrochloride active pharmaceutical ingredient (API) and its dosage forms.

Simple, quick, cost-effective, and environmentally friendly analytical methods for quality assurance and control roles for different medicines, including Tetrcyclines, are most significantly needed. Also, different thin layer chromatography (TLC)-based methods for tetracycline identification exist, but high performance thin layer chromatography methods based on modern state- of- the art equipment are still nonexistent. Thus, in this study, analytical method development and verification were done by high performance thin layer chromatography (HPTLC) (using an automated equipment model) using glass plates coated with silica gel 60 F254 after treating with 10% Na2EDTA. Validation was carried out according to International Council for Harmonization (ICH) guidelines. A mobile phase formed from ethyl acetate, acetonitrile, methanol, and 1% aqueous ammonia in the composition of 4.4:19.6:10:6 volume to volume ratio (V/V) was used. Rf value, percentage recoveries, linearity ranges, limit of detection (LOD), and limit of quantitation (LOQ) for the developed HPTLC method were 0.28, 100.83-106.25%, 160-560 ng/band (r2 values of 0.9999), 31.9 ng/band, and 96.7 ng/band, respectively. The results of the sample assays conducted using the new method and the United States Pharmacopoeia (USP) high performance liquid chromatography (HPLC) method were 91.59% to 108.3% and 90.83% to 102.85%, respectively. The F test for the aforementioned methods was 2.01, which is smaller than the tabulated F value of 5.05 with 5 degrees of freedom at a 95% confidence range, proving that the newly developed HPTLC and HPLC pharmacopoeial methods can be used interchangeably.The newly developed HPTLC method is easy, economical, specific, accurate, and roboust, thus it can be employed in a range of settings that require quality control and assurance activities of tetracycline hydrochloride (TC-HCl) in bulk and ointment dosage forms.

Development and validation of a high-performance thin layer chromatography method for the simultaneous determination of amoxicillin and clavulanic acid combinations in tablet dosage forms.

A simple and sensitive high-performance thin layer chromatography (HPTLC) method was developed and validated as per the International Council for Harmonization (ICH) guidelines for the simultaneous determination of amoxicillin (AMX) and clavulanic acid (CLA) combinations in tablet formulations. Chromatography was performed on precoated glass plates with normal phase silica gel 60 F254. The mobile phase was acetone:ethyl acetate:glacial acetic acid:water (11:9:4:2 (v/v)). The plate was scanned at a wavelength of 428 nm after derivatization with ninhydrin. The validation of the method revealed that the linearity range lies between 400 and 1200 ng/band for AMX and 100-300 ng/band for CLA, with coefficients of determination of 0.9997 and 0.9966, respectively. Recoveries in standard addition accuracy studies were 100.3 % for AMX and 96.75 % for CLA. The limit of detection (LOD) and limit of quantitation (LOQ) of the developed method are 20.3 ng/band and 61.6 ng/band for AMX and 18.5 ng/band and 56.2 ng/band for CLA, respectively. The new, novel high-performance thin layer chromatography (HPTLC) method that was successfully developed in this study was applied for the simultaneous determination of AMX and CLA in their fixed-dose tablet dosage forms obtained from retail pharmacies and offered comparable results with the official British Pharmacopoeial high-performance liquid chromatography (HPLC) method.

Mean kinetic temperature evaluations through simulated temperature excursions and risk assessment with oral dosage usage for health programs.

BACKGROUND: Temperature excursions occur during the transport and storage of pharmaceuticals, and often result in considerable losses for public health programs operating in countries with limited resources. After a temperature excursion has been identified, often products are discarded without any additional risk assessments. Consulting the manufacturer is the preferred approach but can be challenging depending on the responsiveness of the manufacturer. However, decisions are often required quickly depending on program needs and available stock in country. METHODS: To provide further guidance, simulations have been conducted based on mean kinetic temperature evaluations using accepted default kinetic parameters to assess loss of shelf-life for scenarios involving various levels of temperature excursions on a model pharmaceutical at different recommended storage conditions, shelf-life, and long-term storage conditions. RESULTS: Although an immediate loss to shelf-life occurred with excursions when the product was stored at the maximum allowed temperature, more extended excursion could be withstood before loss of shelf-life was detected when long-term storage was maintained at temperatures below the maximum storage condition for the product. With the assumption that a shelf-life loss of 2 weeks was negligible when managing program stock, a risk assessment was conducted to outline the various times that excursions at different temperatures could be considered low risk to the program. CONCLUSIONS: Depending on the level of the temperature excursion and the guidance provided by the manufacturer, public health programs will have further information with this assessment to guide decisions that impact safety to the end user and resource management due to temperature excursions that can occur.

