Emulsion Type Base Research Articles

Review of Ointment Formulations in Modern Pharmaceutics

Ointment formulations refer to semisolid topical formulations of a certain consistency made by homogeneous mixing of the drug with a suitable base. Ointments made with an emulsion type base are called creams. Ointment agents since the aspects of liquid formulations mainly protect wounds, lubricate the skin and local treatment, etc., some drugs can have a local onset of action after transdermal absorption and can also produce systemic therapeutic effects. Therefore, ointment formulations have attracted much attention for their advantages of convenient use, stable properties, good dissolution properties, and are also one of the important directions in modern pharmaceutics research.

Efficacy of biorhythmic transdermal combined hormone treatment in relieving climacteric symptoms: a pilot study.

Objective:To evaluate the efficacy of a combination of bioidentical combined 17β-estradiol and progesterone transdermal delivery system (lipophilic emulsion-type base) to relieve climacteric symptoms. The hormonal replacement was given during a period of 6 months at four different cyclic doses to mimic the normal ovary secretory pattern.Design:An open, randomized, comparative, between-patient trial conducted over 6 months in 29 menopausal women with climacteric symptoms assessed with the Kupperman index at baseline and during treatments. Saliva and serum values of 17β-estradiol and progesterone were quantitated before treatment and after 3 and 6 months. Pharmacokinetic data following transdermal administration of 17β-estradiol (0.3 mg, daily) and progesterone (100 mg, daily) were calculated from saliva levels using high-performance liquid chromatography analysis.Results:Improvement in climacteric symptoms was reported in 93% of women evaluated before and after 3 and 6 months of treatment. Values of saliva 17β-estradiol increased after 6 months from 0.6 ± 0.3 pg/mL to 14.1 ± 3.3 pg/mL, and the values of serum 17β-estradiol increased from 3.3 ± 2.8 pg/mL to 80.6 ± 21.9 pg/mL. Of responders, 88% characterized symptom relief as complete. No adverse health-related events were attributed to the bioidentical hormone therapy. Time to maximum saliva concentrations (Tmax), in all experimental cases, was observed after 6 hours. Baseline values were reached within 24 hours, indicating a diurnal rhythm of 17β-estradiol seen in normally cyclic women over the 24-hour period, ie, its daily biological rhythm.Conclusion:Percutaneous absorption of 17β-estradiol, as well as the absorption of progesterone, was associated with relief of climacteric symptoms. The cyclical transdermal delivery of combined bioidentical hormones may be advantageous because it mimics the secretory profiles of 17β-estradiol and progesterone in normally cyclic women over a 28-day period. Larger studies are needed to determine the long-term effects of our therapy.

In vitro permeation study of capsaicin and its synthetic derivatives from ointment bases using various skin types

Nonivamide (NVA) and sodium nonivamide acetate (SNA) both are synthetic analogues of capsaicin. In the present study, in vitro penetration experiments through rat skin from ointment bases were performed in order to establish and develop the transdermal drug delivery system of these two capsaicin analogues. This study was also carried out to evaluate the relative skin permeability of capsaicin and its derivatives through different skin types. As regards the in vitro transdermal absorption of ointment bases, o/w emulsion-type bases (hydrophilic and University of California Hospital (UCH) ointment) revealed better percutaneous absorption effects than the others for both NVA and SNA. However, there was a higher accumulative amount for NVA in the gel base but none for SNA. There were no changes observed in the appearance and texture when the aqueous phase of the three ointment bases (hydrophilic, absorption and UCH ointment) was replaced by pH 4.2 buffer. In the steady-state flux of absorption ointment for NVA and UCH, absorption ointment for SNA was significantly higher (P < 0.05) in pH 4.2 buffer-replaced base than in the original. In the comparison of in vitro permeability through various animal skin types, full-thickness human skin showed the poorest permeability for NVA, SNA and capsaicin. The trends of steady-state flux through the various skin types for capsaicin, NVA and SNA were quite different. However, pig skin could be successfully used as a model to study in vitro percutaneous absorption of these three compounds through human skin.

Physicopharmaceutical Characteristics of an Oil-in- Water Emulsion-Type Ointment Containing Diclofenac Sodium

The oil-in-water (o/w) emulsion-type ointment was prepared with food additives containing diclofenac sodium. The oil phase and the emulsifier used were 1,2,3-propanetriyl trioctanoate (caprylic acid glyceryl ester) and sugar wax, and sugar ester, respectively. The emulsion stability of the o/w emulsion-type ointment as well as the diclofenac sodium release profile were investigated and compared with those from conventional ointments. The emulsion stability was evaluated in terms of the viscosity of the emulsion product, the particle size distribution of oil droplets, and the zeta potential of the droplets. It was found that sugar esters have excellent properties as emulsifiers, based on the results of viscosity and zeta potential measurements. The in vitro release test revealed that the amount of diclofenac sodium released from o/w emulsion-type ointment was greater than from the hydrophilic and absorptive ointments. Accordingly, it was concluded that o/w emulsion-type bases are suitable for pharmaceutical use in ointment products.

Studies on pharmaceutical drug design for suppositories. I. Effect of physicochemical properties of surfactants and polymers on emulsion-type bases.

