Chlorpromazine HCl Research Articles

Functional observational battery (FOB) tests using caffeine and chlorpromazine hydrochloride in sprague-dawley rats.

Caffeine is believed to exert its therapeutic effects by acting as a nonselective, competitive antagonist of adenosine receptors. Chlorpromazine, a phenothiazine, is a classic psychotropic mediator extensively used in the clinical administration of psychotic disorders. This study aimed to validate the procedures used for performing Functional Observational Battery (FOB) tests, to demonstrate the proficiency and interobserver reliability during the FOB tests and also to assess effect on neurobehavioral parameters using positive controls in rats. The rats were administered with Caffeine in Milli-Q water as oral gavage at the dose of 20 mg/kg and Chlorpromazine HCl in 0.9% Saline as intraperitoneal route at the dose of 20 mg/kg. No inter-personnel variability was observed in home cage, handling, open field and sensory reactivity observations recorded in Proficiency test. In conclusion, the known effects of positive controls; caffeine and chlorpromazine HCl on neurobehavioral/Functional Observational Battery parameters including autonomic, neuromuscular and sensory reactivity tests were detected in the current study. FOB test procedures for neurobehavioral, grip strength and motor activity are adequate for the detection of neurotoxic effects of positive controls. No major inter-personnel variability was observed between study personnel in neurobehavioural observations.

Rapid colorimetric sensing of chlorpromazine HCl antipsychotic through in situ growth of gold nanoparticles.

Antipsychotic drugs like chlorpromazine hydrochloride (CPZ) are widely used to treat mental illnesses but can accumulate in the environment if not properly disposed of. Long-term exposure to trace levels of such pharmaceuticals may pose health risks. This study reports a colorimetric assay for detection of the antipsychotic drug chlorpromazine hydrochloride (CPZ) based on its ability to reduce gold ions and form gold nanoparticles (AuNPs). Optimization of reaction conditions such as pH, temperature and reagent concentrations enabled quantitative analysis of CPZ concentrations from 0.1-30 μg mL-1, with a detection limit of 0.06 μg mL-1, 0.23 μg mL-1 quantification limit and less than 3.5% RSD. The AuNPs exhibited a characteristic surface plasmon resonance band at 527 nm detectable by UV-vis spectrophotometry. Method validation with spiked serum, urine and environmental water samples demonstrated acceptable accuracy and precision. Interfering substances showed minimal impact, indicating resilience and specificity. This rapid, inexpensive colorimetric assay could facilitate environmental monitoring and biomedical analysis of antipsychotic drugs.

Microbial and histological analysis of rat model of oral candidiasis

Objective: C. albicans infection is the most common opportunistic infection in humans, and the prevalence of this infection has been increasing recently. Exploratory research on materials that have antifungal potential is urgently needed. One of the stages in the study is the use of experimental animal models. By various extrapolations, we designed models of oral candidiasis for men and women. This study aims to evaluate the infection after the treatment we provide, both microbiologically and histologically. Material and Methods: Our male and female rats lowered their immune systems with the corticosteroid methylprednisolone. The rats' drinking water was mixed with antibiotics to disrupt the balance of the oral cavity's normal flora. To facilitate C.albicans exposure and avoid loss of C.albicans, rats were previously injected with chlorpromazine HCL. Results: The microbiological evaluation showed that in male and female rat models, the number of fungal colonies on oral mucosal swab cultures was significantly higher at five and eight days after exposure to putrefactive control mice. Histological evaluation showed that in model rats, the number of hyphae that penetrated the dorsum of the tongue was higher than in control rats five days after exposure. Conclusion: In conclusion, the method we used is proven to produce oral candidiasis model rats, both male, and female

Flow-injection spectrophotometric determination of chlorpromazine HCl based on releasing of sodium persulphate from hydrogel beads, study and applications

A new mode for the FIA method was developed for the estimation of Chlorpromazine HCl(CPH) in pure and pharmaceutical formulation based on the releasing of the oxidizing agent sodium persulphate from the body the hydrogel beads leads to oxidation of drug to pink color product. Homemade FI photometer, single hydrogel bead and green light emitting diod were used for this application. The optimum conditions were 1ml.min-1 flow rate, 100μL injected sample volume, 15sec as purge time of injected sample volume, 0.5mol.L-1 of sodium persulphate that gel bead soaked in and 3hours of soaking time for hydrogel bead inside sodium persulphate solution. The linear range for the variation of instrument response with CPH concentrations was 0.17-0.80mmol.L-1, While the limit of detection (L.O.D) was 0.108x10-8M from the stepwise dilution of the minimum concentration in the linear range. The correlation coefficient(r) was 0.9945. The method was applied successfully for the determination of CPH in pharmaceutical preparation, and paired t-test indicate that there was no significant differences between the new method and the reported method , so on that base the new method can be used as an alternative analytical method.

