Creams formulation

Dahl MV, Jarratt M, Kaplan D, Tuley MR, Baker MD (2001) Once-daily topical metronidazole cream formulations in the treatment of the papules and pustules of rosacea. J Am Acad Dermatol 45 723-730... 

The cooling sensation experienced after applying a cosmetic cold cream on one s skin is the result of the evaporation of an alcohol (e.g., ethanol) contained in the cold cream. Formulators of skin products include ethanol to achieve a variety of benefits. For example, alcohol enhances the ability of the components in the cold cream to dissolve. For the consumer, the presence of alcohol eases the application of the cream on the skin, enhances the perfume quality of the mixture, and provides a cooling effect on the skin. 

Goger and Gokcen [19] developed a quantitative method for the determination of miconazole in cream formulations that contain benzoic acid as preservative by second order derivative spectrophotometry. The procedure was based on the linear relationship in the range 100—500 pg/mL between the drug concentration and the second-derivative amplitudes at 276 nm. Results of the recovery experiments performed on various amounts of benzoic acid and the determination of miconazole in cream confirmed the applicability of the method to complex formulations. 

As it turns out, there are pharmaceutical implications associated with the polymorphism of glycerol esters, since phase transformation reactions caused by the melting and solidification of these compounds during formulation can have profound effects on the quality of products. For instance, during the development of an oil-in-water cream formulation, syneresis of the aqueous phase was observed upon using certain sources of glyceryl monostearate [13]. Primarily through the use of variable temperature X-ray diffraction, it was learned that... 

The presence and state of solid lipid nanoparticles incorporated into semisolid formulations have also been investigated by DSC [77,83,84]. Using this method, de Vringer and de Ronde were able to draw conclusions on the preparation-dependent distribution of the matrix lipid of their particles in the different phases of a cream formulation [77]. 

Figure 2 shows the influence of the different phase transitions on the rheological characteristics of a vaginal cream formulation containing cetostearyl alcohol and Poly-sorbate 60 as the emulsifying wax. Incomplete transition of two observable polymorphs... 

Figure 3 (A) Cooling and (B) heating thermal scanning rheograms for a vaginal cream formulation. The dashed vertical line indicates the 38° C point in both plots. This is clearly the initiation temperature of the phase transition leading to increased apparent viscosity during both heating and cooling.

Emollients are often added to cream formulations to modify either the characteristics of the pharmaceutical vehicle or the condition of the skin itself to promote penetration of the active ingredient to act either locally or systemically. The stratum corneum, being keratinized tissue, behaves as a semipermeable artificial membrane, and drug molecules can penetrate by passive diffusion. The rate of drug movement depends on the drug concentration in the vehicle, its aqueous solubility, and the oil/ water partition coefficient between the stratum corneum and the product s vehicle. Commonly used emollients include glycerin, mineral oil, petrolatum, isopropyl pal-mitate, and isopropyl myristate. 

Various marine and vegetable gums are currently in wide use in ice cream formulations. Shown to inhibit the formation of lactose crystal nuclei, they have been the principal factor responsible for the reduced incidence of sandiness in ice cream in recent years (Nickerson 1962). 

The most commonly described USP procedure for quantification is the scrap and elution approach. Low analyte recoveries can occur but can be minimized by using polar organic solvents such as methanol, ethanol, or acetone. Generally, analytes with high-Rf values can be desorbed with high recoveries by using the mobile phase. One example of this procedure is the USP assay procedure of the steroid methyl prednisolone acetate in cream formulation. This steroid is separated from its excipients by TLC, extracted from the sorbent, derivatized, and measured spectrophotometrically. 

FIGURE 8.5 Patient with lamellar Ichthyosis (due to TGM1 mutations) who twice daily for 2 mo. received a cream formulation containing lactic acid (5%) and propylene glycol (20%) on the right arm as compared to on the left arm (Reproduced from. ..31)... 

Ganemo, A., Virtanen, M., and Vahlquist, A., Improved topical treatmentof lamellar ichthyosis adouble blind study of four different cream formulations, Br. J. Dermatol., 141, 1027,1999. 

Gisby, J. and Bryant, J., Efficacy of new cream formulation of mupirocin comparison with oral and topical agents in experimental skin infections. Antimicrob. Agents Chemother. 44, 255-260, 2000. 

In one of your hand cream formulation there was no mineral oil. What characteristics was observed in the absence of mineral oil Explain. 

Selection of an appropriate base for an ointment or cream formulation depends on the type of activity desired (e.g., topical or percutaneous absorption), compatibility with other components, physicochemical and microbial stability of the product, ease of manufacture, pourability and spreadability of the formulation, duration of contact, chances of hypersensitivity reactions, and ease of washing from the site of application. In addition, bases that are used in ophthalmic preparations should be nonirritating and should soften at body temperatures. White petrolatum and liquid petrolatum are generally used in ophthalmic preparations. Table 1 summarizes... 

Levinson, R. S., Mitan, S. J., Steinmetz, J. I., Gattermeir, D. J., Schumacher, R. J., and Joffrion, J. L. (2005), An open-label, two-period, crossover study of the systemic bioavailability in healthy women of clindamycin phosphate from two vaginal cream formulations, Clin. Ther., 27,1894-1900. 

Francois, M., Snoeckx, E., Putteman, R, Wouters, F., De Proost, E., Delaet, U., Peeters, J., and Brewster, M. E. (2003), A mucoadhesive, cyclodextrin-based vaginal cream formulation of itraconazole, AAPS PharmSci, 5, E5. 

Brown, D., Henzl, M. R., and Kaufman, R. H. (1999), Butoconazole nitrate 2% for vulvovaginal candidiasis. New, single-dose vaginal cream formulation vs. seven-day treatment with miconazole nitrate. Gynazole 1 Study Group, /. Reprod. Med., 44, 933-938. 

Emulsifiers used in cream formulations may be classified into three different categories anionic, cationic, and non-ionic emulsifiers. 

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