Biosynthesized Gold Nanoparticles Integrated Ointment Base for Repellent Activity Against Aedes aegypti L

The present study focused on preparing a nano-ointment base integrated with biogenic gold nanoparticles from Artemisia vulgaris L. leaf extract. As prepared, nano-ointment was characterized by using Fourier-transform infrared spectroscopy, and the morphology of the nano-ointment was confirmed through a scanning electron microscope. Initially, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide results showed nano-ointment cytocompatibility at different concentrations (20-200 μg/mL) against L929 cells. The in vitro hemolysis assay also revealed that the nano-ointment is biocompatible. Further studies confirmed that nano-ointment has repellent activity with various concentrations (12.5, 25, 50, 75, and 100 ppm). At 100 ppm concentration, the highest repellent activity was observed at 60-min protection time against the Aedes aegypti L. female mosquitoes. The results indicated that the increasing concentration of nano-ointment prolongs the protection time. Moreover, the outcome of this study provides an alternative nano-ointment to synthetic repellent and insecticides after successful clinical trials. It could be an eco-friendly, safer nano-bio repellent, which can protect from dengue fever mosquitoes.

Stability of Compounded Topical Nifedipine in Cream, Gel, and Ointment Bases

The objective of this study was to investigate the stability of compounded nifedipine cream in gel and ointment formulations dispensed in white plastic and glass amber jars. Extemporaneously compounded nifedipine cream (Glaxal Base), gel (K-Y Jelly), and ointment (Aquaphor) in white plastic and glass amber jars were stored at 4°C, 23°C, and 40°C. We determined potency on days 0, 7, 14, 30, 60, and 90, and subsequently assigned beyond-use-dates based on United States Pharmacopeia recommendations, organoleptic properties, and pH changes. Nifedipine potency in cream and ointment stored in white plastic jars was within ±10% of initial for 90 days (excluding day 14 for cream). In glass amber jars, potency was outside the acceptable range by day 14 at 23°C but within range for 90 days at 4°C (excluding day 30). Nifedipine potency was maintained for 90 days in both jars at 23°C and 4°C (excluding day 30) and in white plastic jars at 40°C, but 60 days stored in glass amber jars. The pH of formulations was stable with changes of less than 1-unit pH. At 40°C, a significant decrease in apparent viscosity of cream was evident on day 90. There was a decrease in apparent viscosity and phase separation of the ointment at 40°C and an increase in apparent viscosity (difficult to mix) at 4°C on day 14 onwards. Significant organoleptic changes were observed by day 7 at 40°C (decrease in apparent viscosity and abnormal odor by day 90), day 30 at 4°C (thicker consistency), and day 90 at 23°C (abnormal odor). Storage in white plastic jars at 23°C is recommended for compounded topical nifedipine cream and ointment (for 90 days), and for gel (60 days).

Tacrolimus action pathways in an ointment base for hypertrophic scar prevention in a rabbit ear model

BACKGROUND

Tacrolimus is used to prevent unaesthetic scars due to its action on fibroblast activity and collagen production modulation.

OBJECTIVES

To evaluate the action pathways, from the histopathological point of view and in cytokine control, of tacrolimus ointment in the prevention of hypertrophic scars.

METHODS

Twenty-two rabbits were submitted to the excision of two 1-cm fragments in each ear, including the perichondrium. The right ear received 0.1% and 0.03% tacrolimus in ointment base twice a day in the upper wound and in the lower wound respectively. The left ear, used as the control, was treated with petrolatum. After 30 days, collagen fibers were evaluated using special staining, and immunohistochemistry analyses for smooth muscle actin, TGF-β and VEGF were performed.

RESULTS

The wounds treated with 0.1% tacrolimus showed weak labeling and a lower percentage of labeling for smooth muscle actin, a higher proportion of mucin absence, weak staining, fine and organized fibers for Gomori's Trichrome, strong staining and organized fibers for Verhoeff when compared to controls. The wounds treated with 0.03% tacrolimus showed weak labeling for smooth muscle actin, a higher proportion of mucin absence, strong staining for Verhoeff when compared to the controls. There was absence of TGF-β and low VEGF expression.

STUDY LIMITATIONS

The analysis was performed by a single pathologist. Second-harmonic imaging microscopy was performed in 2 sample areas of the scar.

CONCLUSIONS

Both drug concentrations were effective in suppressing TGF-β and smooth muscle actin, reducing mucin, improving the quality of collagen fibers, and the density of elastic fibers, but only the higher concentration influenced elastic fiber organization.

The Low Prevalence of Allergic Contact Dermatitis Using a Petrolatum Ointment Containing Lanolin Alcohol

Lanolin alcohol is a high cholesterol containing naturally derived material used as a skin protectant in wound healing petrolatum-based ointments. It is a highly purified fraction of lanolin wool wax that has been identified as a possible cause of allergic contact dermatitis. This 3-center study enrolled 499 subjects who underwent a variety of in-office surgical procedures followed by application of a wound healing ointment containing lanolin alcohol without antibiotics. No allergic contact dermatitis was identified in the 499 subjects who completed the study. The lack of allergic contact dermatitis observed may be due to the proprietary highly purified lanolin alcohol utilized in the study formulation. This is not the lanolin alcohol preparation found on the standard dermatology patch test tray. Not all lanolin alcohols are equal. This is an important consideration when examining the reported incidence of allergic contact dermatitis to lanolin alcohol and the absence of allergic contact dermatitis demonstrated in this research. J Drugs Dermatol. 2019;18(10):1002-1004.

Petroleum Jelly: A Novel Medium for Ocular Ultrasound

BACKGROUND

Ocular ultrasound is a useful emergency department imaging modality for evaluation of many conditions, such as retinal detachment, vitreous detachment, vitreous hemorrhage, and elevated intracranial pressure. Obtaining satisfactory ocular ultrasound images requires the use of a medium that eliminates the air interface between the patient's eye and the transducer. Ultrasound gel is most commonly used; however, the use of a transparent dressing applied to the closed eye prior to the application of gel has also been described as a suitable technique.

DISCUSSION

Ocular ultrasound is performed with the high-frequency linear array transducer using a medium to eliminate the air interface between the eye and the transducer. Although ultrasound gel is most frequently used, it can cause minor eye irritation. Placing a transparent dressing over a closed eye prior to application of gel can eliminate the eye irritation. However, our experience in training >500 students in ocular ultrasound has shown that air is frequently introduced underneath the dressing, which leads to poor-quality images. This article introduces petroleum jelly as a medium for ocular ultrasound. By applying a layer of petroleum jelly over the closed eye and allowing it to warm via body heat for 30 to 45 s, this medium can both minimize patient discomfort and provide easily obtainable, high-quality ocular ultrasound images.

CONCLUSIONS

This article introduces petroleum jelly as a safe, comfortable, and effective medium for ocular ultrasound examination.

A flowchart for selecting an ointment base

OBJECTIVES. To improve students' skills in selecting appropriate ointment bases through the development and implementation of a flowchart.