Spectrophotometric Determination of Chlorpromazine HCl by Oxidative Coupling Method in Pharmaceutical formulations

The research includes the development of spectrophotometric method for determination microgram amounts of CPZ via oxidative coupling with the Sodium sulphacetamide reagent in presence of oxidizing agent potassium persulphate in the acidic medium (pH=1.8) to form a violet colored-dye, which is soluble in water and showed the highest intensity of absorption at λ max 550 nm. The method has been obeyed Beer's Law in the concentration range (2 - 20) µg/ml, with molar absorptivity of 1.2791 ×104 L/ mol. Cm, Sandel Index value 0.0278 µg/cm2. The detection limit 0.1727 µg/ml, with correlation coefficient 0.9983, the relative standard deviation of the method does not exceed 0.8933%, the proposed method was applied successfully for the determination of chlorpromazine hydrochloride in pharmaceutical preparation

Two New HPLC Methods, Assessed by GAPI, for Simultaneous Determination of Four Antipsychotics in Pharmaceutical Formulations: A Comparative Study

Antipsychotics are widely used to treat various mental disorders. Combination therapies were approved by the FDA to treat manic states. Quetiapine fumarate, aripiprazole, asenapine maleate, and chlorpromazine HCl are frequently used for treatment of these disorders. Green analytical chemistry is primarily concerned with reducing waste generated during sample preparation or analysis. Green solvents, such as ethanol, are being used in HPLC as an alternative to acetonitrile. To this purpose, two new chromatographic methods were developed to determine these four drugs simultaneously in their bulk and pharmaceutical formulations. The greenness of both methods was assessed by the green analytical procedure index (GAPI)—one of them was found to be green ecofriendly, and the other had some environmental hazards (conventional)—and this helps laboratories to choose a method that suits their capabilities. The chromatographic separation for both methods was carried out on a Thermo® C18 column. The total separation times were about 11 min and 9 min for the green and the conventional methods, respectively. Using the Student’s t-test and the F-ratio, there was no significant difference between the results of the two methods. These methods have been validated and successfully applied to the analysis of commercial pharmaceutical formulations. Our study could successfully be used in central quality control laboratories, which need a single analytical method to separate more than one compound with similar pharmacological action.

Identification of chlorpromazine hydrochloride role as a new systemic acquired resistance inducer against Magnaporthe oryzae in rice

Chlorpromazine HCL is considered an active ingredient for psychopharmacological agents for humans, the current study was undertaken to determine the ability of chlorpromazine HCL to induce systemic acquired resistance (SAR) in rice plants, to protect rice from blast disease caused by Magnaporthe oryzae. Chlorpromazine HCL was used at different concentrations; 10, 25, 50, 125, 250, 500, 1000 and 2000 mg/L under laboratory and greenhouse conditions. The results showed that chlorpromazine HCL was effective on fungus radial growth on high concentrations of more than 250 mg/L in vitro. Under greenhouse condition, resistance response was significantly improved with low and high concentrations. The potential inducer concentration was 250 mg/L which reached 18.4% of disease severity. The gene expression for chlorpromazine HCL treatment induces some of the indicators for salicylic acid (SA) pathway such as OsWRKY45 and OsNPR1 which recorded 15.14 and 17.79 fold changes, respectively after 24 h of inoculation, and jasmonic acid (JA) pathway such as AOS2, JAMYB and PBZ1 (OsPR10) which recorded 11.27, 10.57 and 13.51 fold changes, respectively, after 24 h of inoculation. The results suggest that chlorpromazine HCL induces SAR in rice against blast disease which could be related to SA and JA defense pathways.

