Compendium of the most significant studies with reference to properties, intake, effects.

Mah, C. S., Kochhar, J. S., Ong, P. S., & Kang, L. (2013). A miniaturized flow-through cell to evaluate skin permeation of endoxifen. International journal of pharmaceutics, 441(1-2), 433-440.

Abstract. Endoxifen, an anti-estrogenic agent, has been recently implicated in the use of breast cancer. Its physicochemical properties make it a good candidate for transdermal delivery. However, as an investigative drug, its limited supply makes it difficult to conduct extensive pre-formulation studies. To address this issue, a miniaturized flow-through diffusion cell has been fabricated that utilized minimal amounts of the drug for in vitro skin permeation studies. The novel flow-through cells have been validated against horizontal diffusion cells and shown to cause no noticeable damage to the applied skin, as observed by histological sectioning. The cells were also demonstrated to be useful in search of suitable enhancers for endoxifen. Endoxifen permeation using permeation enhancers was tested by using this new device and limonene was found to achieve highest flux, attaining the requirement for clinical applications. The fabricated cells can thus be useful in carrying out pre-formulation studies for expensive, new drug entities, both in industrial as well as academic research.

AHN, H. Y., MYUNG, K. B., HAHM, J. H., & KOOK, H. I. (1985). An Experimental Study on Comedogenicity of Several External Contactants. Korean Journal of Dermatology, 620-629.

Abstract. The present study was performed to evaluate the comedogenicity of several cosmetic ingredients, vegetable oils, steroid and sulfur. The test materials were applied to one ear canal of rabbits for 6 weekdays for 2 weeks. The results were as follows l. Among the 14 cosmetic ingredients, no comedogenicity was shown in propylene glycol and petrolatum, mild comedogencity in squalene, acetylated lanolin, polyethylene glycol, cetyl aIcohol and Tween 80. Propylene glycol, sodium lauryl sulfate and oleic acid showed moderate comedogenicity. Severe comedogenicity was observed in myristyl myristate, isopropyl myristate, butyl stearate and myristyl lactate. 2. Moderate to severe comedogenicity was shown in olive oil, sesame oil and corn oil and moderate comedogenicity in sulfur (8%) and betamethasone dipropionate (0.06%) R. Histopathologic grading were paralleled the findings of the naked eye.

Zamansky, M., Zehavi, N. A., Ben-Shabat, S., & Sintov, A. C. (2021). Characterization of nanoparticles made of ethyl cellulose and stabilizing lipids: Mode of manufacturing, size modulation, and study of their effect on keratinocytes. International Journal of Pharmaceutics, 607, 121003.

Abstract. We have developed an ethyl cellulose-based nanoparticulate system for encapsulation of sparingly soluble active pharmaceutical ingredients. Cannabidiol (CBD) and curcumin (CUR) were selected as model active ingredients. Using the nanoprecipitation method, nanoparticles ranged between 150 nm and 250 nm were obtained with an entrapment efficiency of >80%. It has been shown that incorporation of stabilizing lipids significantly reduced aggregation, increased the yield and the active ingredient-to-polymer ratio. In this study, we have explored the influence of process parameters on the extent of new particle core formation: chemical properties of the active ingredients, polymer concentrations, non-solvent addition rate, and the volume of the organic solvent for nanoparticle size control. The relationship between the particle radius [R] and the polymer concentration [Pol] was defined by R ∝ [Pol]n when n < ⅓. The extent of polymer supersaturation was related to the value of n, when the high polymer supersaturation increased the formation rate of new particle cores while decreasing polymer layering on the existing cores and the nanoparticles size. The obtained nanoparticles have shown low toxicity in keratinocytes, however, higher loadings of CUR or CBD resulted in increased toxicity. The nanoparticles effectively internalized into keratinocytes, implying their applicability for dermal delivery.

Lundberg, P. (1999). DECOS and SCG basis for an occupational standard lactate esters.