DESIGN

A flowchart was designed to help students select the appropriate base for an ointment. Students used the flowchart throughout the semester in both dry and wet laboratory activities. At the end of the semester, students completed a dry laboratory practical that required them to select an appropriate ointment base and levigating agent.

ASSESSMENT

Student performance data from the year prior to implementation was compared to data for 2 years after implementation. Calculation, procedure, and labeling errors also were compared. Prior to implementation of the flowchart, 51 of 101 students selected the correct base. After implementation, 169 of 212 students selected the correct base (p<0.001). Calculation, procedure, and labeling errors were not significantly different. CONCLUSION. Use of a flowchart to select an ointment base improved student performance when used in the context of a dry laboratory assignment.

Effect of rosmarinic acid on atopic dermatitis

Rosmarinic acid is known to have anti-inflammatory and immunomodulatory activities. This study was performed to evaluate the effect of rosmarinic acid on atopic dermatitis (AD), one of the inflammatory disorders of the skin. Twenty-one subjects (14 women and seven men, 5-28 years of age) with mild AD participated in this study. Rosmarinic acid (0.3%) emulsion was topically applied to the elbow flexures of AD patients twice a day (once in the morning and once in the evening). All subjects were evaluated for skin conditions before treatment at the first visit, and then at 4 and 8 weeks after treatment. According to local Severity Scoring of Atopic Dermatitis index results, erythema on antecubital fossa was significantly reduced at 4 and 8 weeks (P < 0.05). Transepidermal water loss of the antecubital fossa was significantly reduced at 8 weeks compared to before treatment (P < 0.05). The results from self-questionnaires on the efficacy of rosmarinic acid indicated that dryness, pruritus and general AD symptoms improved. Our investigation into the AD-mitigating effect of rosmarinic acid through in vivo experiments demonstrated the possible clinical use of rosmarinic acid as a therapeutic agent for AD.

Analysis of in vitro skin permeation of 22-oxacalcitriol from ointments based on a two- or three-layer diffusion model considering diffusivity in a vehicle

In the present study, in vitro rat skin permeation of 22-oxacalcitriol (OCT) from ointments having differing compositions was determined and discussed based on a diffusion model. Diffusion coefficients of OCT in two ointments, one containing 3% (w/w) medium chain triglyceride (MCT) (3MO) and the other 30% (w/w) MCT (30MO), were determined using a modified membraneless method resulting in values of 0.89x10(-4) and 1.87x10(-4) cm2/h, respectively. At 24 h after application with 3MO, 7% of the applied OCT dose permeated through full-thickness skin and 22% remained in the ointment, whereas with 30MO, 2% of the applied dose permeated through full-thickness skin and 65% remained in the ointment. The diffusion coefficient of OCT in 3MO was lower than 30MO but the cumulative amount of OCT permeated was higher. From analysis of skin permeation of OCT based on a diffusion model considering diffusivity in an ointment, the partition coefficient of OCT from the ointment to stratum corneum (K(SC/V)) was calculated to be five-fold higher with 3MO than with 30MO. Our simulation study based on a diffusion model suggests that the diffusion coefficients of OCT in both ointments were high enough to have no affect on the skin permeation of OCT in the present case and that the difference in the skin permeations of the ointments was mainly caused by a difference in K(SC/V).

Microsphere Based Improved Sunscreen Formulation of Ethylhexyl Methoxycinnamate

Polymethylmethacrylate (PMMA) microspheres of ethylhexyl methoxycinnamate (EHM) were prepared by emulsion solvent evaporation method to improve its photostability and effectiveness as sunscreening agent. Process parameters like stirring speed and aqueous polyvinyl alcohol (PVA) concentration were analyzed in order to optimize the formulations. Shape and surface morphology of the microspheres were examined using scanning electron microscopy. Particle size of the microspheres was determined using laser diffraction particle size analyzer. The PMMA microspheres of EHM were incorporated in water-removable cream base. The in vitro drug release of EHM in pH 7.4 was performed using dialysis membrane. Thin layer chromatography was performed to determine photostability of EHM inside the microspheres. The formulations were evaluated for sun protection factor (SPF) and minimum erythema dose (MED) in albino rats. Cream base formulation containing microspheres prepared using EHM:PMMA in ratio of 1:3 (C(3)) showed slowest drug (EHM) release and those prepared with EHM: PMMA in ratio of 1:1 showed fastest release. The cream base formulations containing EHM loaded microspheres had shown better SPF (more than 16.0) as compared to formulation C(d) that contained 3% free EHM as sunscreen agent and showed SPF 4.66. These studies revealed that the incorporation of EHM loaded PMMA microspheres into cream base had greatly increased the efficacy of sunscreen formulation approximately four times. Further, photostability was also shown to be improved in PMMA microspheres.

Quality of extemporaneously compounded nitroglycerin ointment

PURPOSE

Published clinical trials support the use of 0.2 to 0.4 percent nitroglycerin ointment for the treatment of an anal fissure, although no product is yet available in the United States. In 2004, 84,000 prescriptions were written for compounded nitroglycerin ointment. This study was designed to evaluate the quality of extemporaneously compounded nitroglycerin ointment.

METHODS

Prescriptions for 0.3 percent nitroglycerin ointment were filled at retail pharmacies and shipped to analytical laboratory for analysis by their validated method.

RESULTS

Five of 24 (20.8 percent) samples did not meet the United States Pharmacopoeia requirement for content uniformity of 90 to 110 percent and< 6 percent relative standard deviation. Seven of 24 samples (29.2 percent) were subpotent based on the United States Pharmacopoeia requirement of 90 to 115 percent of label claim, and 1 sample was suprapotent. When considered for potency and/or content uniformity, 11 of 24 (45.8 percent) were misbranded and poor quality.

CONCLUSIONS

Forty-six percent of the nitroglycerin ointment products compounded by 24 pharmacies did not meet the United States Pharmacopoeia specifications for potency and/or content uniformity when filling a prescription for 0.3 percent nitroglycerin ointment. These results raise significant issues regarding whether patients are put at undue risk relative to the relief of anal fissure pain. The pain associated with chronic anal fissure is severe, often debilitating, and may affect the patient's ability to work.

Influence of particle size on the quantitative determination of salicylic acid in a pharmaceutical ointment using FT-Raman spectroscopy

A second order polynomial calibration model was developed and statistically validated for the direct and non-destructive quantitative analysis - without sample preparation - of the active pharmaceutical ingredient (API) salicylic acid in a pharmaceutical ointment using FT-Raman spectroscopy. The calibration curve was modeled by plotting the peak intensity of the vector normalized spectral band between 757 and 784cm(-1) against the known salicylic acid concentrations in standards. At this band, no spectral interferences from the ointment vehiculum (white vaseline) are observed. For the validation of the polynomial model, its fit and its predictive properties were evaluated. The validated model was used for the quantification of 25 ointments, compounded by different retail pharmacists. The same standards and samples were used, both for development and validation of a regression model and for quantitative determination by HPLC - with sample preparation - as described for the related substances of salicylic acid in the Ph. Eur. IV. The quantification results obtained by the FT-Raman method corresponded with the HPLC results (p=0.22), provided that the particle size of salicylic acid in the standards is the same as in the analyzed samples. The non-destructive FT-Raman method is a reliable alternative for the destructive HPLC method, as it is faster and does not require sample pre-treatment procedures.