Adsorption of Phenothiazine Derivatives on Graphene – DFT, Docking and MD Simulation

Impurity-related detection and certification cycle assumes significance in drug production and this study provides theoretical structural and spectral characterization of phenothiazine analogues, acepromazine (P1), amitriptyline (P2) and chlorpromazine HCl (P3) and their adsorption with graphene. Reactivity scores suggest these molecule’s properties are adequate, leading to the consideration of potential drug agents. MD simulations could identify P1, P2, P3 and complex with graphene has better binding energy and is more stable in simulation. Enhancement for different wavenumbers are seen in the graphene complex-molecules assembly.

Tissue distribution of polystyrene nanoplastics in mice and their entry, transport, and cytotoxicity to GES-1cells.

With the widespread use of plastics and nanotechnology products, nanoplastics (NPs) have become a potential threat to human health. It is of great practical significance to study and evaluate the distribution of NPs in mice as mammal models and their entry, transport, and cytotoxicity in human cell lines. In this study, we detected the tissue distribution of fluorescent polystyrene nanoplastics (PS-NPs) in mice and assessed their endocytosis, transport pathways, and cytotoxic effects in GES-1cells. We found that PS-NPs were clearly visible in gastric, intestine, and liver tissues of mice and in GES-1cells treated with PS-NPs. Entry of PS-NPs into GES-1cells decreased with the inhibition of caveolae-mediated endocytosis (nystatin), clathrin-mediated endocytosis (chlorpromazine HCl), micropinocytosis (ethyl-isopropyl amiloride), RhoA (CCG-1423), and F-actin polymerization (lantrunculin A). Rac1 inhibitors (NSC 23766) had no significant effect on PS-NPs entering GES-1cells. F-actin levels significantly decreased in CCG-1423-pretreated GES-1cells exposed to PS-NPs. GES-1cell ultrastructural features indicated that internalized PS-NPs can be encapsulated in vesicles, autophagosomes, lysosomes, and lysosomal residues. RhoA, F-actin, RAB7, and LAMP1 levels in PS-NPs-treated GES-1cells were remarkably up-regulated and the Rab5 level was significantly down-regulated compared to levels in untreated cells. PS-NPs treatment decreased cell proliferation rates and increased cell apoptosis. The formation of autophagosomes and autolysosomes and levels of LC3II increased with the length of PS-NPs treatment. The results indicated that cells regulated endocytosis in response to PS-NPs through the RhoA/F-actin signaling pathway and internalized PS-NPs in the cytoplasm, autophagosomes, or lysosomes produced cytotoxicity. These results illustrate the potential threat of NPs pollution to human health.

Molecular dynamics in amorphous pharmaceutically important protic ionic liquid–benzalkonium chloride

In this paper, we report the dielectric measurements at ambient pressure to portray the molecular dynamics of a glass forming pharmaceutical as well as a protic ionic conductor, benzalkonium chloride [BaCl] by means of broadband dielectric spectroscopy. The measurement in macroscopic nature of a stochastic transport theory and of the electric modulus formalism stanchly reproduces the shape of the dispersion of the microscopic ionic movement in terms of translational and ionic diffusive motion of molecular ions. The situation is analogous to most ionic conductors, BaCl showed only single resolved peak in the electric modulus formalism and doesn't show any crystallisation tendency during cooling as well as heating. The temperature dependence of the conductivity relaxation has been fitted by single Vogel–Fulcher–Tamman (VFT) equation. It is found that the value of Tg observed from DSC is significantly higher than one obtained from the α-conductivity relaxation corresponding to 100s indicating that the structural τα(Τ) is longer than conductivity τσα(Τ) for about 10K. Finally, the results were compared with data for other protic ionic conductors like Procaine HCl, Procainamide HCl, Verapamile HCl, Lidocaine HCl, Tramadole HCl and Chlorpromazine HCl and found that BaCl is a good strong glass former.

Fabrication of chemically andin situmodified carbon paste electrodes for the potentiometric determination of chlorpromazine HCl in pure pharmaceutical preparations, urine and serum

Newly developed modified andin situmodified carbon paste sensors were developed for the determination of chlorpromazine hydrochloride (CPZHC) in pharmaceutical formulations and biological fluids (urine and serum).