In general, it is recognized that emulsion-type bases have outstanding characteristics for suppository products as compared with simple hydrophilic or hydrophobic bases. The purpose of this work was to investigate the effect of some surfactants or polymers on the physicochemical properties of emulsion-type suppository bases. Witepsol S-55, which is a trilauryl acid glycerin ester derivative, was used as the oil phase. The emulsifiers used were commercial grade Amisoft ; CS-11, GS-11, and HS-21, and the polymers used were sodium alginate, sodium carboxymethylcellulose and sodium polyacrylate. In addition, the emulsion stability was evaluated in terms of (1) the rheological properties, (2) the particle size and its distribution, (3) the mean and distribution of electrophoretic mobility. It was found that (1) Amisoft surfactants are excellent emulsifiers when compared with sodium dodecyl sulfate or Tweens based on the particle size and viscosity measurements, and (2) the addition of aqueous polymers is effective in stabilizing emulsion bases. Accordingly, emulsion-type bases should be suitable for pharmaceutical use in suppository products.

A Study of the Antibacterial Activity of Some Complex Aluminum Salts

Previous reports have shown that some aluminum salts are antibacterial. The deodorant activity of these salts is partly due to antibacterial action. Aluminum formo acetate and aluminum basic formate were found to possess antibacterial activity in an oil-in-water base and a water-washable base. Aluminum chlorhydroxide complex and aluminum amino acetate showed little or no zone of inhibition in the four types of bases used. pH and the nonionic surfactants Tween® 80 and Span® 40 evidently had little or no influence on the zones of inhibition produced by the two formic acid salts. For the greatest antibacterial activity of an aluminum salt, an oil-in-water emulsion-type base should be employed.

The Effect of Topically Applied Hyaluronidase on Cutaneous Permeability to Certain Substances

Studies were made to determine if hyaluronidase, when incorporated into ointments, affected the penetration of medication contained in ointments applied to the skin. Four substances were tested: sulfanilamide, sodium sulfanilamide, sodium iodide, and sodium chloride. Three different ointment bases were used: an oleaginous base, an absorption base, and a washable emulsion type base. The ointments were applied to the intact skin of guinea pigs, and a technique using radioactive isotopes is reported for determining the extent of penetration of the labeled medicaments. It was found that the substances studied showed a limited degree of penetration into the skin from the bases used, but except in the case of sodium iodide the penetration was not appreciably affected by hyaluronidase.

A Study of Suppository Bases.: I.Review of Literature

A review of the literature on suppository bases shows that much work has been done on fattype bases such as cocoa butter. Some investigations have been made on water-soluble and emulsion type bases. There seems to be little or no work done with such compounds as plastics, synthetic resins, and other similar condensation products. The review on sup pository bases includes 108 references, containing data in classified form.

The In Vitro Fungistatic Action of Some Nitrofuran Derivatives

The fungistatic action of some nitrofuran derivatives against a series of fungi has been investigated by an accepted in vitro test. Outstanding activity was noted in the case of two derivatives, 5-nitro-2-furfuryl methyl ether and 5-nitro-2-furaldehyde oxime. There was no structural specificity apparent in the compounds studied. In order to observe the effect of vehicle upon activity various bases were included in the study to compound the nitrofuran derivatives. The emulsion type base allowed the maximum fungistatic activity to be displayed.

Diffusion of sulfonamides from emulsified ointment bases

Twenty‐four of the investigators reviewed have compared the results of clinical investigation of sulfonamides suspended in oil‐in‐water base with sulfonamides suspended in water‐in‐oil base, grease base, or water‐miscible base. In vitro tests indicate that the sulfa drugs suspended in an oil‐in‐water emulsion type ointment base diffuse more readily than sulfa drugs suspended in the water‐in‐oil emulsion type ointment base. In vitro tests indicate that diffusion increases with the miscibility of the base. The addition of a large amount of the wetting agent dioctyl sodium sulfosuccinate (Aerosol OT) increases the diffusion of sulfa drugs suspended in the watet‐in‐oil emulsion type base. The addition of lanolin to triethanolamine emulsions containing sulfathiazole increases slightly the diffusion of sulfathiazole.

Bacterial Flora of Normal Skin: A Study of the Effect of Sulfathiazole and Some Ointment Bases

The growing importance of local sulfonamide therapy in dermatology (1, 2, 3, 4) and the relative paucity of literature dealing with the effects of ointment bases on skin bacteria has prompted the present investigation. The latter problem was partially studied by Pillsbury, Livingood and Nichols (5) in a previous report. These workers used the method of Price (6) as modified by Pohle and Stuart (7) in determining the effect of various cutaneous applications in changing the rate at which bacteria were removed from the skin during a standard scrubbing technic. They found, in brief, that certain ointments, when applied to the skin for periods varying between several minutes and one hour, resulted in a rise in bacteria recovered as compared to scrubbing experiments where no applications were used. The ointments used included petrolatum, lanolin, 3% and 5% ammoniated mercury in ointment, IJ.S.P., 3% and 5% ammoniated mercury in an emulsion type base, phenylmercuric nitrate (1:1,500) in an emulsion type base, and lastly ointment U.S.P. Similar effects were noted with distilled water, 0.02% aqueous solution of potassium permanganate, 0.1% aerosol in water, 0.5% aqueous solution of aluminum acetate and the simple wearing of rubber gloves. A suggestion was made that this rise in bacterial count might be due to the softening action of the various applications allowing better removal of bacteria, surface debris and superficial stratum corneum. The opposite action was observed following the local use of 70% ethyl alcohol and Castellani's Carbolfuchsin paint. Of interest, in connection with these findings, is a study by Cromwell and Leffler (8) using a technic similar to the above workers. They found that astringent substances (ethyl alcohol and potassium alum) have a hardening action on the epidermis and, thereby, prevent bacteria from being scrubbed off the skin. By contrast, other substances (sodium sulphide and ammonium suiphide) which tend to soften the epidermis result in a rise in bacterial count.