Pharmacokinetics of tacrolimus following topical application of tacrolimus ointment in adult and pediatric patients with moderate to severe atopic dermatitis

OBJECTIVE

To characterize the pharmacokinetics of tacrolimus after topical application in adult and pediatric patients with moderate to severe atopic dermatitis from all clinical trials in which tacrolimus blood levels were obtained.

METHODS

Tacrolimus ointment 0.03% or 0.1% was applied twice daily. In the adult and pediatric pharmacokinetic studies, serial blood samples were obtained after single and repeated topical application. During the 12 clinical efficacy trials of tacrolimus ointment, single blood samples were obtained at various times relative to tacrolimus ointment application.

RESULTS

In the pharmacokinetic studies, 89% to 95% of tacrolimus whole blood concentration samples were less than 1 ng/mL; mean maximum concentrations ranged from 0.2 to 1.6 ng/mL and mean area under the blood concentration-time curves (0-12 hours) ranged from 1.4 to 13.1 ng x hr/mL. Likewise, in the clinical efficacy trials, the majority (85%-99%) of tacrolimus concentration samples were less than 1 ng/mL.

CONCLUSIONS

Tacrolimus ointment is associated with minimal systemic absorption and no evidence of systemic accumulation in patients with moderate to severe atopic dermatitis and extensive disease.

The "bubble point" for validation of drug release or simulated absorption tests for ointments

The aim of the present study was to design a test to ascertain the behaviour and reliability of a membrane used in drug release and simulated absorption tests in order to arrive at useful indications for simulating topical as well as gastro-intestinal absorption. The membrane can be used in two different conditions: a) as a simple porous membrane placed between the ointment and an accepting liquid phase, generally water phase; b) as a membrane soaked in a lipophilic liquid phase to simulate the horny layer between the ointment and accepting water phase. In this study the "bubble point test" was used to test the integrity of the soaking film as well as the membrane, during and after drug release and simulated absorption tests with different types of ointment. In the case of a drug release test from an ointment, the bubble point test may determine the test conditions, that is the ointment applied to either a dry or hydrated membrane. Only the use of a previously hydrated membrane can guarantee constant conditions in the in vitro model. Use of a dry membrane may lead to infiltration of liquid components of the ointment base, thus altering the contact conditions between the two phases of the cutaneous compartment model (lipogel and W/O creams). The use of a hydrated membrane may also lead to interactions between the two phases of the compartment, with osmotic exchanges between the acceptor phase and ointment sample (hydrogel, PEG gel, O/W creams). The hydrated membrane is therefore reliable only for comparison between lipophilic base ointments. In a simulated absorption test, determination of the bubble point makes it possible to ascertain the physical integrity of the lipoid liquid film immobilized by capillary action in the inner microporous structure of the membrane during the test. This condition is essential to maintain a balance between the parameters regulating the diffusion process between the different compartments of the system. The use of a lipoid-soaked membrane makes it possible to avoid interactions between the ointment sample and an aqueous acceptor phase, such as hydrosoluble bases. Since the diffusion across a lipoid film immobilised within a porous membrane depends on the drug release rate from the ointment base, the test allows a contextual evaluation of the release kinetics as well as an indication of the drug absorption possibilities through an in vitro model of the cutaneous compartment.

[Treatment of bedsores--combination of therapies depended the experimental design method]

The treatment of bedsores is a particular problem in geriatric medicine. We selected standard drugs that may be effective for the decubitus ulcer, and investigated combination therapy to develop efficient treatment The subjects were 16 patients in whom the grade of the bedsore was evaluated as II to IV according to the Shea's depth classification. Treatment was performed while all patients were on air mats. We selected drugs and treatment methods based on the previously established experimental design of Taguchi. Based on this, we created and adapted 16 different component combination treatment programs in accordance with the L16 rectangular cross table. The following component factors were adopted: A: types of covering substances on the wound surface (Elase ointment, isodine sugar, isodine gel solcoseryl ointment); B: Isalopan powder; C: Spray of 10 ml physiological saline containing 500 microg of prostaglandin (concentration 0.005%); D: daily number of treatments; and F: presence or absence of tapping. We serially measured the wound surface area as an index of the speed of wound healing, and measured the interval (day) until the area decreased to one half of the original size (T1/2, half life). We analyzed data on one combination treatment each in 16 patients. Analysis of variance of the above factors showed significant F values for factors A, B, D and F. The contribution rates for factors A, B, D and F were 37.84%, 8.47%, 14.98% and 13.81%, respectively. The error term (e) was 16.37%. Optimal results were seen in the groups in which solcoseryl ointment had been applied twice a day. In this study, prostaglandin, which had been anticipated to be effective, did not show any effects. The error term (e) suggests the presence of other healing factors including individual differences. Concerning this point, it well be necessary to examine a larger number of patients in the future. With ointment treatment alone, without using an air mat, it was confirmed that bedsore area reduction was extremely unstable. Decompression of the affected part may be a basic prevention factor and essential treatment of bedsores.

Penciclovir Cream – Improved Topical Treatment for Herpes simplex Infections

Human herpesviruses can be found worldwide and cause many viral infections in immunocompetent as well as in immunocompromised patients. Herpes simplex virus (HSV) diseases can be the cause of life-threatening disease, especially in neonates. After initial infection, HSV persists latently in host neurons with the risk of periodical reactivation over a lifetime. The development of acyclovir, a potent and specific nucleoside inhibitor of the herpes DNA polymerase, was a milestone in the history of antiviral drugs in the late 1970s. During the last decades a better understanding of the replication and disease-causing state of HSV types 1 and 2 has been achieved enabling the development of new and potent antiviral compounds. In the mid-1990s, for example, valacyclovir and famciclovir were launched as prodrugs of acyclovir with improved bioavailability. Despite the numerous drugs available for the systemic treatment of HSV infections, the topical application of a cream containing an antiviral agent is still the most convenient method of treating herpes simplex labialis/facialis in the general population. For some time, the topical standard treatment for recurrent HSV infections has been acyclovir cream, despite the fact that the evidence for efficacy in recurrent episodes has been equivocal. Penciclovir, a novel acyclic nucleoside analogue, has demonstrated efficacy against HSV types 1 and 2 and seems to have a pharmacological advantage due to a prolonged half-life of its active form in HSV-infected cells. This review discusses and compares the topical treatment modalities available for HSV infections. As a conclusion, different studies are available that have shown that it is possible to reduce viral replication and hasten lesion resolution with 1% penciclovir treatment beyond the prodromal phase of the HSV infection. Comparing data of topical treatment with acyclovir and penciclovir revealed a superiority for penciclovir cream showing a significant decrease in time to lesion healing, lesion area and pain. While systemic acyclovir or valacyclovir may be valid drugs especially for HSV prophylaxis, 1% penciclovir cream should be preferred as topical treatment since there are good therapeutic results independent of the phase of development of herpetic eruptions.