Formulation and Stability of an Extemporaneously Compounded Oral Solution of Chlorpromazine HCl

ABSTRACTChlorpromazine is a phenothiazine antipsychotic which is often used in hospice and palliative care to treat hiccups, delirium, and nausea. With the discontinuation of the commercial oral solution concentrate, there is a need to prepare this product by extemporaneous compounding. This study was initiated to identify an easy-to-prepare formulation for the compounding pharmacist. A stability study was also conducted to select the proper storage conditions and establish the beyond-use date. Chlorpromazine HCl powder and the Ora-Sweet® syrup vehicle were used to prepare the 100 mg/mL solution. Once the feasibility was established, a batch of the solution was prepared and packaged in amber plastic prescription bottles for a stability study. These samples were stored at refrigeration (2–8°C) or room temperature (20–25°C) for up to 3 months. At each monthly time point, the samples were evaluated by visual inspection, pH measurement, and high performance liquid chromatography (HPLC). A separate forced stability study was conducted to confirm that the HPLC method was stability indicating. A clear and colorless solution of 100 mg/mL chlorpromazine HCl was obtained by dissolving the drug powder in Ora-Sweet® with moderate agitation. The stability study results indicated that this solution product remained unchanged in visual appearance or pH at both refrigeration and room temperature for up to 3 months. The HPLC results also confirmed that all stability samples retained 93.6–101.4% of initial drug concentration. Chlorpromazine HCl solution 100 mg/mL can be compounded extemporaneously by dissolving chlorpromazine HCl drug powder in Ora-Sweet®. The resulting product is stable for at least three months in amber plastic prescription bottles stored at either refrigeration or room temperature.

Photosafety Screening of Phenothiazine Derivatives With Combined Use of Photochemical and Cassette-Dosing Pharmacokinetic Data

This study aimed to establish an efficient photosafety screening system, employing in vitro photochemical and cassette-dosing pharmacokinetic (PK) studies. Eight phenothiazine (PTZ) derivatives were selected as model chemicals, and photochemical characterization and cassette-dosing PK study were carried out. In vivo photosafety testing on oral PTZs (100 mg/kg) was also assessed in rats. All the tested PTZs exhibited potent UVA/B absorption with molar extinction coefficients of ca. 3400-4400 M(-1)cm(-1). Under exposure to simulated sunlight (2.0 mW/cm(2)), all PTZs, especially fluphenazine 2HCl (FP) and trifluoperazine 2HCl (TF), tended to generate reactive oxygen species (ROS). Casset-dosing PK studies demonstrated high dermal deposition of FP and TF in rats, and from these findings, taken together with the potent photochemical reactivity, both FP and TF were deduced to be highly phototoxic. In contrast, the phototoxic potential of chlorpromazine HCl (CP) seemed to be low because of moderate ROS generation and limited dermal distribution. Predicted phototoxic risk for PTZs from photochemical and PK data appeared basically to agree with the observed phototoxicity in rats; however, oral CP (100 mg/kg) caused severe phototoxic responses in rats. Metabolites of CP have been recognized to be phototoxic, which might explain in part this false prediction. These findings might also suggest the necessity of complementary testing on drug metabolites for more reliable photosafety evaluation. The combined use of photochemical and PK data might be efficacious for simple and fast prediction of the phototoxic potential of new drug candidates.

CNS Depressant and Antiepileptic Activities of the Methanol Extract of the Leaves of Ipomoea Aquatica Forsk

The central nervous system (CNS) depressant and antiepileptic activities of the methanol extract of the leaves of Ipomoea aquatica Forsk (IAF) were investigated on various animal models including pentobarbitone sleeping time and hole‐board exploratory behavior for sedation tests and strychnine, picrotoxin and pentylenetetrazole‐induced convulsions in mice. IAF (200 and 400 mg/kg, p.o.), like chlorpromazine HCl (1 mg/kg, i.m.), produced a dose‐dependent prolongation of pentobarbitone sleeping time and suppression of exploratory behavior. IAF (200 and 400 mg/kg) produced dose‐dependent and significant increases in onset to clonic and tonic convulsions and at 400 mg/kg, showed complete protection against seizures induced by strychnine and picrotoxin but not with pentylenetetrazole. Acute oral toxicity test, up to 14 days, did not produce any visible signs of toxicity. These results suggest that potentially antiepileptic compounds are present in leaf extract of IAF that deserve the study of their identity and mechanism of action.