The Quality of Selected Essential Medicines Sold in Accredited Drug Dispensing Outlets and Pharmacies in Tanzania.

INTRODUCTION: The purpose of this study was to investigate the quality of a select group of medicines sold in accredited drug dispensing outlets (ADDOs) and pharmacies in different regions of Tanzania as part of an in-depth cross-sectional assessment of community access to medicines and community use of medicines. METHODS: We collected 242 samples of amoxicillin trihydrate, artemether-lumefantrine (ALu), co-trimoxazole, ergometrine maleate, paracetamol, and quinine from selected ADDOs and pharmacies in Mbeya, Morogoro, Singida, and Tanga regions. The analysis included physical examination and testing with validated analytical techniques. Assays for eight of nine products were conducted using high-performance thin-layer chromatography (HPTLC). For ALu tablets, we used a two-tiered approach, where tier 1 was a semi-quantitative Global Pharma Health Fund-Minilab® method and tier 2 was high-performance liquid chromatography (HPLC) as described in The International Pharmacopoeia's monograph for artemether-lumefantrine. RESULTS AND DISCUSSION: The physical examination of samples revealed no defects in the solid and oral liquid dosage forms, but unusual discoloration in an injectable solution, ergometrine maleate. For ALu, the results showed that of 38 samples, 31 (81.6%) passed tier 1 testing and 7 (18.4%) gave inconclusive drug content results. The inconclusive ALu samples were submitted for tier 2 testing and all met the quality standards. The pass rate using the HPTLC and TLC/HPLC assays was 93.8%; the failures were the ergometrine maleate samples purchased from both ADDOs and pharmacies. The disintegration testing of the solid dosage forms was conducted in accordance with US Pharmacopeia monographs. Only two samples of paracetamol, 1.2% of the solid dosage forms, failed to comply to standards. The study revealed a high overall rate of 92.6% of samples that met the quality standards. Although the overall failure rate was 7.4%, it is important to note that this was largely limited to one product and likely due to poor distribution and storage rather than poor manufacturing practices. CONCLUSIONS: Over 90% of the medicines sold in ADDOs and pharmacies met quality standards. Policy makers need to reconsider ergometrine maleate's place on the list of medicines that ADDOs are allowed to dispense, by either substituting a more temperature-stable therapeutically equivalent product or requiring those sites to have refrigerators, which is not a feasible option for rural Tanzania.

Characterization of drug authenticity using thin-layer chromatography imaging with a mobile phone.

Thin-layer chromatography (TLC) has a myriad of separation applications in chemistry, biology, and pharmacology due to its simplicity and low cost. While benchtop laboratory sample application and detection systems for TLC provide accurate quantitation of TLC spot positions and densities, there are many applications where inexpensive and portable instruments would greatly expand the applicability of the technology. In this work, we demonstrate identity verification and concentration determination of pharmaceutical compounds via TLC using a custom 3D-printed cradle that interfaces with an ordinary mobile phone. The cradle holds the mobile phone's internal, rear-facing camera in a fixed position relative to a UV lamp and a TLC plate that includes a phosphor in the stationary phase. Analysis of photographs thus reveals the locations and intensities of principal spots of UV--absorbing drugs. Automated image analysis software determines the center location and density of dark spots, which, using integrated calibration spots of known drug compounds and concentrations, can be used to determine if a drug has been diluted or substituted. Two independent image processing approaches have been developed that may be selected based upon the processing capabilities of the smartphone. Each approach is able to discern 5% drug concentration differences. Using single-component solutions of nevirapine, amodiaquine, and paracetamol that have been manually applied, the mobile phone-based detection instrument provides measurements that are equivalent to those obtained with a commercially available lab-based desktop TLC densitometer.

Implementation of 350-2500 nm diffuse reflectance spectroscopy and High-Performance Thin-Layer Chromatography to rapidly assess manufacturing consistency and quality of cotrimoxazole tablets in Tanzania.

OBJECTIVE: To assess the quality of cotrimoxazole tablets produced by a Tanzanian manufacturer by a newly instituted quality assurance programme. METHODS: Tablets underwent a diffuse reflectance spectroscopy procedure with periodic quality assessment confirmation by assay and dissolution testing using validated HPTLC techniques (including weight variation and disintegration evaluations). RESULTS: Based on results from the primary test methods, the first group of product was <80% compliant, whereas subsequent groups reached >99% compliance. CONCLUSIONS: This approach provides a model for rapidly assuring product quality of future procurements of other products that is more cost-effective than traditional pharmaceutical testing techniques.

High-performance thin layer chromatography to assess pharmaceutical product quality.