Vehicle effects on in vitro release of tiaprofenic acid from different topical formulations

The aim of the present study was to investigate the in vitro release properties of tiaprofenic acid (TA) from different topical vehicles. Carbopol 940 gel, chitosan gel, two types of emulsion-based ointment formulations (o/w and w/o) and hydrophilic petrolatum USP were prepared with 2% drug content. Drug release from all vehicles through a standard cellophane membrane was evaluated by using Franz-type diffusion cells. In vitro release study results showed that the diffusion coefficients of the drug from vehicles rank according to the following order: Carbopol 940 gel (D = 3.11 x 10(-7) +/- 0.54 cm(2)/s) > chitosan gel (D = 0.27 x 10(-7) +/- 0.08 cm(2)/s) > emulsion-based ointment (o/w) (D = 0.18 x 10(-7) +/- 0.05 cm(2)/s) > emulsion-based ointment (w/o) (D = 0.13 x 10(-7) +/- 0.02 cm(2)/s) > hydrophilic petrolatum USP (D = 0.02 x 10(-7) +/- 0.01 cm(2)/s). Carbopol 940 gel base showed significantly higher drug release than other vehicles (P < 0.001). These results indicated that Carbopol 940 gel base is a good candidate for the topical delivery of TA, giving significantly higher drug release than the other vehicles.

Calcipotriol versus coal tar: a prospective randomized study in stable plaque psoriasis

BACKGROUND

Topical therapies are the first line of treatment for patients with stable plaque psoriasis (SPP) affecting a limited body surface area. Very few trials comparing newer agents, such as 0.005% topical calcipotriol, with conventional modes of therapy, such as coal tar ointment, have been reported.

METHODS

A prospective, right-left randomized, investigator-blinded study with a 12-week treatment period and an 8-week follow-up period was performed. Thirty-six patients with nearly bilaterally symmetrical SPP lesions on the limbs were instructed to apply 5% coal tar ointment overnight on one side once daily and 0.005% calcipotriol ointment on the other side twice a day. All patients were advised to expose both sides to the sun for 2 h every day. Psoriatic lesions and progress during treatment were evaluated using the severity (0-3) scale of erythema, scaling and induration (ESI score). Evaluation was carried out every 2 weeks during the treatment period and monthly during follow-up. At the end of 12 weeks, patients with > 75% reduction in the ESI score were considered to be markedly improved, those with 51-75% reduction to be moderately improved, those with 26-50% reduction to be minimally improved and those with < 25% to be non-responders. Self-assessment by the patients regarding the efficacy and acceptability of the two modalities was on a five-point scale. Serum calcium, serum phosphate, total and differential serum proteins, 24-h urinary calcium and phosphate were monitored both at baseline and after completion of therapy.

RESULTS

Thirty of the 36 recruited patients completed the study. The difference in clinical response between the two sides was statistically significant at 4, 6 and 8 weeks, with the percentage reduction in ESI score with calcipotriol being 65.7 +/- 12.2% compared with 45.8 +/- 16.6% with coal tar at 8 weeks (P < 0.01, t = 6.4). However, the difference in clinical response at 10 and 12 weeks between the two sides was not significant, with a mean reduction of 71.9 +/- 13.3% in ESI score on the calcipotriol-treated side compared with 69.4 +/- 15.4% with coal tar ointment (P > 0.05). In the follow-up period of 8 weeks, recurrence of lesions was noted in 10% of patients treated with calcipotriol compared with 16.7% in those treated with coal tar after an average period of 6 +/- 1.2 and 5 +/- 1.3 weeks, respectively (P > 0.05).

CONCLUSIONS

It was found that 0.005% calcipotriol ointment produced a faster initial response and had better cosmetic acceptability in patients, although after a long period of treatment, i.e. 12 weeks, 5% coal tar ointment had comparable efficacy. There was no statistically significant difference in the relapse rates between the two modalities.

Preparation of a Gel-Forming Ointment Base Applicable to the Recovery Stage of Bedsore and Clinical Evaluation of a Treatment Method with Different Ointment Bases Suitable to each Stage of Bedsore

An ointment base for better treatment of bedsores was developed to improve the release rate of minocycline hydrochloride (MH) and the water absorption capacity using various types of hydrophobic to hydrophilic ointment bases. The effect of purified lanolin (PL) on the release behavior of MH from a hydrophilic ointment (HO) base was the primary focus. It was found that the drug release rate from the ointment base was modified according to the method of preparation of the ointment base and the type of cyclodextrins admixed. The physicochemical properties, such as viscosity, elution volume, and water absorption, of the ointment base were also modified by those factors. To develop an ointment formulation suitable for the recovery stages of bedsores, including the proliferation period of granulation and the formative period of epidermis, the physicochemical properties of Macrogol ointment containing various hydrophilic polymers, which have gel-forming ability, were tested. A novel ointment base suitable for the treatment in the recovery stage of bedsores was developed using hydrophobically modified hydroxypropyl methylcellulose (HM-HPMC). Considerably sustained release of MH (T50 of 170 at a min) was attained with a macrogol ointment mixed with HM-HPMC and Carbopol formulation ratio of 3:7. We clinically evaluated the effectiveness of bedsore treatment by applying different ointment bases to patients with different stages of bedsores.

Pimecrolimus cream 1% can be an effective treatment for seborrheic dermatitis of the face and trunk

The ascomycin macrolactam derivative pimecrolimus is a novel, nonsteroidal, cell-selective inhibitor of inflammatory cytokines specifically developed for the treatment of inflammatory skin diseases. Our objective was to assess the efficacy, tolerability and safety of pimecrolimus cream 1% in the treatment of seborrheic dermatitis. Adults with seborrheic dermatitis of the face and upper trunk who were seen from October 2003 to April 2004 at the Dermatologic Outpatient Clinic of the University of Thrace were enrolled in this 9-week open-label uncontrolled study. Pimecrolimus cream 1% was applied as monotherapy twice daily for 7 days and for an additional period of 7 days thereafter, if needed, until complete clearance was achieved. In cases of recurrence a 5-day course was additionally applied. After screening and an appropriate washout period, subjects were evaluated at baseline (day 0) and at follow-up visits at weeks 1, 3, 6 and 9. The clinical severity of seborrheic dermatitis was estimated as mild (total score 1-3), moderate (total score 4-6) and severe (total score 7-9) in terms of erythema, scaling and lesional extent using a scale from 0 to 3 for each. Patients also assessed their symptoms on a scale from 0 to 5 in terms of the efficacy, safety and tolerability of topical application. Nineteen patients (12 males, seven females) were enrolled in this study. At the end of weeks 1, 3, 6 and 9 the percentages of complete clearance were 63%, 100%, 47% and 52%, respectively. At the end of the study, subjects' average assessment score was 9.73. Apart from topical burning and irritation of the skin in four patients, no other adverse event was mentioned. This pilot study indicates that pimecrolimus applied twice daily can be a safe and efficacious alternative in the treatment of seborrheic dermatitis. Further studies are needed to determine the initial and maintenance therapy.