Sedative and anticonvulsant activities of the aqueous root extract of Sanseviera liberica Gerome & Labroy (Agavaceae)

The central nervous system (CNS) depressant and anticonvulsant activities of the aqueous root extract of Sanseviera liberica (ASL) were investigated on various animal models including pentobarbitone sleeping time and hole-board exploratory behaviour for sedation tests, and strychnine, picrotoxin, bicuculline and pentylenetetrazole-induced convulsions in mice. ASL (100–400 mg/kg, p.o.), like chlorpromazine HCl (1 mg/kg, i.m.), produced a dose-dependent prolongation of pentobarbitone sleeping time and suppression of exploratory behaviour. ASL (100 and 200 mg/kg) produced dose-dependent and significant ( P < 0.05) increases in onset to clonic and tonic convulsions, and at 400 mg/kg, showed complete protection against seizures induced by strychnine, picrotoxin and bicuculline, but not with pentylenetetrazole. ASL up to 10 g/kg, p.o. did not produce death, but i.p. treatment produced mortalities with LD 50 of 668.3 ± 47.6 mg/kg. Preliminary phytochemical investigations of ASL revealed the presence of carbohydrates, alkaloids, saponins, reducing sugars and oils. The results indicate that ASL has sedative and anticonvulsant activities, therefore, justifying its use in traditional African medicine.

The substitution of Phentolamine with an equal amount of Chlopromazine as an alpha-blocker in vasoactive cocktails used for intracavernous injection therapy for the treatment of erectile dysfunction

Introduction: This brief report describes the replacement of phentolamine mesylate with an equal amount of chlorpromazine HCl in vasoactive drug mixtures used as intracavernous (IC) injection therapy for treating erectile dysfunction (ED). Phentolamine, amongst other drugs, had been used in drug injection therapy for the treatment of ED, but was replaced as single drug therapy by more effective drugs, such as alprostadil (prostaglandin E1). It has, however, still widely been used as alpha-blocking agent in vasoactive drug cocktails. Phentolamine has a synergistic effect with alprostadil, papaverine and atropine in drug combination cocktails. These injection mixtures are very effective for treating ED and are commonly known as bimixtures, trimixtures and quadmixtures. The vasoactive drug, phentolamine, was withdrawn from the market in South Africa. Chlorpromazine (a phenothiazine) was suggested as an alternative alpha-blocking agent to be used in drug cocktails for the IC treatment of ED. Methods: Three hundred and sixty-four (364) patients were questioned and evaluated during follow-up visits to an ED clinic after phentolamine mesylate was replaced with an equal amount of chlorpromazine HCL in their regular IC injection preparations. The collected data is based on results from self-administration at home. Results: No significantly unusual adverse effects or altered efficacy of the new preparations were reported. The patients noted a change in the colour of the drug mixtures that contain chlorpromazine and papaverine. Despite this slight change in colour, the effectiveness of the mixtures remained the same if a use-before date of three months was adhered to. Conclusion: The results indicate that phentolamine mesylate can effectively be replaced with an equal amount of chlorpromazine HCL in IC drug cocktails for the treatment of ED. South African Family Practice Vol. 49 (1) 2007: pp. 14

A validated spectrofluorimetric method for determination of some psychoactive drugs

Five psychoactive drugs namely, chlorpromazine HCl, thioridazine HCl, clomipramine HCl, imipramine HCl and desipramine HCl were analyzed by a simple spectrofluorimetric method. The method is based on oxidation of the studied drugs using cerium(IV) in presence of sulphuric acid and monitoring the fluorescence of the formed cerium(III) at λ ex. = 254 nm and λ em. = 355 nm. All variables affecting the reaction conditions such as; cerium(IV) concentration, sulphuric acid concentration, heating time, temperature and dilution solvents were carefully studied. The effect of potential interference due to common ingredients as glucose, sucrose, lactose, citric acid and propylene glycol were investigated. A validation study of the proposed method was carried out according to USP 2002. Beer's law was obeyed for all the studied drugs in the concentration range of 0.05–1.3 μg/ml. Limits of detection range was 0.035–0.038 μg/ml and limits of quantitation of 0.116–0.125 μg/ml were obtained. The method was successfully applied for the assay of the studied drugs in pure form and in pharmaceutical dosage forms. Results were compared with official methods. The t- and F-values were calculated and compared with the theoretical values, which indicate high accuracy and good precision of the proposed method.