Abstract. Lactate esters (esters of lactic acid) are used as food additives, in pharmaceuticals and cosmetics and are currently finding new uses as solvents. Lactate esters are hydrolyzed to lactic acid and alcohol. Lactic acid is a normal metabolite in humans. The toxicity of lactate esters is most likely due to the acidity of lactic acid. Based on animal data the critical effect of occupational exposure to lactate esters is irritation of the mucous membranes in nose and throat. Only unpublished studies in humans are available.

Lactate, C. Final Report on the Safety Assessment of Cetyl lactate and Myristyl lactate.

Abstract. Cetyl Lactate and Myristyl Lactate are the esters of lactic acid and either cetyl or myristyl alcohol. They are used in a wide variety of cosmetic products up to a maximum concentration of 25%. The acute oral LD50 of Cetyl Lactate is estimated from studies with rats to be greater than 20 g/kg. Cetyl Lactate was shown to be minimally irritating to rabbit skin and nonirritating or only slightly irritating to rabbit eyes in Draize irritation tests. At 25%, Cetyl Lactate produced no signs of toxicity or irritation in a 30-day rabbit-skin irritation study. Cetyl Lactate was found to be minimally irritating and nonsensitizing to human skin at concentrations up to 5%. The acute oral LD50 of Myristyl Lactate is estimated from studies with rats to be greater than 20 g/kg. Myristyl Lactate was shown to be minimally irritating in Draize primary skin irritation tests, but one contradictory study concluded that undiluted Myristyl Lactate produced moderate irritation. It produced no signs of ocular irritation in Draize rabbit eye irritation tests. Mild irritation was elicited by a formulation in a modified Draize rabbit skin irritation test. The same formulation was found to be nonirritating and nonsensitizing in a human repeated insult patch study. Based on the available information, it is concluded that Cetyl Lactate and Myristyl Lactate are safe in the present practices of use.

Khizer, Z., Sadia, A., Sharma, R., Farhaj, S., Nirwan, J. S., Kakadia, P. G., ... & Ghori, M. U. (2021). Drug delivery approaches for managing overactive bladder (Oab): A systematic review. Pharmaceuticals, 14(5), 409.

Abstract. Overactive bladder syndrome (OAB) is characterised by urgency symptoms, with or without urgency incontinence, usually with frequency and nocturia and severely affects the quality of life. This systematic review evaluates the various drug delivery strategies used in practice to manage OAB. Advanced drug delivery strategies alongside traditional strategies were comprehensively analysed and comparatively evaluated. The present review was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines. A total of 24 studies reporting the development of novel formulations for the treatment of OAB were considered eligible and were further categorised according to the route of drug administration. The review found that various drug delivery routes (transdermal, intravesicular, oral, vaginal and intramuscular) are used for the administration of drugs for managing OAB, however, the outcomes illustrated the marked potential of transdermal drug delivery route. The findings of the current review are expected to be helpful for pharmaceutical scientists to better comprehend the existing literature and challenges and is anticipated to provide a basis for designing and fabricating novel drug delivery systems to manage OAB

KAiHo, F., KOIKE, R., NOMURA, H., HARA, H., MARUOKA, K., DOHI, M., & KATO, Y. (1989). Enhancing effect of cetyl lactate on the percutaneous absorption of indomethacin in rats. Chemical and pharmaceutical bulletin, 37(4), 1114-1116.

Abstract. The enhancing effect of cetyl lactate (CL) on the percutaneous absorption of indomethacin (ID) from test solutions in propylene glycol (PG) was investigated by using the abdominal skin of rats in vivo.The percutaneous absorption rate of ID from 1 or 3% CL-PG test solution through the intact skin of rats was observed to be faster than that from the control solution (without CL). The bioavailability of ID was about 0.04% for the control solution, 2.2% for 1% CL-PG and 6.8% for 3% CL-PG test solutions. These results suggest that CL functions as an enhancer for the percutaneous absorption of ID. Furthermore, marked enhancing effects on percutaneous absorption of ID were obtained at a concentration greater than 1% CL in PG.In order to elucidate the mode of action of CL as an absorption enhancer, the percutaneous absorption of ID from the control solution and 3% CL-PG test solution through damaged skin from which the stratum corneum had been stripped was additionally investigated. It was confirmed that CL acts on the stratum corneum to produce its effect.