Effect of Petrolatum Coating on the Rate of Occlusion of Ameroid Constrictors in the Peritoneal Cavity

OBJECTIVE

To document rate of closure and degree of inflammation associated with petrolatum coated (PCA) and non-coated ameroid constrictors (NCA) in the peritoneal cavity.

STUDY DESIGN

Experimental study.

ANIMALS

18 Sprague-Dawley rats.

METHODS

Thirty-six ameroid constrictors (AC; 5 mm) were digitally scanned and luminal area measured. Rats were anesthetized, and 1 PCA and 1 NCA were inserted in the peritoneal cavity by median celiotomy. Rats were euthanatized at 2 weeks (6 rats), 4 weeks (6), or 6 weeks (6) after surgery. AC were harvested, digitally scanned, and luminal area determined. Inflammation associated with the AC was subjectively graded (1-5). The effects of petrolatum coating on luminal area measurements and inflammatory score were statistically analyzed.

RESULTS

Closure of AC occurred most rapidly during the first 2 weeks, but luminal area decreased only 32% at 6 weeks after implantation. There was no significant difference in rate of closure for PCA compared to NCA at 2, 4, or 6 weeks. Inflammation scores were not significantly different between PCA and NCA.

CONCLUSIONS

Petrolatum coating did not slow the rate of closure of AC in the peritoneal cavity.

CLINICAL RELEVANCE

The lack of closure of AC supports the conclusion that vascular attenuation is not dependent on luminal constriction alone. Petrolatum coating did not slow the rate of casein expansion and is unlikely to be clinically useful.

[Preparation of a manual treatment of pressure ulcers which draws attention to moisture of the affected part]

As for pressure ulcers care, prevention is the most important approach. However, pressure ulcers, might develop despite enough care, depending on each person's physical condition. As for the treatment of pressure ulcers, maintenance of a moderately moist environment (60-70%) is quite important. We propose the use of ointment to control the moisture of a pressure ulcer environment. One ointment base absorbs moisture, while another provides moisture. We have prepared a manual that allows the user to select the medicine according to the degree of moisture of the affected part. When the moisture cannot be regulated with one ointment, it can be adjusted by mixing two or more ointments. In choosing a drug for external use, it is important to pay attention not only to the effect of the main ingredient but also to the physicochemical properties of the ointment base that serves as vehicle for that active component.

Comparison of effects of different ointment bases on the penetration of ketoprofen through heat-separated human epidermis and artificial lipid barriers

In vitro tests were performed to understand the effects of topical vehicles on the permeability of ketoprofen through artificial lipid barriers and heat-separated human epidermis consisting of stratum corneum and viable epidermis. Ketoprofen was selected as the model penetrant. Human epidermis and artificial membranes made from several mixtures of free fatty acids, cholesterol, cholesteryl ester, ceramides, and triglycerides were used as permeation matrices in untreated conditions and after pretreatment with petrolatum, wool alcohols ointment, or triglycerides. Apparent permeability and diffusion coefficients as well as the solubility of the drug in the artificial lipid matrices were ascertained. The solubilities of drugs and vehicle components that depend on the composition of the lipid matrix predominantly control the permeability of the barrier. Ceramides and cholesterol reduce the permeability and solubility, whereas triglycerides have the opposite effect. The vehicle effects in artificial membranes correspond to those in epidermis observed with samples pretreated with the aforementioned bases. The logarithms of the permeabilities of untreated and pretreated lipid mixtures 3, 4, and 5 are very well correlated with those of the permeabilities of heat-separated epidermis (r > = 0.9868). The artificial mixture containing all five lipids mentioned gives the best approximation to human epidermis. This result indicates comparable vehicle effects although the composition of the artificial mixture was adapted only in a simplified manner to the horny layer lipid phase. This lipid matrix or similar mixtures, therefore, are convenient tools for investigation into the effects of dermatological vehicles.

[Development of prodioxin ointment]

There was a purpose to create a composite ointment of proteolytic and antimicrobial activity, the formulation of which would contain the proteolytic enzyme procelan and the antimicrobial preparation with wide spectrum of action dioxidin. During the development of prodioxin ointment by means of biological experiments the optimal concentration of dioxidin was evaluated; it was 1 percent. The optimal dispersity value of dioxidin particles was estimated by dialysis through a semipermeable membrane. The best release of dioxidine from prodioxin ointment occurred, when it was pulverized to particles with diameter 5-10 mm. The method of assay of dioxidin was modified for the ointment. The physicomechanical properties of the prodioxin ointment: flowability, colloidal stability, thermostability and rheological properties were examined. The investigated ointment is non-newtonian in character, e.g. an elastic and plastic system and may be intended for use in dermatological practice. Medicinal enzymic and antimicrobial effects of the prodioxin ointment were compared with the healing effect of Iruksol ointment. The medicinal effect of the prodioxin ointment exceeded that of Iruksol ointment by one day. Judging by the results of the physicochemical analysis a conclusion can be made that the prodioxin ointment is stable for two years at room temperature.

[Development of technology of the enzyme preparation: procelan ointment]

When investigating the release of procelan from diphilic, hydrophobic and hydrophilic basis we determined that the best release of the active substance is from hydrophilic basis. The macrogolic base when compared with methylcellulosic one shows clearly expressed osmotic properties and therefore is more suitable as a base for ointments intended to treat suppurative wounds. This was confirmed by treatment of experimentally excited suppurative wounds on rabbits. Hydrophilic ointments containing lyophilized procelan powders from 4 per cent to 20 per cent were examined. The most remarkable therapeutic effect reached with the ointment of macrogolic base, optimal concentration of procelan being 10 per cent. The method of assay of procelan in the ointment was created. The created dosage form is stable for three years at room temperature.

[The excipient properties of shea butter compared with vaseline and lanolin]

A shea butter ointment containing 3% aureomycin (clortetracyclin hydrocloride) was prepared and some of its macroscopic and microscopic characteristics were evaluated. Then, the release of the active ingredient was compared by UV spectrophotometry with those obtained when excipients such as petroleum jelly and lanoline were used. Results had shown that the shea butter ointment had satisfactory characteristics. In the other hand, it was found that shea butter released the aureomycin easily and at a faster rate than the other excipients.

Pharmacotechnical characterization and effectiveness testing of a proposed emulsion for the treatment of dry skin

One of the most important objectives of the Pharmaceutical Industry is the development of new excipients as well as the optimization of other more traditional ones. Also, the investigation of new active substances able to prevent, palliate or treat the cutaneous dehydration is another of the most important of their objectives. Both tendencies are implanted in this experimental work: we propose an emulsion formulated with the base--Neo PCL' (25%), NMF (Lactil', 5%) and a peculiar active--Honey of Rosemary (15%). The working scheme is as follows: 1) Pharmacotechnical Characterization--organoleptic characteristics, Photomicrograph Study, Type of Emulsion, pH, Rheology; 2) Stability Study by means of accelerated tests based on temperature and centrifugation; 3) Effectiveness Study by applying of non-invasive assessment techniques. An emulsified dermopharmaceutical form is obtained (O/W) with a satisfactory organoleptic characteristics and eudermic pH (5.2), attributable to the acid character of Honey. From the rheological study, a very good results are obtained: viscosity (T = 408.8.D0.549), structural recuperation (30%) and thixotropy (AD1/AD2 = 1.36). On the other hand, from the effectiveness results (corneometric--P.I.120 = 43.2%- and sebumetric--E.I. = 33-144 mg/cm2-), a high level of moisturizing is deduced, which is attributable to the synergic action of both Lactil' and Honey. Finally, the proposed emulsion would serve as a treatment for all type of dry skin.