OBJECTIVE: To assess the sustainability, robustness and economic advantages of high-performance thin layer chromatography (HPTLC) for quality control of pharmaceutical products. METHOD: We compared three laboratories where three lots of cotrimoxazole tablets were assessed using different techniques for quantifying the active ingredient. RESULT: The average assay relative standard deviation for the three lots was 1.2 with a range of 0.65-2.0. CONCLUSION: High-performance thin layer chromatography assessments are yielding valid results suitable for assessing product quality. The local pharmaceutical manufacturer had evolved the capacity to produce very high quality products.

TLC for pharmaceutical analysis in resource limited countries.

This review article discusses the sustainability and robust advantages of planar chromatography that are critical to the successful performance of product quality assessments in resource limited areas including field applications. Because of the robustness and ease of use, the training required for successful performance of the high performance thin layer chromatography (HPTLC) assessments is much lower than that of other technologies with comparable reproducibility such as high performance liquid chromatography (HPLC). Some of the successful applications of planar chromatography in resource limited countries are presented. It should be noted that these planar chromatographic technologies have much lower plate counts and therefore separation power than column technologies such as HPLC and gas liquid chromatography (GLC). However in finished pharmaceutical products there are generally few active ingredients which are assessed making the HPTLC adequate for these analyses. In addition at this time there is a much wider array of detection technologies available for HPLC and GLC.

An interlaboratory investigation on the use of high-performance thin layer chromatography to perform assays of lamivudine-zidovudine, metronidazole, nevirapine, and quinine composite samples.

Two laboratories extensively investigated the use of HPTLC to perform assays on lamivudine-zidovudine, metronidazole, nevirapine, and quinine composite samples. To minimize the effects of differences in analysts' technique, the laboratories conducted the study with automatic sample application devices in conjunction with variable-wavelength scanning densitometers to evaluate the plates. The HPTLC procedures used relatively innocuous, inexpensive, and readily available chromatography solvents used in the Kenyon or the Global Pharma Health Fund Minilabs TLC methods. The use of automatic sample applications in conjunction with variable- wavelength scanning densitometry demonstrated an average repeatability or within-laboratory RSD of 1.90%, with 73% less than 2% and 97% at 2.60% or less, and an average reproducibility or among-laboratory RSD of 2.74%.

The use of Minilabs to improve the testing capacity of regulatory authorities in resource limited settings: Tanzanian experience.

The Tanzania Food and Drugs Authority piloted the use of Minilab kits, a thin-layer-chromatographic based drug quality testing technique, in a two-tier quality assurance program. The program is intended to improve testing capacity with timely screening of the quality of medicines as they enter the market. After 1 week training of inspectors on Minilab screening techniques, they were stationed at key Ports-of-Entry (POE) to screen the quality of imported medicines. In addition, three non-Ports-of-Entry centres were established to screen samples collected during Post-Marketing-Surveillance. Standard operating procedures (SOPs) were developed to structure and standardize the implementation process. Over 1200 samples were tested using the Minilab outside the central quality control laboratory (QCL), almost doubling the previous testing capacity. The program contributed to increased regulatory reach and visibility of the Authority throughout the country, serving as a deterrent against entry of substandard medicines into market. The use of Minilab for quality screening was inexpensive and provided a high sample throughput. However, it suffers from the limitation that it can reliably detect only grossly substandard or wrong drug samples and therefore, it should not be used as an independent testing resource but in conjunction with a full-service quality control laboratory capable of auditing reported substandard results.

Proficiency testing as a tool to assess the performance of visual TLC quantitation estimates.

The use of rapid and inexpensive nonlaboratory-based screening tests for drug quality assessments is recommended as a component of a drug quality assurance program in poor resource settings. We have established routine Minilab test procedures to screen product quality and a proficiency testing program to determine the competency of the inspectors and reliability of results. Samples for the proficiency testing were prepared by pulverizing a standard reference tablet of the appropriate drug and making serial dilutions with starch to obtain concentrations of 0, 40, and 100%. The samples, which were labeled only with the drug name and an identifying letter, were given to inspectors for quality screening using Minilab procedures. In round 1 of the proficiency test, only 3 of 28 substandard samples were correctly identified. Round 2 of the proficiency test, which was administered after a performance qualification test for the analytical method, showed much improvement: 19 of 27 substandard drugs were correctly identified, while 5 out of 9 inspectors made the correct inference on the quality of 45 samples. However, in both rounds, 2 inspectors failed to identify substandard samples, indicating that their technical competencies need to be improved for the reliability of the results. Although the thin-layer chromatography screening methods provide a rapid means for drug quality assessment, they need to be put in the hands of competent users. The inclusion of a proficiency test in the screening program provides a measure of determining competency of the personnel and reliability of the results.