Effects of Chlorpromazine·HCl on the Structural Parameters of Bovine Brain Membranes

Fluorescence probes located in different membrane regions were used to evaluate the effects of chlorpromazine .HCl on structural parameters (transbilayer lateral mobility, annular lipid fluidity, protein distribution, and lipid bilayer thickness) of synaptosomal plasma membrane vesicles (SPMVs) isolated from bovine cerebral cortex. The experimental procedure was based on the selective quenching of 1,3-di(1-pyrenyl)propane (Py-3-Py) by trinitrophenyl groups, radiationless energy transfer from the tryptophan of membrane proteins to Py-3-Py, and energy transfer from Py-3-Py monomers to 1-anilinonaphthalene-8-sulfonic acid (ANS). In this study, chlorpromazine .HCl decreased the lateral mobility of Py-3-Py in a concentration dependent-manner, showed a greater ordering effect on the inner monolayer than on the outer monolayer, decreased annular lipid fluidity in a dose dependent-manner, and contracted the membrane lipid bilayer. Furthermore, the drug was found to have a clustering effect on membrane proteins.

Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) infection of human fibroblast cells occurs through endocytosis.

Kaposi's sarcoma (KS)-associated herpesvirus or human herpesvirus 8 (HHV-8) DNA and transcripts have been detected in the B cells, macrophages, keratinocytes, and endothelial and epithelial cells of KS patients. In vitro, HHV-8 infects human B, endothelial, epithelial, and fibroblast cells, as well as animal cells, and the infection is characterized by (i) absence of lytic replication by the input virus and (ii) latent infection. For its initial binding to target cells, HHV-8 uses ubiquitous heparan sulfate molecules via its envelope-associated glycoproteins gB and gpK8.1A. HHV-8 also interacts with the alpha3beta1 integrin via its glycoprotein gB, and virus binding studies suggest that alpha3beta1 is one of the HHV-8 entry receptors (S. M. Akula, N. P. Pramod, F. Z. Wang, and B. Chandran, Cell 108:407-419, 2002). In this study, morphological and biochemical techniques were used to examine the entry of HHV-8 into human foreskin fibroblasts (HFF). HHV-8 was detected in coated vesicles and in large, smooth-surfaced endocytic vesicles. Fusion of viral envelope with the vesicle wall was also observed. In immune electron microscopy, anti-HHV-8 gB antibodies colocalized with virus-containing endocytic vesicles. In fluorescence microscopic analyses, transferrin was colocalized with HHV-8. HHV-8 infection was significantly inhibited by preincubation of cells with chlorpromazine HCl, which blocks endocytosis via clathrin-coated pits, but not by nystatin and cholera toxin B, which blocks endocytosis via caveolae and induces the dissociation of lipid rafts, respectively. Infection was also inhibited by blocking the acidification of endosomes by NH(4)Cl and bafilomycin A. Inhibition of HHV-8 open reading frame 73 gene expression by chlorpromazine HCl, bafilomycin A, and NH(4)Cl demonstrated that the virions in the vesicles could proceed to cause an infection. Taken together, these findings suggest that for its infectious entry into HFF, HHV-8 uses clathrin-mediated endocytosis and a low-pH intracellular environment.

Determination of Five Phenothiazines in Pure and Pharmaceutical Preparations Using Vanadium Pentoxide as a Chromogenic Reagent

Determination of two or more compounds in the same sample without previous chemical separation is a basic analytical problem. In the present study the resolution of the binary mixtures of compounds can be determined by a very simple, sensitive, and accurate spectrophotometric procedure. Five phenothiazine drugs namely, Promethazine HCl (PMH), Promethazine Theoclate (PMT), Chlorpromazine HCl (CPH), Trifluoperazine HCl (TFPH), Prochlorperazine Maleate (PCPM), in pure form and pharmaceutical formulations were assayed by a single chromogenic reagent (V2O5) in an acidic medium, to form a red colored complex having maximum absorbance range from 500 to 525 nm. The reaction is selective for these phenothiazine drugs with 0.05 mg/10 mL as visual limit of quantitation and thus provides a basis for a new spectrophotometric determination. The color reaction obeys Beer's Law from 0.05 mg/10 mL to 2 mg/10 mL for all five phenothiazines with a relative standard deviation from 0.63 to 0.80%. The quantitative assessments of tolerable amounts of other drugs were also studied. The results compare favorably with those of the official methods.