The influence of dilution of topical semisolid preparations on hydrocortisone permeation through excised human stratum corneum

Dilution of semisolid preparations, in order to tailor the formulations to the needs of the patients, was thought to be associated with a number of dangers, one of which is the unpredictable alteration of activity. In the present study the influence of dilution on hydrocortisone permeation through excised human stratum corneum was investigated. The permeation profiles of hydrocortisone from various cream bases (diluted and undiluted) were found to be very similar with no significant differences. This result was in accordance with the lack of interaction between the tested bases and the structure of stratum corneum as shown by differential scanning calorimetry experiments. Thus, the permeability of stratum corneum, which was not affected by the cream bases, is the rate limiting step for drug permeation. However, it could be shown that dilution of Soventol cream (placebo with 1% hydrocortisone) which is known to contain isopropyl myristate as permeation enhancer reduces drug permeation. The reduced hydrocortisone permeation is believed to be due to reduced enhancer concentration.

Enhancement of skin permeation of miconazole by phospholipid and dodecyl 2-(N,N-dimethyl amino)propionate (DDAIP)

Miconazole (MCZ) has very low solubility in both water and oil. Permeation rates through shed snakeskin from an aqueous suspension and a mineral oil suspension were 0.5 microg/cm(2)/h and almost none, respectively. When hydrogenated phosphatidylcholine (HPC) was added to mineral oil and heated to 95 degrees C, the solubility of MCZ increased in proportion to the HPC concentration. DSC measurements also indicated an interaction between them. Thus, a gel formed by hydrogenated phospholipid and mineral oil, as vehicle was prepared. The solubility of MCZ in the gel was around 1% and the permeation rate was 1.3 microg/cm(2)/h, which was about 2.5 times that from an aqueous suspension. As an alternative approach, a skin permeation enhancer, dodecyl 2-(N,N-dimethyl amino)propionate (DDAIP) was applied 2 h before a skin permeation study. The permeation from an aqueous suspension became 11 times that of the suspension without DDAIP pretreatment. The concentration of MCZ in the skin increased 8-fold, indicating that the enhancement effect involved high partition of MCZ into the skin. On the other hand, when a gel formulation was used, pretreatment with DDAIP was not as effective as incorporation of DDAIP in the gel formulation. Following pretreatment, permeation was only two times that of the gel without DDAIP pretreatment, and half that of the water suspension with DDAIP pretreatment. This suggested that release from the gel was the rate-limiting step with the gel formulation. When DDAIP was added to the gel, the permeation rate of MCZ was 3.3 microg/cm(2)/h. It was also a release limited type permeation. The gel with DDAIP is potentially a useful formulation, because of relatively high permeation while possibly avoiding overdosing.

Efficacy of a new class of perfluoropolyethers in the prevention of irritant contact dermatitis

Perfluoropolyethers (Fomblin HC products) are chemical non-reactive polymers with special physico-chemical properties that recently showed promise as protective preparations in the prevention of irritant contact dermatitis. We evaluated the efficacy of a new class of perfluoropolyethers (perfluoropolyether phosphate, Fomblin HC/P2) in the prevention of experimentally induced cumulative irritant contact dermatitis if applied prior to irritation. A panel of 20 healthy volunteers was tested with a repetitive irritation test using 4 standard irritants (sodium lauryl sulphate of highest purity, sodium hydroxide, lactic acid and toluene) in a randomized double-blind study. Application sites were assessed clinically and by the use of bioengineering techniques (transepidermal water loss and chromametry). Three gel preparations each containing 5% perfluoropolyether phosphate showed significant efficacy against irritation due to sodium lauryl sulphate and sodium hydroxide, while one test preparation containing 2% showed inferior benefit, indicating a dose-related effect. Preparations containing perfluoropolyether phosphates can be recommended for workplaces with water-soluble irritants. Further studies under real workplace conditions are indicated.

Transdermal absorption of phytoestrogens

The transdermal absorption of the isoflavones, daidzein and genistein, applied on the skin in olive oil was studied in vivo. The concentrations of the isoflavones and their metabolites were monitored in plasma and urine by GC-MS methods. It was found that the concentration of genistein in plasma was 3-fold higher than the plasma concentration of daidzein. In contrast, daidzein excretion was 2-3-fold higher than that of genistein in urine. The excretion rate of the studied phytoestrogens in urine and their concentration in plasma was significantly decreased after repeated transdermal application. The urinary recovery of administered daidzein and genistein after the first application was 15.9% and 7.7%, respectively and this dropped to 1.6% and 0.7% after the second application. The results obtained might suggest that daidzein and genistein are captured in the skin following repeated transdermal application.

Honey, a prospective antibiotic: extraction, formulation, and stability

Old and recent reports show that honey has beneficial effects on the skin as antiseptic for wounds, burns and ulcers and as a healing promoter. Many investigators confirmed the usefulness of honey in the treatment of skin infections as well as internal diseases. The factors behind these effects are not completely explained. The aim of this study is: a) to investigate the antimicrobial activity of crude honey, b) to separate the fractions responsible for its activity, c) to formulate the honey extract as semisolid dosage forms, d) to study its release, and e) to determine its stability. The results showed that the ethylacetate honey extract showed antibacterial, anticandida and antifungal effects at low concentration. The release of honey extract from different ointment bases was depending on the constituents of the base, and its stability was found to be temperature and base dependent.

[Preparation of a gel-forming ointment base applicable to the recovery stage of bedsore and clinical evaluation of a treatment method with different ointment bases suitable to each stage of bedsore]

A novel ointment base suitable for the treatment of bedsore at the recovery stage was developed by the use of hydroxypropyl methylcellulose (HM-HPMC) modified on the basis of the hydrophobicity. A considerable sustained release of drug (minocycline hydrochloride) formulated to the ointment (T50 of 170 min) was attained with a macrogol ointment (MO) mixed with the HM-HPMC and Carbopol (CP) of the formulating ratio of 3:7. It was also found that a change in the formulating ratio of HM-HPMC and CP lead to a change in the drug release rate. The water absorption property of the ointment base, required to absorb on exudative solution in applying to the bedsore treatment, was as high as that of an ointment base containing hydroxypropyl cellulose (HPC) and CP reported in our previous paper. We clinically evaluated the effectiveness of the bedsore treatment, in which different ointment bases were applied to patients at different stages of the bedsore. A total of 22 cases were divided into two categories for applying to the different treatments. One category comprised of 11 subjects was treated with a povidone-iodine sugargel, which was the conventional method in our hospital, while the other 11 subjects were treated by the use of the newly developed ointment bases in consideration for the different stages of the bedsore. In comparison of the clinical results with the healing index, we ascertained that the latter method was significantly more efficacious (p < 0.01-0.05) than the conventional one. The effectiveness was emphasized in treating the intractable bedsore classified into the grades IV and V. Therefore, we confirmed that the newly developed ointment base formulation is useful in treating bedsore at each stage.

Evaluation of creams and ointments as suitable formulations for peldesine

In-vitro studies were conducted to study the efficacy of mixed and self-emulsifying creams and hydrophobic ointment formulations in delivering peldesine (BCX-34) into and across cryopreserved human cadaver skin (HCS). Oil-in-water cream formulations, containing 1% w/w of radiolabeled C(14) BCX-34 and propylene glycol (PG), glycerin (GLY), isopropyl myristate (IPM), oleic acid (OA) and capric-caprylic esters (CE) were prepared. Petrolatum and lanolin based ointments were also prepared with PG. Sections of the HCS, 250 microm thick, were fitted to vertical Franz diffusion chambers containing a receptor medium of pH 7.4 phosphate buffer solution maintained at 37 degrees C. Using the finite dose technique, 4-6 mg of a formulation sample was applied to the epidermal surface of each section and drug diffusion was permitted for 12 and 24 h periods. The distribution of drug into the HCS epidermis, dermis and into the receptor medium was measured by scintillation spectroscopy. The results show good correlation of the calculated in-vitro values for flux and skin-vehicle partition coefficients against the observed amounts of drug detected in the HCS. The mixed emulsion cream formulation containing PG delivered higher amounts of drug into the skin when compared to the same formulation containing GLY cream. The self-emulsifying cream formulation containing IPM had a higher skin-vehicle partition coefficient and delivered more drug into the dermis when compared to those formulations that contained OA and CE. The petrolatum ointment delivered six times more drug into the epidermis than the lanolin ointment, and had higher skin-vehicle partition values. In conclusion, creams containing PG and petrolatum-base formulations would be suitable for BCX-34 dermal delivery.

Effect of drug solubility on in vitro availability rate from suppositories with polyethylene glycol excipients

Factors involved in the availability mechanism of different drugs from suppositories with polyethylene glycol (PEG) excipients were studied using an in vitro model of the rectal compartment with a porous membrane simulating the rectal barrier. Different from lipophilic excipients, the drug is released as a consequence of the progressive dissolution of PEG into the intrarectal aqueous phase. Drug concentration in this small intrarectal phase produces the gradient against the large volume of the plasmatic phase, which regulates the diffusion rate through the barrier. As with lipophilic excipients, drug solubility in water was found to be an important factor influencing suppository release rate. Nevertheless, PEG influenced in vitro drug availability considerably, by increasing both drug solubility and dissolution rate. The osmotic effect of PEG in the intrarectal compartment influenced the increase in volume of the aqueous phase. The results, compared with those obtained from suppositories with a lipophilic excipient, show a higher dissolution rate from PEG excipient, but a higher diffusion rate across the barrier did not always correspond. Drugs less soluble in water showed a greater availability from PEG suppositories. On the contrary the more soluble drugs were less available.

[The preparations and spectroscopic studies of infrared radiating materials]

ZrO2 and ZrO2-Al2O3 samples have been prepared by precipitation method, and characterized by FTIR, NIR FT-Raman, XRD and IR emission spectra, respectively. The result showed that these samples are the better infrared radiating materials, which have high efficiency and excellent properties. When compared with pure ointment, ZrO2-Al2O3 prepared has more strong infrared emission peaks. The application of infrared radiating materials in ointment may have a good effect on thermal infrared absorption vibration and absorption of medicine by sick part of body.

Characterization of vernix caseosa as a natural biofilm: comparison to standard oil-based ointments

The application of occlusive films and oil-in-oil ointments has been reported to improve epidermal barrier function in very low birthweight, preterm infants. Such infants have a structurally immature stratum corneum and lack a surface coating of vernix caseosa. In this study we examined the short-term effects of topical application of vernix caseosa to human skin and contrasted these effects with commonly used ointments and water-in-oil emulsions. Specifically, vernix, Eucerin(R), Aquaphor(R), and petrolatum were applied to the volar skin surface of adult volunteers. Surface electrical capacitance (SEC) and transepidermal water loss (TEWL) were measured as indices of surface hydration. Sorption-desorption profiles were performed to determine skin surface hydrophobicity. Particular attention was given to monitoring the acute (0-120 minutes) changes following vernix treatment in order to compare these effects with earlier reports on the rate of skin surface drying in newborn infants following birth. Immediately after vernix application there was an increase in the rate of water loss from the skin surface. Relative to control skin and skin treated with the ointments and water-in-oil emulsions, the application of vernix to freshly bathed human skin resulted in a unique profile of temporal change in baseline surface hydration, moisture accumulation, and water-holding capacity. These results demonstrate major differences between human vernix and standard oil-based topical ointments. The results provide a framework for discussing the various properties of topical barriers applied to the very low birthweight infant.

Modification of the physicochemical properties of minocycline hydrochloride ointment with cyclodextrines for optimum treatment of bedsore

Modification to find the best physicochemical properties of minocycline hydrochloride ointment for optimum treatment of bedsore was investigated by coformulating various types of cyclodextrins (CyD) in the ointment base. It was found that the drug release rate from the ointment base was modified according to the preparation method of ointment base and the type of CyD admixed. The physicochemical properties, such as viscosity, elution volume, water absorption of ointment base were also modified by those factors. The mechanism of physicochemical modification with CyD was explained by the structural change of ointment base and the change of surface tension of emulsifying agent solution with the CyD. The stability of ointment was investigated by confirming the reproducibility of drug release rate after storage at ambient and cooled temperature conditions. In conclusion, a fused mixed ointment with beta-CyD was found to be preferable for treatment of bedsore, because of the improved drug release rate, lowered viscosity and increased elution volume of the resultant ointment.

Systemic candidiasis in extremely low birth weight infants receiving topical petrolatum ointment for skin care: a case-control study

BACKGROUND AND OBJECTIVE

An increase in the incidence of systemic candidiasis (SC) followed a change in skin care for extremely low birth weight (ELBW) infants in our neonatal intensive care unit (NICU). We sought to determine whether the use of topical petrolatum ointment (TPO) for skin care of ELBW infants was associated with risk for SC.

STUDY DESIGN

Case-control study.

SETTING

A 48-bed NICU in a private hospital in Houston, Texas.

PATIENTS

Ten ELBW infants with and 30 without SC admitted to the NICU from December 1, 1997 through July 31, 1998.

METHODS

ELBW infants with SC were identified using hospital microbiology and infectious disease consultation databases. A case was defined as an infant weighing </=1000 g at birth with Candida spp isolated from a normally sterile body site. Three infants without SC were matched to each case by birth weight, admission date, and survival to the age of SC onset for the case. Data were collected by retrospective medical record review. Molecular analysis of Candida isolates was performed by karyotyping and restriction fragment length polymorphism using pulsed-field gel electrophoresis.

RESULTS

Case infants had a mean (+/- standard deviation) age of onset of 21.5 +/- 24 days. Infants with SC and controls did not differ in birth weight, gestational age, or duration of therapy with steroids, antibiotics, insulin, or total parenteral nutrition. Although cases were more likely to be born vaginally and had a longer duration endotracheal intubation than controls, these differences were not significant. The odds ratio for skin care with TPO in case infants versus control infants was 11 (95% confidence interval: 1.9-63). Skin care with TPO was discontinued and the incidence of SC decreased to baseline. Several Candida spp and genetic profiles were identified, suggesting that there was not a common source outbreak.

CONCLUSIONS

We conclude that the use of TPO promoted an increase in the incidence of SC in ELBW infants. Additional investigation of potential infectious risks for ELBW infants receiving TPO skin care is warranted.

A novel percolation method for determining solubilities of pharmaceutical agents in semisolid vehicles

A novel technique was developed to quantify the solubility of pharmaceutical actives in semisolid formulations. Ointments and emulsions of increasing potencies were sheared to disrupt their internal microcrystalline networks. These sheared materials were held in taut cheesecloth pouches, and the bleed that percolated out was collected and assayed for active potency. The solute concentration in the bleed was proportional to the concentration of the solute in solution in the formulation. Plots of bleed active potency against total formulation potency rose linearly to the point of formulation saturation. Above saturation, bleed potencies remained constant, producing plateaus on the solubility plots. The formulation potency at the onset of plateau quantified the saturation solubility of the active in each formulation. This technique was demonstrated with butylparaben in three ointment bases, and with hydrocortisone in an emulsion formulation. The solubility estimates thus obtained were confirmed experimentally by optical microscopy. This novel technique permits saturation solubilities to be determined for a range of semisolid formulations, with much greater accuracy than was previously possible.

Percutaneous transport of diclofenac sodium from mixtures of fatty alcohol (or fatty acid) and propylene glycol through the rabbit abdominal skin

Diclofenac sodium is a nonsteroidal anti-inflammatory drug with analgesic, antipyretic, and anti-inflammatory activity. When used in a topical application, diclofenac can diffuse through the skin and into the subcutaneous tissue to effect the anti-inflammatory action. In this study, in vitro evaluations of the percutaneous transport of diclofenac sodium in various bases containing fatty alcohols/propylene glycol or fatty acid/propylene glycol mixtures through the abdominal skin of the rabbit were investigated. Results show that the transdermal flux of diclofenac sodium in the fatty alcohol/propylene glycol bases of the same ratio is affected by the chain length of the fatty alcohol, and its effect is in the order of C10 > C12 > C14 > C18. However, the transdermal flux of diclofenac sodium in the fatty acid/propylene glycol bases of the same ratio is also affected by the chain length of the fatty acid, but no absolute relationship was found. For the same chain length of fatty acid and fatty alcohol used in the formulation base that was otherwise the same, the transdermal flux of diclofenac sodium is higher in the formula containing fatty alcohol than that containing fatty acid.

Long-term stability of 8-methoxypsoralen in ointments for topical PUVA therapy ('Cream-PUVA')

8-Methoxypsoralen (8-MOP) is an established photochemotherapeutic agent for PUVA therapy. Recently, a so-called 'cream-PUVA' modality was introduced into therapy of psoriasis and other dermatoses. Little is known, however, about the stability of 8-MOP in ointments used for the topical application of this compound. Therefore, we investigated the long-term stability of 8-MOP in three different ointments, Unguentum Cordes(TM), Cold Cream Naturel(TM) and a water-containing gel on the basis of Carbopol 940. All three ointments were prepared with 8-MOP concentrations of 0.05 and 0.005%, and stored over 12 weeks at room temperature (19-20 degrees C) and at 5 degrees C. 8-MOP concentrations were measured at days 1, 8, 15, 29, 57 and 88 after preparation by thin-layer chromatography (TLC). The ointments were dissolved in an organic solvent, 10 microl were transferred onto the TLC plate and the chromatograms were developed first in toluene and then in toluene/ethyl acetate 2:1 v/v to resolve 8-MOP from the ointment constituents. The peak heights of 8-MOP were used for quantitation. The intraday variabilities are <3% for Unguentum Cordes and Cold Cream Naturel and <6% for the Carbopol 940 gel. The interday variabilities were <6.3% in all cases. In Unguentum Cordes and Cold Cream Naturel the concentrations of 8-MOP remain stable, but in Unguentum Cordes the emulsion began to break up after 8 weeks. In the Carbopol gel, only about 40% of the nominal concentrations of 8-MOP were found and they decrease significantly at storage at 5 degrees C. We conclude that the Carbopol gel seems to be unsuitable for PUVA therapy, whereas Cold Cream Naturel shows the best results.

Use of gelatin-acacia coacervate containing benzocaine in topical formulations

The in vitro release of a drug from topical formulations depends on the concentration of the drug in the formulation, the solubility of the drug in the base, the diffusion coefficient of the drug in the vehicle, and the partition coefficient of the drug between the vehicle, and the release medium. Incorporation of both complexing agents and cosolvents into such formulations has been used to enhance the in vitro release of a drug from topical formulations. In this investigation, a novel approach to enhance the in vitro release of benzocaine from different ointment formulations has been introduced. In this study, benzocaine was microencapsulated using gelatin-acacia complex coacervation technique. Various weight fractions of the coacervate, 5, 10, and 20% (w/w), were incorporated into both oleaginous and absorption bases. The in vitro release characteristics of benzocaine from the resulting ointments were studied using a modified USP Dissolution Apparatus 2. A plot of the cumulative amount of drug released (7-8%) per unit surface area versus (time)(1/2) was linear. Microscopic studies of the formulations revealed that the coacervates maintained their integrity in the formulation during the preparation and storage of the dosage form. Differential scanning calorimetric (DSC) studies indicated that the drug existed in the crystalline state in all formulations including those at a low drug load (0.5% w/w). DSC was also used to determine the solubility of the drug in the formulation. The rate and extent of drug release was higher in the absorption base as compared to the oleaginous base.

Mixed base of hydrophilic ointment and purified lanolin to improve the drug release rate and absorption of water of minocycline hydrochloride ointment for treatment of bedsores

A desired ointment bases for better treatment of bedsores was developed to improve the release rate of minocycline hydrochloride (MH) and the water absorption capacity using various types of hydrophobic to hydrophilic ointment base. The influence of purified lanolin (PL) on the release behavior of MH from hydrophilic ointment (HO) base was primarily focused on. It was found that the release rate of drug increased with increase in the hydrophilicity of the base. A linear correlation between the apparent release rate constant of drug from the HO and PL mixed ointment base at various combination ratios and the elution of ointment base was noted. The HO ointment base containing 30% PL had the highest apparent release rate constant of MH. The mixed ointment base with the lowest viscosity showed the highest absorption of water and elution of ointment base. In conclusion, it was found that HO (70%) and PL (30%) mixed ointment base was a promising candidate for better treatment of bedsores.